evanw/esbuild
### [`v0.18.0`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#0180)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.19...v0.18.0)
**This release deliberately contains backwards-incompatible changes.** To avoid automatically picking up releases like this, you should either be pinning the exact version of `esbuild` in your `package.json` file (recommended) or be using a version range syntax that only accepts patch upgrades such as `^0.17.0` or `~0.17.0`. See npm's documentation about [semver](https://docs.npmjs.com/cli/v6/using-npm/semver/) for more information.
The breaking changes in this release mainly focus on fixing some long-standing issues with esbuild's handling of `tsconfig.json` files. Here are all the changes in this release, in detail:
- Add a way to try esbuild online ([#797](https://togithub.com/evanw/esbuild/issues/797))
There is now a way to try esbuild live on esbuild's website without installing it: https://esbuild.github.io/try/. In addition to being able to more easily evaluate esbuild, this should also make it more efficient to generate esbuild bug reports. For example, you can use it to compare the behavior of different versions of esbuild on the same input. The state of the page is stored in the URL for easy sharing. Many thanks to [@hyrious](https://togithub.com/hyrious) for creating https://hyrious.me/esbuild-repl/, which was the main inspiration for this addition to esbuild's website.
Two forms of build options are supported: either CLI-style ([example](https://esbuild.github.io/try/#dAAwLjE3LjE5AC0tbG9hZGVyPXRzeCAtLW1pbmlmeSAtLXNvdXJjZW1hcABsZXQgZWw6IEpTWC5FbGVtZW50ID0gPGRpdiAvPg)) or JS-style ([example](https://esbuild.github.io/try/#dAAwLjE3LjE5AHsKICBsb2FkZXI6ICd0c3gnLAogIG1pbmlmeTogdHJ1ZSwKICBzb3VyY2VtYXA6IHRydWUsCn0AbGV0IGVsOiBKU1guRWxlbWVudCA9IDxkaXYgLz4)). Both are converted into a JS object that's passed to esbuild's WebAssembly API. The CLI-style argument parser is a custom one that simulates shell quoting rules, and the JS-style argument parser is also custom and parses a superset of JSON (basically JSON5 + regular expressions). So argument parsing is an approximate simulation of what happens for real but hopefully it should be close enough.
- Changes to esbuild's `tsconfig.json` support ([#3019](https://togithub.com/evanw/esbuild/issues/3019)):
This release makes the following changes to esbuild's `tsconfig.json` support:
- Using experimental decorators now requires `"experimentalDecorators": true` ([#104](https://togithub.com/evanw/esbuild/issues/104))
Previously esbuild would always compile decorators in TypeScript code using TypeScript's experimental decorator transform. Now that standard JavaScript decorators are close to being finalized, esbuild will now require you to use `"experimentalDecorators": true` to do this. This new requirement makes it possible for esbuild to introduce a transform for standard JavaScript decorators in TypeScript code in the future. Such a transform has not been implemented yet, however.
- TypeScript's `target` no longer affects esbuild's `target` ([#2628](https://togithub.com/evanw/esbuild/issues/2628))
Some people requested that esbuild support TypeScript's `target` setting, so support for it was added (in [version 0.12.4](https://togithub.com/evanw/esbuild/releases/v0.12.4)). However, esbuild supports reading from multiple `tsconfig.json` files within a single build, which opens up the possibility that different files in the build have different language targets configured. There isn't really any reason to do this and it can lead to unexpected results. So with this release, the `target` setting in `tsconfig.json` will no longer affect esbuild's own `target` setting. You will have to use esbuild's own target setting instead (which is a single, global value).
- TypeScript's `jsx` setting no longer causes esbuild to preserve JSX syntax ([#2634](https://togithub.com/evanw/esbuild/issues/2634))
TypeScript has a setting called [`jsx`](https://www.typescriptlang.org/tsconfig#jsx) that controls how to transform JSX into JS. The tool-agnostic transform is called `react`, and the React-specific transform is called `react-jsx` (or `react-jsxdev`). There is also a setting called `preserve` which indicates JSX should be passed through untransformed. Previously people would run esbuild with `"jsx": "preserve"` in their `tsconfig.json` files and then be surprised when esbuild preserved their JSX. So with this release, esbuild will now ignore `"jsx": "preserve"` in `tsconfig.json` files. If you want to preserve JSX syntax with esbuild, you now have to use `--jsx=preserve`.
Note: Some people have suggested that esbuild's equivalent `jsx` setting override the one in `tsconfig.json`. However, some projects need to legitimately have different files within the same build use different transforms (i.e. `react` vs. `react-jsx`) and having esbuild's global `jsx` setting override `tsconfig.json` would prevent this from working. This release ignores `"jsx": "preserve"` but still allows other `jsx` values in `tsconfig.json` files to override esbuild's global `jsx` setting to keep the ability for multiple files within the same build to use different transforms.
- `useDefineForClassFields` behavior has changed ([#2584](https://togithub.com/evanw/esbuild/issues/2584), [#2993](https://togithub.com/evanw/esbuild/issues/2993))
Class fields in TypeScript look like this (`x` is a class field):
```js
class Foo {
x = 123
}
```
TypeScript has legacy behavior that uses assignment semantics instead of define semantics for class fields when [`useDefineForClassFields`](https://www.typescriptlang.org/tsconfig#useDefineForClassFields) is enabled (in which case class fields in TypeScript behave differently than they do in JavaScript, which is arguably "wrong").
This legacy behavior exists because TypeScript added class fields to TypeScript before they were added to JavaScript. The TypeScript team decided to go with assignment semantics and shipped their implementation. Much later on TC39 decided to go with define semantics for class fields in JavaScript instead. This behaves differently if the base class has a setter with the same name:
```js
class Base {
set x(_) {
console.log('x:', _)
}
}
// useDefineForClassFields: false
class AssignSemantics extends Base {
constructor() {
super()
this.x = 123
}
}
// useDefineForClassFields: true
class DefineSemantics extends Base {
constructor() {
super()
Object.defineProperty(this, 'x', { value: 123 })
}
}
console.log(
new AssignSemantics().x, // Calls the setter
new DefineSemantics().x // Doesn't call the setter
)
```
When you run `tsc`, the value of `useDefineForClassFields` defaults to `false` when it's not specified and the `target` in `tsconfig.json` is present but earlier than `ES2022`. This sort of makes sense because the class field language feature was added in ES2022, so before ES2022 class fields didn't exist (and thus TypeScript's legacy behavior is active). However, TypeScript's `target` setting currently defaults to `ES3` which unfortunately means that the `useDefineForClassFields` setting currently defaults to false (i.e. to "wrong"). In other words if you run `tsc` with all default settings, class fields will behave incorrectly.
Previously esbuild tried to do what `tsc` did. That meant esbuild's version of `useDefineForClassFields` was `false` by default, and was also `false` if esbuild's `--target=` was present but earlier than `es2022`. However, TypeScript's legacy class field behavior is becoming increasingly irrelevant and people who expect class fields in TypeScript to work like they do in JavaScript are confused when they use esbuild with default settings. It's also confusing that the behavior of class fields would change if you changed the language target (even though that's exactly how TypeScript works).
So with this release, esbuild will now only use the information in `tsconfig.json` to determine whether `useDefineForClassFields` is true or not. Specifically `useDefineForClassFields` will be respected if present, otherwise it will be `false` if `target` is present in `tsconfig.json` and is `ES2021` or earlier, otherwise it will be `true`. Targets passed to esbuild's `--target=` setting will no longer affect `useDefineForClassFields`.
Note that this means different directories in your build can have different values for this setting since esbuild allows different directories to have different `tsconfig.json` files within the same build. This should let you migrate your code one directory at a time without esbuild's `--target=` setting affecting the semantics of your code.
- Add support for `verbatimModuleSyntax` from TypeScript 5.0
TypeScript 5.0 added a new option called [`verbatimModuleSyntax`](https://www.typescriptlang.org/tsconfig#verbatimModuleSyntax) that deprecates and replaces two older options, `preserveValueImports` and `importsNotUsedAsValues`. Setting `verbatimModuleSyntax` to true in `tsconfig.json` tells esbuild to not drop unused import statements. Specifically esbuild now treats `"verbatimModuleSyntax": true` as if you had specified both `"preserveValueImports": true` and `"importsNotUsedAsValues": "preserve"`.
- Add multiple inheritance for `tsconfig.json` from TypeScript 5.0
TypeScript 5.0 now allows [multiple inheritance for `tsconfig.json` files](https://devblogs.microsoft.com/typescript/announcing-typescript-5-0/#supporting-multiple-configuration-files-in-extends). You can now pass an array of filenames via the `extends` parameter and your `tsconfig.json` will start off containing properties from all of those configuration files, in order. This release of esbuild adds support for this new TypeScript feature.
- Remove support for `moduleSuffixes` ([#2395](https://togithub.com/evanw/esbuild/issues/2395))
The community has requested that esbuild remove support for TypeScript's `moduleSuffixes` feature, so it has been removed in this release. Instead you can use esbuild's `--resolve-extensions=` feature to select which module suffix you want to build with.
- Apply `--tsconfig=` overrides to `stdin` and virtual files ([#385](https://togithub.com/evanw/esbuild/issues/385), [#2543](https://togithub.com/evanw/esbuild/issues/2543))
When you override esbuild's automatic `tsconfig.json` file detection with `--tsconfig=` to pass a specific `tsconfig.json` file, esbuild previously didn't apply these settings to source code passed via the `stdin` API option or to TypeScript files from plugins that weren't in the `file` namespace. This release changes esbuild's behavior so that settings from `tsconfig.json` also apply to these source code files as well.
- Support `--tsconfig-raw=` in build API calls ([#943](https://togithub.com/evanw/esbuild/issues/943), [#2440](https://togithub.com/evanw/esbuild/issues/2440))
Previously if you wanted to override esbuild's automatic `tsconfig.json` file detection, you had to create a new `tsconfig.json` file and pass the file name to esbuild via the `--tsconfig=` flag. With this release, you can now optionally use `--tsconfig-raw=` instead to pass the contents of `tsconfig.json` to esbuild directly instead of passing the file name. For example, you can now use `--tsconfig-raw={"compilerOptions":{"experimentalDecorators":true}}` to enable TypeScript experimental decorators directly using a command-line flag (assuming you escape the quotes correctly using your current shell's quoting rules). The `--tsconfig-raw=` flag previously only worked with transform API calls but with this release, it now works with build API calls too.
- Ignore all `tsconfig.json` files in `node_modules` ([#276](https://togithub.com/evanw/esbuild/issues/276), [#2386](https://togithub.com/evanw/esbuild/issues/2386))
This changes esbuild's behavior that applies `tsconfig.json` to all files in the subtree of the directory containing `tsconfig.json`. In version 0.12.7, esbuild started ignoring `tsconfig.json` files inside `node_modules` folders. The rationale is that people typically do this by mistake and that doing this intentionally is a rare use case that doesn't need to be supported. However, this change only applied to certain syntax-specific settings (e.g. `jsxFactory`) but did not apply to path resolution settings (e.g. `paths`). With this release, esbuild will now ignore all `tsconfig.json` files in `node_modules` instead of only ignoring certain settings.
- Ignore `tsconfig.json` when resolving paths within `node_modules` ([#2481](https://togithub.com/evanw/esbuild/issues/2481))
Previously fields in `tsconfig.json` related to path resolution (e.g. `paths`) were respected for all files in the subtree containing that `tsconfig.json` file, even within a nested `node_modules` subdirectory. This meant that a project's `paths` settings could potentially affect any bundled packages. With this release, esbuild will no longer use `tsconfig.json` settings during path resolution inside nested `node_modules` subdirectories.
- Prefer `.js` over `.ts` within `node_modules` ([#3019](https://togithub.com/evanw/esbuild/issues/3019))
The default list of implicit extensions that esbuild will try appending to import paths contains `.ts` before `.js`. This makes it possible to bundle TypeScript projects that reference other files in the project using extension-less imports (e.g. `./some-file` to load `./some-file.ts` instead of `./some-file.js`). However, this behavior is undesirable within `node_modules` directories. Some package authors publish both their original TypeScript code and their compiled JavaScript code side-by-side. In these cases, esbuild should arguably be using the compiled JavaScript files instead of the original TypeScript files because the TypeScript compilation settings for files within the package should be determined by the package author, not the user of esbuild. So with this release, esbuild will now prefer implicit `.js` extensions over `.ts` when searching for import paths within `node_modules`.
These changes are intended to improve esbuild's compatibility with `tsc` and reduce the number of unfortunate behaviors regarding `tsconfig.json` and esbuild.
- Add a workaround for bugs in Safari 16.2 and earlier ([#3072](https://togithub.com/evanw/esbuild/issues/3072))
Safari's JavaScript parser had a bug (which has now been fixed) where at least something about unary/binary operators nested inside default arguments nested inside either a function or class expression was incorrectly considered a syntax error if that expression was the target of a property assignment. Here are some examples that trigger this Safari bug:
❱ x(function (y = -1) {}.z = 2)
SyntaxError: Left hand side of operator '=' must be a reference.
❱ x(class { f(y = -1) {} }.z = 2)
SyntaxError: Left hand side of operator '=' must be a reference.
It's not clear what the exact conditions are that trigger this bug. However, a workaround for this bug appears to be to post-process your JavaScript to wrap any in function and class declarations that are the direct target of a property access expression in parentheses. That's the workaround that UglifyJS applies for this issue: [mishoo/UglifyJS#2056](https://togithub.com/mishoo/UglifyJS/pull/2056). So that's what esbuild now does starting with this release:
```js
// Original code
x(function (y = -1) {}.z = 2, class { f(y = -1) {} }.z = 2)
// Old output (with --minify --target=safari16.2)
x(function(c=-1){}.z=2,class{f(c=-1){}}.z=2);
// New output (with --minify --target=safari16.2)
x((function(c=-1){}).z=2,(class{f(c=-1){}}).z=2);
```
This fix is not enabled by default. It's only enabled when `--target=` contains Safari 16.2 or earlier, such as with `--target=safari16.2`. You can also explicitly enable or disable this specific transform (called `function-or-class-property-access`) with `--supported:function-or-class-property-access=false`.
- Fix esbuild's TypeScript type declarations to forbid unknown properties ([#3089](https://togithub.com/evanw/esbuild/issues/3089))
Version 0.17.0 of esbuild introduced a specific form of function overloads in the TypeScript type definitions for esbuild's API calls that looks like this:
```ts
interface TransformOptions {
legalComments?: 'none' | 'inline' | 'eof' | 'external'
}
interface TransformResult {
legalComments: string | (ProvidedOptions['legalComments'] extends 'external' ? never : undefined)
}
declare function transformSync(input: string, options?: ProvidedOptions): TransformResult
declare function transformSync(input: string, options?: TransformOptions): TransformResult
```
This more accurately reflects how esbuild's JavaScript API behaves. The result object returned by `transformSync` only has the `legalComments` property if you pass `legalComments: 'external'`:
```ts
// These have type "string | undefined"
transformSync('').legalComments
transformSync('', { legalComments: 'eof' }).legalComments
// This has type "string"
transformSync('', { legalComments: 'external' }).legalComments
```
However, this form of function overloads unfortunately allows typos (e.g. `egalComments`) to pass the type checker without generating an error as TypeScript allows all objects with unknown properties to extend `TransformOptions`. These typos result in esbuild's API throwing an error at run-time.
To prevent typos during type checking, esbuild's TypeScript type definitions will now use a different form that looks like this:
```ts
type SameShape = In & { [Key in Exclude]: never }
interface TransformOptions {
legalComments?: 'none' | 'inline' | 'eof' | 'external'
}
interface TransformResult {
legalComments: string | (ProvidedOptions['legalComments'] extends 'external' ? never : undefined)
}
declare function transformSync(input: string, options?: SameShape): TransformResult
```
This change should hopefully not affect correct code. It should hopefully introduce type errors only for incorrect code.
- Fix CSS nesting transform for pseudo-elements ([#3119](https://togithub.com/evanw/esbuild/issues/3119))
This release fixes esbuild's CSS nesting transform for pseudo-elements (e.g. `::before` and `::after`). The CSS nesting specification says that [the nesting selector does not work with pseudo-elements](https://www.w3.org/TR/css-nesting-1/#ref-for-matches-pseudo%E2%91%A0). This can be seen in the example below: esbuild does not carry the parent pseudo-element `::before` through the nesting selector `&`. However, that doesn't apply to pseudo-elements that are within the same selector. Previously esbuild had a bug where it considered pseudo-elements in both locations as invalid. This release changes esbuild to only consider those from the parent selector invalid, which should align with the specification:
```css
/* Original code */
a, b::before {
&.c, &::after {
content: 'd';
}
}
/* Old output (with --target=chrome90) */
a:is(.c, ::after) {
content: "d";
}
/* New output (with --target=chrome90) */
a.c,
a::after {
content: "d";
}
```
- Forbid `&` before a type selector in nested CSS
The people behind the work-in-progress CSS nesting specification have very recently [decided to forbid nested CSS that looks like `&div`](https://togithub.com/w3c/csswg-drafts/issues/8662#issuecomment-1514977935). You will have to use either `div&` or `&:is(div)` instead. This release of esbuild has been updated to take this new change into consideration. Doing this now generates a warning. The suggested fix is slightly different depending on where in the overall selector it happened:
▲ [WARNING] Cannot use type selector "input" directly after nesting selector "&" [css-syntax-error]
example.css:2:3:
2 │ &input {
│ ~~~~~
╵ :is(input)
CSS nesting syntax does not allow the "&" selector to come before a type selector. You can wrap
this selector in ":is()" as a workaround. This restriction exists to avoid problems with SASS
nesting, where the same syntax means something very different that has no equivalent in real CSS
(appending a suffix to the parent selector).
▲ [WARNING] Cannot use type selector "input" directly after nesting selector "&" [css-syntax-error]
example.css:6:8:
6 │ .form &input {
│ ~~~~~~
╵ input&
CSS nesting syntax does not allow the "&" selector to come before a type selector. You can move
the "&" to the end of this selector as a workaround. This restriction exists to avoid problems
with SASS nesting, where the same syntax means something very different that has no equivalent in
real CSS (appending a suffix to the parent selector).
### [`v0.17.19`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01719)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.18...v0.17.19)
- Fix CSS transform bugs with nested selectors that start with a combinator ([#3096](https://togithub.com/evanw/esbuild/issues/3096))
This release fixes several bugs regarding transforming nested CSS into non-nested CSS for older browsers. The bugs were due to lack of test coverage for nested selectors with more than one compound selector where they all start with the same combinator. Here's what some problematic cases look like before and after these fixes:
```css
/* Original code */
.foo {
> &a,
> &b {
color: red;
}
}
.bar {
> &a,
+ &b {
color: green;
}
}
/* Old output (with --target=chrome90) */
.foo :is(> .fooa, > .foob) {
color: red;
}
.bar :is(> .bara, + .barb) {
color: green;
}
/* New output (with --target=chrome90) */
.foo > :is(a.foo, b.foo) {
color: red;
}
.bar > a.bar,
.bar + b.bar {
color: green;
}
```
- Fix bug with TypeScript parsing of instantiation expressions followed by `=` ([#3111](https://togithub.com/evanw/esbuild/issues/3111))
This release fixes esbuild's TypeScript-to-JavaScript conversion code in the case where a potential instantiation expression is followed immediately by a `=` token (such that the trailing `>` becomes a `>=` token). Previously esbuild considered that to still be an instantiation expression, but the official TypeScript compiler considered it to be a `>=` operator instead. This release changes esbuild's interpretation to match TypeScript. This edge case currently [appears to be problematic](https://sucrase.io/#transforms=typescript\&compareWithTypeScript=true\&code=x%3Cy%3E%3Da%3Cb%3Cc%3E%3E\(\)) for other TypeScript-to-JavaScript converters as well:
| Original code | TypeScript | esbuild 0.17.18 | esbuild 0.17.19 | Sucrase | Babel |
|---|---|---|---|---|---|
| `x=a>()` | `x=a();` | `x=a();` | `x=a();` | `x=a()` | Invalid left-hand side in assignment expression |
- Avoid removing unrecognized directives from the directive prologue when minifying ([#3115](https://togithub.com/evanw/esbuild/issues/3115))
The [directive prologue](https://262.ecma-international.org/6.0/#sec-directive-prologues-and-the-use-strict-directive) in JavaScript is a sequence of top-level string expressions that come before your code. The only directives that JavaScript engines currently recognize are `use strict` and sometimes `use asm`. However, the people behind React have made up their own directive for their own custom dialect of JavaScript. Previously esbuild only preserved the `use strict` directive when minifying, although you could still write React JavaScript with esbuild using something like `--banner:js="'your directive here';"`. With this release, you can now put arbitrary directives in the entry point and esbuild will preserve them in its minified output:
```js
// Original code
'use wtf'; console.log(123)
// Old output (with --minify)
console.log(123);
// New output (with --minify)
"use wtf";console.log(123);
```
Note that this means esbuild will no longer remove certain stray top-level strings when minifying. This behavior is an intentional change because these stray top-level strings are actually part of the directive prologue, and could potentially have semantics assigned to them (as was the case with React).
- Improved minification of binary shift operators
With this release, esbuild's minifier will now evaluate the `<<` and `>>>` operators if the resulting code would be shorter:
```js
// Original code
console.log(10 << 10, 10 << 20, -123 >>> 5, -123 >>> 10);
// Old output (with --minify)
console.log(10<<10,10<<20,-123>>>5,-123>>>10);
// New output (with --minify)
console.log(10240,10<<20,-123>>>5,4194303);
```
### [`v0.17.18`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01718)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.17...v0.17.18)
- Fix non-default JSON import error with `export {} from` ([#3070](https://togithub.com/evanw/esbuild/issues/3070))
This release fixes a bug where esbuild incorrectly identified statements of the form `export { default as x } from "y" assert { type: "json" }` as a non-default import. The bug did not affect code of the form `import { default as x } from ...` (only code that used the `export` keyword).
- Fix a crash with an invalid subpath import ([#3067](https://togithub.com/evanw/esbuild/issues/3067))
Previously esbuild could crash when attempting to generate a friendly error message for an invalid [subpath import](https://nodejs.org/api/packages.html#subpath-imports) (i.e. an import starting with `#`). This happened because esbuild originally only supported the `exports` field and the code for that error message was not updated when esbuild later added support for the `imports` field. This crash has been fixed.
### [`v0.17.17`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01717)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.16...v0.17.17)
- Fix CSS nesting transform for top-level `&` ([#3052](https://togithub.com/evanw/esbuild/issues/3052))
Previously esbuild could crash with a stack overflow when lowering CSS nesting rules with a top-level `&`, such as in the code below. This happened because esbuild's CSS nesting transform didn't handle top-level `&`, causing esbuild to inline the top-level selector into itself. This release handles top-level `&` by replacing it with [the `:scope` pseudo-class](https://drafts.csswg.org/selectors-4/#the-scope-pseudo):
```css
/* Original code */
&,
a {
.b {
color: red;
}
}
/* New output (with --target=chrome90) */
:is(:scope, a) .b {
color: red;
}
```
- Support `exports` in `package.json` for `extends` in `tsconfig.json` ([#3058](https://togithub.com/evanw/esbuild/issues/3058))
TypeScript 5.0 added the ability to use `extends` in `tsconfig.json` to reference a path in a package whose `package.json` file contains an `exports` map that points to the correct location. This doesn't automatically work in esbuild because `tsconfig.json` affects esbuild's path resolution, so esbuild's normal path resolution logic doesn't apply.
This release adds support for doing this by adding some additional code that attempts to resolve the `extends` path using the `exports` field. The behavior should be similar enough to esbuild's main path resolution logic to work as expected.
Note that esbuild always treats this `extends` import as a `require()` import since that's what TypeScript appears to do. Specifically the `require` condition will be active and the `import` condition will be inactive.
- Fix watch mode with `NODE_PATH` ([#3062](https://togithub.com/evanw/esbuild/issues/3062))
Node has a rarely-used feature where you can extend the set of directories that node searches for packages using the `NODE_PATH` environment variable. While esbuild supports this too, previously a bug prevented esbuild's watch mode from picking up changes to imported files that were contained directly in a `NODE_PATH` directory. You're supposed to use `NODE_PATH` for packages, but some people abuse this feature by putting files in that directory instead (e.g. `node_modules/some-file.js` instead of `node_modules/some-pkg/some-file.js`). The watch mode bug happens when you do this because esbuild first tries to read `some-file.js` as a directory and then as a file. Watch mode was incorrectly waiting for `some-file.js` to become a valid directory. This release fixes this edge case bug by changing watch mode to watch `some-file.js` as a file when this happens.
### [`v0.17.16`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01716)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.15...v0.17.16)
- Fix CSS nesting transform for triple-nested rules that start with a combinator ([#3046](https://togithub.com/evanw/esbuild/issues/3046))
This release fixes a bug with esbuild where triple-nested CSS rules that start with a combinator were not transformed correctly for older browsers. Here's an example of such a case before and after this bug fix:
```css
/* Original input */
.a {
color: red;
> .b {
color: green;
> .c {
color: blue;
}
}
}
/* Old output (with --target=chrome90) */
.a {
color: red;
}
.a > .b {
color: green;
}
.a .b > .c {
color: blue;
}
/* New output (with --target=chrome90) */
.a {
color: red;
}
.a > .b {
color: green;
}
.a > .b > .c {
color: blue;
}
```
- Support `--inject` with a file loaded using the `copy` loader ([#3041](https://togithub.com/evanw/esbuild/issues/3041))
This release now allows you to use `--inject` with a file that is loaded using the `copy` loader. The `copy` loader copies the imported file to the output directory verbatim and rewrites the path in the `import` statement to point to the copied output file. When used with `--inject`, this means the injected file will be copied to the output directory as-is and a bare `import` statement for that file will be inserted in any non-copy output files that esbuild generates.
Note that since esbuild doesn't parse the contents of copied files, esbuild will not expose any of the export names as usable imports when you do this (in the way that esbuild's `--inject` feature is typically used). However, any side-effects that the injected file has will still occur.
### [`v0.17.15`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01715)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.14...v0.17.15)
- Allow keywords as type parameter names in mapped types ([#3033](https://togithub.com/evanw/esbuild/issues/3033))
TypeScript allows type keywords to be used as parameter names in mapped types. Previously esbuild incorrectly treated this as an error. Code that does this is now supported:
```ts
type Foo = 'a' | 'b' | 'c'
type A = { [keyof in Foo]: number }
type B = { [infer in Foo]: number }
type C = { [readonly in Foo]: number }
```
- Add annotations for re-exported modules in node ([#2486](https://togithub.com/evanw/esbuild/issues/2486), [#3029](https://togithub.com/evanw/esbuild/issues/3029))
Node lets you import named imports from a CommonJS module using ESM import syntax. However, the allowed names aren't derived from the properties of the CommonJS module. Instead they are derived from an arbitrary syntax-only analysis of the CommonJS module's JavaScript AST.
To accommodate node doing this, esbuild's ESM-to-CommonJS conversion adds a special non-executable "annotation" for node that describes the exports that node should expose in this scenario. It takes the form `0 && (module.exports = { ... })` and comes at the end of the file (`0 && expr` means `expr` is never evaluated).
Previously esbuild didn't do this for modules re-exported using the `export * from` syntax. Annotations for these re-exports will now be added starting with this release:
```js
// Original input
export { foo } from './foo'
export * from './bar'
// Old output (with --format=cjs --platform=node)
...
0 && (module.exports = {
foo
});
// New output (with --format=cjs --platform=node)
...
0 && (module.exports = {
foo,
...require("./bar")
});
```
Note that you need to specify both `--format=cjs` and `--platform=node` to get these node-specific annotations.
- Avoid printing an unnecessary space in between a number and a `.` ([#3026](https://togithub.com/evanw/esbuild/pull/3026))
JavaScript typically requires a space in between a number token and a `.` token to avoid the `.` being interpreted as a decimal point instead of a member expression. However, this space is not required if the number token itself contains a decimal point, an exponent, or uses a base other than 10. This release of esbuild now avoids printing the unnecessary space in these cases:
```js
// Original input
foo(1000 .x, 0 .x, 0.1 .x, 0.0001 .x, 0xFFFF_0000_FFFF_0000 .x)
// Old output (with --minify)
foo(1e3 .x,0 .x,.1 .x,1e-4 .x,0xffff0000ffff0000 .x);
// New output (with --minify)
foo(1e3.x,0 .x,.1.x,1e-4.x,0xffff0000ffff0000.x);
```
- Fix server-sent events with live reload when writing to the file system root ([#3027](https://togithub.com/evanw/esbuild/issues/3027))
This release fixes a bug where esbuild previously failed to emit server-sent events for live reload when `outdir` was the file system root, such as `/`. This happened because `/` is the only path on Unix that cannot have a trailing slash trimmed from it, which was fixed by improved path handling.
### [`v0.17.14`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01714)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.13...v0.17.14)
- Allow the TypeScript 5.0 `const` modifier in object type declarations ([#3021](https://togithub.com/evanw/esbuild/issues/3021))
The new TypeScript 5.0 `const` modifier was added to esbuild in version 0.17.5, and works with classes, functions, and arrow expressions. However, support for it wasn't added to object type declarations (e.g. interfaces) due to an oversight. This release adds support for these cases, so the following TypeScript 5.0 code can now be built with esbuild:
```ts
interface Foo { (): T }
type Bar = { new (): T }
```
- Implement preliminary lowering for CSS nesting ([#1945](https://togithub.com/evanw/esbuild/issues/1945))
Chrome has [implemented the new CSS nesting specification](https://developer.chrome.com/articles/css-nesting/) in version 112, which is currently in beta but will become stable very soon. So CSS nesting is now a part of the web platform!
This release of esbuild can now transform nested CSS syntax into non-nested CSS syntax for older browsers. The transformation relies on the `:is()` pseudo-class in many cases, so the transformation is only guaranteed to work when targeting browsers that support `:is()` (e.g. Chrome 88+). You'll need to set esbuild's [`target`](https://esbuild.github.io/api/#target) to the browsers you intend to support to tell esbuild to do this transformation. You will get a warning if you use CSS nesting syntax with a `target` which includes older browsers that don't support `:is()`.
The lowering transformation looks like this:
```css
/* Original input */
a.btn {
color: #333;
&:hover { color: #444 }
&:active { color: #555 }
}
/* New output (with --target=chrome88) */
a.btn {
color: #333;
}
a.btn:hover {
color: #444;
}
a.btn:active {
color: #555;
}
```
More complex cases may generate the `:is()` pseudo-class:
```css
/* Original input */
div, p {
.warning, .error {
padding: 20px;
}
}
/* New output (with --target=chrome88) */
:is(div, p) :is(.warning, .error) {
padding: 20px;
}
```
In addition, esbuild now has a special warning message for nested style rules that start with an identifier. This isn't allowed in CSS because the syntax would be ambiguous with the existing declaration syntax. The new warning message looks like this:
▲ [WARNING] A nested style rule cannot start with "p" because it looks like the start of a declaration [css-syntax-error]
:1:7:
1 │ main { p { margin: auto } }
│ ^
╵ :is(p)
To start a nested style rule with an identifier, you need to wrap the identifier in ":is(...)" to
prevent the rule from being parsed as a declaration.
Keep in mind that the transformation in this release is a preliminary implementation. CSS has many features that interact in complex ways, and there may be some edge cases that don't work correctly yet.
- Minification now removes unnecessary `&` CSS nesting selectors
This release introduces the following CSS minification optimizations:
```css
/* Original input */
a {
font-weight: bold;
& {
color: blue;
}
& :hover {
text-decoration: underline;
}
}
/* Old output (with --minify) */
a{font-weight:700;&{color:#00f}& :hover{text-decoration:underline}}
/* New output (with --minify) */
a{font-weight:700;:hover{text-decoration:underline}color:#00f}
```
- Minification now removes duplicates from CSS selector lists
This release introduces the following CSS minification optimization:
```css
/* Original input */
div, div { color: red }
/* Old output (with --minify) */
div,div{color:red}
/* New output (with --minify) */
div{color:red}
```
### [`v0.17.13`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01713)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.12...v0.17.13)
- Work around an issue with `NODE_PATH` and Go's WebAssembly internals ([#3001](https://togithub.com/evanw/esbuild/issues/3001))
Go's WebAssembly implementation returns `EINVAL` instead of `ENOTDIR` when using the `readdir` syscall on a file. This messes up esbuild's implementation of node's module resolution algorithm since encountering `ENOTDIR` causes esbuild to continue its search (since it's a normal condition) while other encountering other errors causes esbuild to fail with an I/O error (since it's an unexpected condition). You can encounter this issue in practice if you use node's legacy `NODE_PATH` feature to tell esbuild to resolve node modules in a custom directory that was not installed by npm. This release works around this problem by converting `EINVAL` into `ENOTDIR` for the `readdir` syscall.
- Fix a minification bug with CSS `@layer` rules that have parsing errors ([#3016](https://togithub.com/evanw/esbuild/issues/3016))
CSS at-rules [require either a `{}` block or a semicolon at the end](https://www.w3.org/TR/css-syntax-3/#consume-at-rule). Omitting both of these causes esbuild to treat the rule as an unknown at-rule. Previous releases of esbuild had a bug that incorrectly removed unknown at-rules without any children during minification if the at-rule token matched an at-rule that esbuild can handle. Specifically [cssnano](https://cssnano.co/) can generate `@layer` rules with parsing errors, and empty `@layer` rules cannot be removed because they have side effects (`@layer` didn't exist when esbuild's CSS support was added, so esbuild wasn't written to handle this). This release changes esbuild to no longer discard `@layer` rules with parsing errors when minifying (the rule `@layer c` has a parsing error):
```css
/* Original input */
@layer a {
@layer b {
@layer c
}
}
/* Old output (with --minify) */
@layer a.b;
/* New output (with --minify) */
@layer a.b.c;
```
- Unterminated strings in CSS are no longer an error
The CSS specification provides [rules for handling parsing errors](https://www.w3.org/TR/CSS22/syndata.html#parsing-errors). One of those rules is that user agents must close strings upon reaching the end of a line (i.e., before an unescaped line feed, carriage return or form feed character), but then drop the construct (declaration or rule) in which the string was found. For example:
```css
p {
color: green;
font-family: 'Courier New Times
color: red;
color: green;
}
```
...would be treated the same as:
```css
p { color: green; color: green; }
```
...because the second declaration (from `font-family` to the semicolon after `color: red`) is invalid and is dropped.
Previously using this CSS with esbuild failed to build due to a syntax error, even though the code can be interpreted by a browser. With this release, the code now produces a warning instead of an error, and esbuild prints the invalid CSS such that it stays invalid in the output:
```css
/* esbuild's new non-minified output: */
p {
color: green;
font-family: 'Courier New Times
color: red;
color: green;
}
```
```css
/* esbuild's new minified output: */
p{font-family:'Courier New Times
color: red;color:green}
```
### [`v0.17.12`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01712)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.11...v0.17.12)
- Fix a crash when parsing inline TypeScript decorators ([#2991](https://togithub.com/evanw/esbuild/issues/2991))
Previously esbuild's TypeScript parser crashed when parsing TypeScript decorators if the definition of the decorator was inlined into the decorator itself:
```ts
@(function sealed(constructor: Function) {
Object.seal(constructor);
Object.seal(constructor.prototype);
})
class Foo {}
```
This crash was not noticed earlier because this edge case did not have test coverage. The crash is fixed in this release.
### [`v0.17.11`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01711)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.10...v0.17.11)
- Fix the `alias` feature to always prefer the longest match ([#2963](https://togithub.com/evanw/esbuild/issues/2963))
It's possible to configure conflicting aliases such as `--alias:a=b` and `--alias:a/c=d`, which is ambiguous for the import path `a/c/x` (since it could map to either `b/c/x` or `d/x`). Previously esbuild would pick the first matching `alias`, which would non-deterministically pick between one of the possible matches. This release fixes esbuild to always deterministically pick the longest possible match.
- Minify calls to some global primitive constructors ([#2962](https://togithub.com/evanw/esbuild/issues/2962))
With this release, esbuild's minifier now replaces calls to `Boolean`/`Number`/`String`/`BigInt` with equivalent shorter code when relevant:
```js
// Original code
console.log(
Boolean(a ? (b | c) !== 0 : (c & d) !== 0),
Number(e ? '1' : '2'),
String(e ? '1' : '2'),
BigInt(e ? 1n : 2n),
)
// Old output (with --minify)
console.log(Boolean(a?(b|c)!==0:(c&d)!==0),Number(e?"1":"2"),String(e?"1":"2"),BigInt(e?1n:2n));
// New output (with --minify)
console.log(!!(a?b|c:c&d),+(e?"1":"2"),e?"1":"2",e?1n:2n);
```
- Adjust some feature compatibility tables for node ([#2940](https://togithub.com/evanw/esbuild/issues/2940))
This release makes the following adjustments to esbuild's internal feature compatibility tables for node, which tell esbuild which versions of node are known to support all aspects of that feature:
- `class-private-brand-checks`: node v16.9+ => node v16.4+ (a decrease)
- `hashbang`: node v12.0+ => node v12.5+ (an increase)
- `optional-chain`: node v16.9+ => node v16.1+ (a decrease)
- `template-literal`: node v4+ => node v10+ (an increase)
Each of these adjustments was identified by comparing against data from the `node-compat-table` package and was manually verified using old node executables downloaded from https://nodejs.org/download/release/.
### [`v0.17.10`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#01710)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.9...v0.17.10)
- Update esbuild's handling of CSS nesting to match the latest specification changes ([#1945](https://togithub.com/evanw/esbuild/issues/1945))
The syntax for the upcoming CSS nesting feature has [recently changed](https://webkit.org/blog/13813/try-css-nesting-today-in-safari-technology-preview/). The `@nest` prefix that was previously required in some cases is now gone, and nested rules no longer have to start with `&` (as long as they don't start with an identifier or function token).
This release updates esbuild's pass-through handling of CSS nesting syntax to match the latest specification changes. So you can now use esbuild to bundle CSS containing nested rules and try them out in a browser that supports CSS nesting (which includes nightly builds of both Chrome and Safari).
However, I'm not implementing lowering of nested CSS to non-nested CSS for older browsers yet. While the syntax has been decided, the semantics are still in flux. In particular, there is still some debate about changing the fundamental way that CSS nesting works. For example, you might think that the following CSS is equivalent to a `.outer .inner button { ... }` rule:
```css
.inner button {
.outer & {
color: red;
}
}
```
But instead it's actually equivalent to a `.outer :is(.inner button) { ... }` rule which unintuitively also matches the following DOM structure:
```html
```
The `:is()` behavior is preferred by browser implementers because it's more memory-efficient, but the straightforward translation into a `.outer .inner button { ... }` rule is preferred by developers used to the existing CSS preprocessing ecosystem (e.g. SASS). It seems premature to commit esbuild to specific semantics for this syntax at this time given the ongoing debate.
- Fix cross-file CSS rule deduplication involving `url()` tokens ([#2936](https://togithub.com/evanw/esbuild/issues/2936))
Previously cross-file CSS rule deduplication didn't handle `url()` tokens correctly. These tokens contain references to import paths which may be internal (i.e. in the bundle) or external (i.e. not in the bundle). When comparing two `url()` tokens for equality, the underlying import paths should be compared instead of their references. This release of esbuild fixes `url()` token comparisons. One side effect is that `@font-face` rules should now be deduplicated correctly across files:
```css
/* Original code */
@import "data:text/css, \
@import 'http://example.com/style.css'; \
@font-face { src: url(http://example.com/font.ttf) }";
@import "data:text/css, \
@font-face { src: url(http://example.com/font.ttf) }";
/* Old output (with --bundle --minify) */
@import"http://example.com/style.css";@font-face{src:url(http://example.com/font.ttf)}@font-face{src:url(http://example.com/font.ttf)}
/* New output (with --bundle --minify) */
@import"http://example.com/style.css";@font-face{src:url(http://example.com/font.ttf)}
```
### [`v0.17.9`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#0179)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.8...v0.17.9)
- Parse rest bindings in TypeScript types ([#2937](https://togithub.com/evanw/esbuild/issues/2937))
Previously esbuild was unable to parse the following valid TypeScript code:
```ts
let tuple: (...[e1, e2, ...es]: any) => any
```
This release includes support for parsing code like this.
- Fix TypeScript code translation for certain computed `declare` class fields ([#2914](https://togithub.com/evanw/esbuild/issues/2914))
In TypeScript, the key of a computed `declare` class field should only be preserved if there are no decorators for that field. Previously esbuild always preserved the key, but esbuild will now remove the key to match the output of the TypeScript compiler:
```ts
// Original code
declare function dec(a: any, b: any): any
declare const removeMe: unique symbol
declare const keepMe: unique symbol
class X {
declare [removeMe]: any
@dec declare [keepMe]: any
}
// Old output
var _a;
class X {
}
removeMe, _a = keepMe;
__decorateClass([
dec
], X.prototype, _a, 2);
// New output
var _a;
class X {
}
_a = keepMe;
__decorateClass([
dec
], X.prototype, _a, 2);
```
- Fix a crash with path resolution error generation ([#2913](https://togithub.com/evanw/esbuild/issues/2913))
In certain situations, a module containing an invalid import path could previously cause esbuild to crash when it attempts to generate a more helpful error message. This crash has been fixed.
### [`v0.17.8`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#0178)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.7...v0.17.8)
- Fix a minification bug with non-ASCII identifiers ([#2910](https://togithub.com/evanw/esbuild/issues/2910))
This release fixes a bug with esbuild where non-ASCII identifiers followed by a keyword were incorrectly not separated by a space. This bug affected both the `in` and `instanceof` keywords. Here's an example of the fix:
```js
// Original code
π in a
// Old output (with --minify --charset=utf8)
πin a;
// New output (with --minify --charset=utf8)
π in a;
```
- Fix a regression with esbuild's WebAssembly API in version 0.17.6 ([#2911](https://togithub.com/evanw/esbuild/issues/2911))
Version 0.17.6 of esbuild updated the Go toolchain to version 1.20.0. This had the unfortunate side effect of increasing the amount of stack space that esbuild uses (presumably due to some changes to Go's WebAssembly implementation) which could cause esbuild's WebAssembly-based API to crash with a stack overflow in cases where it previously didn't crash. One such case is the package `grapheme-splitter` which contains code that looks like this:
```js
if (
(0x0300 <= code && code <= 0x036F) ||
(0x0483 <= code && code <= 0x0487) ||
(0x0488 <= code && code <= 0x0489) ||
(0x0591 <= code && code <= 0x05BD) ||
// ... many hundreds of lines later ...
) {
return;
}
```
This edge case involves a chain of binary operators that results in an AST over 400 nodes deep. Normally this wouldn't be a problem because Go has growable call stacks, so the call stack would just grow to be as large as needed. However, WebAssembly byte code deliberately doesn't expose the ability to manipulate the stack pointer, so Go's WebAssembly translation is forced to use the fixed-size WebAssembly call stack. So esbuild's WebAssembly implementation is vulnerable to stack overflow in cases like these.
It's not unreasonable for this to cause a stack overflow, and for esbuild's answer to this problem to be "don't write code like this." That's how many other AST-manipulation tools handle this problem. However, it's possible to implement AST traversal using iteration instead of recursion to work around limited call stack space. This version of esbuild implements this code transformation for esbuild's JavaScript parser and printer, so esbuild's WebAssembly implementation is now able to process the `grapheme-splitter` package (at least when compiled with Go 1.20.0 and run with node's WebAssembly implementation).
### [`v0.17.7`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#0177)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.6...v0.17.7)
- Change esbuild's parsing of TypeScript instantiation expressions to match TypeScript 4.8+ ([#2907](https://togithub.com/evanw/esbuild/issues/2907))
This release updates esbuild's implementation of instantiation expression erasure to match [microsoft/TypeScript#49353](https://togithub.com/microsoft/TypeScript/pull/49353). The new rules are as follows (copied from TypeScript's PR description):
> When a potential type argument list is followed by
>
> - a line break,
> - an `(` token,
> - a template literal string, or
> - any token except `<` or `>` that isn't the start of an expression,
>
> we consider that construct to be a type argument list. Otherwise we consider the construct to be a `<` relational expression followed by a `>` relational expression.
- Ignore `sideEffects: false` for imported CSS files ([#1370](https://togithub.com/evanw/esbuild/issues/1370), [#1458](https://togithub.com/evanw/esbuild/pull/1458), [#2905](https://togithub.com/evanw/esbuild/issues/2905))
This release ignores the `sideEffects` annotation in `package.json` for CSS files that are imported into JS files using esbuild's `css` loader. This means that these CSS files are no longer be tree-shaken.
Importing CSS into JS causes esbuild to automatically create a CSS entry point next to the JS entry point containing the bundled CSS. Previously packages that specified some form of `"sideEffects": false` could potentially cause esbuild to consider one or more of the JS files on the import path to the CSS file to be side-effect free, which would result in esbuild removing that CSS file from the bundle. This was problematic because the removal of that CSS is outwardly observable, since all CSS is global, so it was incorrect for previous versions of esbuild to tree-shake CSS files imported into JS files.
- Add constant folding for certain additional equality cases ([#2394](https://togithub.com/evanw/esbuild/issues/2394), [#2895](https://togithub.com/evanw/esbuild/issues/2895))
This release adds constant folding for expressions similar to the following:
```js
// Original input
console.log(
null === 'foo',
null === undefined,
null == undefined,
false === 0,
false == 0,
1 === true,
1 == true,
)
// Old output
console.log(
null === "foo",
null === void 0,
null == void 0,
false === 0,
false == 0,
1 === true,
1 == true
);
// New output
console.log(
false,
false,
true,
false,
true,
false,
true
);
```
### [`v0.17.6`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#0176)
[Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.5...v0.17.6)
- Fix a CSS parser crash on invalid CSS ([#2892](https://togithub.com/evanw/esbuild/issues/2892))
Previously the following invalid CSS caused esbuild's parser to crash:
```css
@media screen
```
The crash was caused by trying to construct a helpful error message assuming that there was an opening `{` token, which is not the case here. This release fixes the crash.
- Inline TypeScript enums that are referenced before their declaration
Previously esbuild inlined enums within a TypeScript file from top to bottom, which meant that references to TypeScript enum members were only inlined within the same file if they came after the enum declaration. With this release, esbuild will now inline enums even when they are referenced before they are declared:
```ts
// Original input
export const foo = () => Foo.FOO
const enum Foo { FOO = 0 }
// Old output (with --tree-shaking=true)
export const foo = () => Foo.FOO;
var Foo = /* @__PURE__ */ ((Foo2) => {
Foo2[Foo2["FOO"] = 0] = "FOO";
return Foo2;
})(Foo || {});
// New output (with --tree-shaking=true)
export c
Configuration
📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).
🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.
♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
[ ] If you want to rebase/retry this PR, check this box
This PR has been generated by Mend Renovate. View repository job log here.
This PR contains the following updates:
^0.17.0->^0.18.0Release Notes
evanw/esbuild
### [`v0.18.0`](https://togithub.com/evanw/esbuild/blob/HEAD/CHANGELOG.md#0180) [Compare Source](https://togithub.com/evanw/esbuild/compare/v0.17.19...v0.18.0) **This release deliberately contains backwards-incompatible changes.** To avoid automatically picking up releases like this, you should either be pinning the exact version of `esbuild` in your `package.json` file (recommended) or be using a version range syntax that only accepts patch upgrades such as `^0.17.0` or `~0.17.0`. See npm's documentation about [semver](https://docs.npmjs.com/cli/v6/using-npm/semver/) for more information. The breaking changes in this release mainly focus on fixing some long-standing issues with esbuild's handling of `tsconfig.json` files. Here are all the changes in this release, in detail: - Add a way to try esbuild online ([#797](https://togithub.com/evanw/esbuild/issues/797)) There is now a way to try esbuild live on esbuild's website without installing it: https://esbuild.github.io/try/. In addition to being able to more easily evaluate esbuild, this should also make it more efficient to generate esbuild bug reports. For example, you can use it to compare the behavior of different versions of esbuild on the same input. The state of the page is stored in the URL for easy sharing. Many thanks to [@hyrious](https://togithub.com/hyrious) for creating https://hyrious.me/esbuild-repl/, which was the main inspiration for this addition to esbuild's website. Two forms of build options are supported: either CLI-style ([example](https://esbuild.github.io/try/#dAAwLjE3LjE5AC0tbG9hZGVyPXRzeCAtLW1pbmlmeSAtLXNvdXJjZW1hcABsZXQgZWw6IEpTWC5FbGVtZW50ID0gPGRpdiAvPg)) or JS-style ([example](https://esbuild.github.io/try/#dAAwLjE3LjE5AHsKICBsb2FkZXI6ICd0c3gnLAogIG1pbmlmeTogdHJ1ZSwKICBzb3VyY2VtYXA6IHRydWUsCn0AbGV0IGVsOiBKU1guRWxlbWVudCA9IDxkaXYgLz4)). Both are converted into a JS object that's passed to esbuild's WebAssembly API. The CLI-style argument parser is a custom one that simulates shell quoting rules, and the JS-style argument parser is also custom and parses a superset of JSON (basically JSON5 + regular expressions). So argument parsing is an approximate simulation of what happens for real but hopefully it should be close enough. - Changes to esbuild's `tsconfig.json` support ([#3019](https://togithub.com/evanw/esbuild/issues/3019)): This release makes the following changes to esbuild's `tsconfig.json` support: - Using experimental decorators now requires `"experimentalDecorators": true` ([#104](https://togithub.com/evanw/esbuild/issues/104)) Previously esbuild would always compile decorators in TypeScript code using TypeScript's experimental decorator transform. Now that standard JavaScript decorators are close to being finalized, esbuild will now require you to use `"experimentalDecorators": true` to do this. This new requirement makes it possible for esbuild to introduce a transform for standard JavaScript decorators in TypeScript code in the future. Such a transform has not been implemented yet, however. - TypeScript's `target` no longer affects esbuild's `target` ([#2628](https://togithub.com/evanw/esbuild/issues/2628)) Some people requested that esbuild support TypeScript's `target` setting, so support for it was added (in [version 0.12.4](https://togithub.com/evanw/esbuild/releases/v0.12.4)). However, esbuild supports reading from multiple `tsconfig.json` files within a single build, which opens up the possibility that different files in the build have different language targets configured. There isn't really any reason to do this and it can lead to unexpected results. So with this release, the `target` setting in `tsconfig.json` will no longer affect esbuild's own `target` setting. You will have to use esbuild's own target setting instead (which is a single, global value). - TypeScript's `jsx` setting no longer causes esbuild to preserve JSX syntax ([#2634](https://togithub.com/evanw/esbuild/issues/2634)) TypeScript has a setting called [`jsx`](https://www.typescriptlang.org/tsconfig#jsx) that controls how to transform JSX into JS. The tool-agnostic transform is called `react`, and the React-specific transform is called `react-jsx` (or `react-jsxdev`). There is also a setting called `preserve` which indicates JSX should be passed through untransformed. Previously people would run esbuild with `"jsx": "preserve"` in their `tsconfig.json` files and then be surprised when esbuild preserved their JSX. So with this release, esbuild will now ignore `"jsx": "preserve"` in `tsconfig.json` files. If you want to preserve JSX syntax with esbuild, you now have to use `--jsx=preserve`. Note: Some people have suggested that esbuild's equivalent `jsx` setting override the one in `tsconfig.json`. However, some projects need to legitimately have different files within the same build use different transforms (i.e. `react` vs. `react-jsx`) and having esbuild's global `jsx` setting override `tsconfig.json` would prevent this from working. This release ignores `"jsx": "preserve"` but still allows other `jsx` values in `tsconfig.json` files to override esbuild's global `jsx` setting to keep the ability for multiple files within the same build to use different transforms. - `useDefineForClassFields` behavior has changed ([#2584](https://togithub.com/evanw/esbuild/issues/2584), [#2993](https://togithub.com/evanw/esbuild/issues/2993)) Class fields in TypeScript look like this (`x` is a class field): ```js class Foo { x = 123 } ``` TypeScript has legacy behavior that uses assignment semantics instead of define semantics for class fields when [`useDefineForClassFields`](https://www.typescriptlang.org/tsconfig#useDefineForClassFields) is enabled (in which case class fields in TypeScript behave differently than they do in JavaScript, which is arguably "wrong"). This legacy behavior exists because TypeScript added class fields to TypeScript before they were added to JavaScript. The TypeScript team decided to go with assignment semantics and shipped their implementation. Much later on TC39 decided to go with define semantics for class fields in JavaScript instead. This behaves differently if the base class has a setter with the same name: ```js class Base { set x(_) { console.log('x:', _) } } // useDefineForClassFields: false class AssignSemantics extends Base { constructor() { super() this.x = 123 } } // useDefineForClassFields: true class DefineSemantics extends Base { constructor() { super() Object.defineProperty(this, 'x', { value: 123 }) } } console.log( new AssignSemantics().x, // Calls the setter new DefineSemantics().x // Doesn't call the setter ) ``` When you run `tsc`, the value of `useDefineForClassFields` defaults to `false` when it's not specified and the `target` in `tsconfig.json` is present but earlier than `ES2022`. This sort of makes sense because the class field language feature was added in ES2022, so before ES2022 class fields didn't exist (and thus TypeScript's legacy behavior is active). However, TypeScript's `target` setting currently defaults to `ES3` which unfortunately means that the `useDefineForClassFields` setting currently defaults to false (i.e. to "wrong"). In other words if you run `tsc` with all default settings, class fields will behave incorrectly. Previously esbuild tried to do what `tsc` did. That meant esbuild's version of `useDefineForClassFields` was `false` by default, and was also `false` if esbuild's `--target=` was present but earlier than `es2022`. However, TypeScript's legacy class field behavior is becoming increasingly irrelevant and people who expect class fields in TypeScript to work like they do in JavaScript are confused when they use esbuild with default settings. It's also confusing that the behavior of class fields would change if you changed the language target (even though that's exactly how TypeScript works). So with this release, esbuild will now only use the information in `tsconfig.json` to determine whether `useDefineForClassFields` is true or not. Specifically `useDefineForClassFields` will be respected if present, otherwise it will be `false` if `target` is present in `tsconfig.json` and is `ES2021` or earlier, otherwise it will be `true`. Targets passed to esbuild's `--target=` setting will no longer affect `useDefineForClassFields`. Note that this means different directories in your build can have different values for this setting since esbuild allows different directories to have different `tsconfig.json` files within the same build. This should let you migrate your code one directory at a time without esbuild's `--target=` setting affecting the semantics of your code. - Add support for `verbatimModuleSyntax` from TypeScript 5.0 TypeScript 5.0 added a new option called [`verbatimModuleSyntax`](https://www.typescriptlang.org/tsconfig#verbatimModuleSyntax) that deprecates and replaces two older options, `preserveValueImports` and `importsNotUsedAsValues`. Setting `verbatimModuleSyntax` to true in `tsconfig.json` tells esbuild to not drop unused import statements. Specifically esbuild now treats `"verbatimModuleSyntax": true` as if you had specified both `"preserveValueImports": true` and `"importsNotUsedAsValues": "preserve"`. - Add multiple inheritance for `tsconfig.json` from TypeScript 5.0 TypeScript 5.0 now allows [multiple inheritance for `tsconfig.json` files](https://devblogs.microsoft.com/typescript/announcing-typescript-5-0/#supporting-multiple-configuration-files-in-extends). You can now pass an array of filenames via the `extends` parameter and your `tsconfig.json` will start off containing properties from all of those configuration files, in order. This release of esbuild adds support for this new TypeScript feature. - Remove support for `moduleSuffixes` ([#2395](https://togithub.com/evanw/esbuild/issues/2395)) The community has requested that esbuild remove support for TypeScript's `moduleSuffixes` feature, so it has been removed in this release. Instead you can use esbuild's `--resolve-extensions=` feature to select which module suffix you want to build with. - Apply `--tsconfig=` overrides to `stdin` and virtual files ([#385](https://togithub.com/evanw/esbuild/issues/385), [#2543](https://togithub.com/evanw/esbuild/issues/2543)) When you override esbuild's automatic `tsconfig.json` file detection with `--tsconfig=` to pass a specific `tsconfig.json` file, esbuild previously didn't apply these settings to source code passed via the `stdin` API option or to TypeScript files from plugins that weren't in the `file` namespace. This release changes esbuild's behavior so that settings from `tsconfig.json` also apply to these source code files as well. - Support `--tsconfig-raw=` in build API calls ([#943](https://togithub.com/evanw/esbuild/issues/943), [#2440](https://togithub.com/evanw/esbuild/issues/2440)) Previously if you wanted to override esbuild's automatic `tsconfig.json` file detection, you had to create a new `tsconfig.json` file and pass the file name to esbuild via the `--tsconfig=` flag. With this release, you can now optionally use `--tsconfig-raw=` instead to pass the contents of `tsconfig.json` to esbuild directly instead of passing the file name. For example, you can now use `--tsconfig-raw={"compilerOptions":{"experimentalDecorators":true}}` to enable TypeScript experimental decorators directly using a command-line flag (assuming you escape the quotes correctly using your current shell's quoting rules). The `--tsconfig-raw=` flag previously only worked with transform API calls but with this release, it now works with build API calls too. - Ignore all `tsconfig.json` files in `node_modules` ([#276](https://togithub.com/evanw/esbuild/issues/276), [#2386](https://togithub.com/evanw/esbuild/issues/2386)) This changes esbuild's behavior that applies `tsconfig.json` to all files in the subtree of the directory containing `tsconfig.json`. In version 0.12.7, esbuild started ignoring `tsconfig.json` files inside `node_modules` folders. The rationale is that people typically do this by mistake and that doing this intentionally is a rare use case that doesn't need to be supported. However, this change only applied to certain syntax-specific settings (e.g. `jsxFactory`) but did not apply to path resolution settings (e.g. `paths`). With this release, esbuild will now ignore all `tsconfig.json` files in `node_modules` instead of only ignoring certain settings. - Ignore `tsconfig.json` when resolving paths within `node_modules` ([#2481](https://togithub.com/evanw/esbuild/issues/2481)) Previously fields in `tsconfig.json` related to path resolution (e.g. `paths`) were respected for all files in the subtree containing that `tsconfig.json` file, even within a nested `node_modules` subdirectory. This meant that a project's `paths` settings could potentially affect any bundled packages. With this release, esbuild will no longer use `tsconfig.json` settings during path resolution inside nested `node_modules` subdirectories. - Prefer `.js` over `.ts` within `node_modules` ([#3019](https://togithub.com/evanw/esbuild/issues/3019)) The default list of implicit extensions that esbuild will try appending to import paths contains `.ts` before `.js`. This makes it possible to bundle TypeScript projects that reference other files in the project using extension-less imports (e.g. `./some-file` to load `./some-file.ts` instead of `./some-file.js`). However, this behavior is undesirable within `node_modules` directories. Some package authors publish both their original TypeScript code and their compiled JavaScript code side-by-side. In these cases, esbuild should arguably be using the compiled JavaScript files instead of the original TypeScript files because the TypeScript compilation settings for files within the package should be determined by the package author, not the user of esbuild. So with this release, esbuild will now prefer implicit `.js` extensions over `.ts` when searching for import paths within `node_modules`. These changes are intended to improve esbuild's compatibility with `tsc` and reduce the number of unfortunate behaviors regarding `tsconfig.json` and esbuild. - Add a workaround for bugs in Safari 16.2 and earlier ([#3072](https://togithub.com/evanw/esbuild/issues/3072)) Safari's JavaScript parser had a bug (which has now been fixed) where at least something about unary/binary operators nested inside default arguments nested inside either a function or class expression was incorrectly considered a syntax error if that expression was the target of a property assignment. Here are some examples that trigger this Safari bug: ❱ x(function (y = -1) {}.z = 2) SyntaxError: Left hand side of operator '=' must be a reference. ❱ x(class { f(y = -1) {} }.z = 2) SyntaxError: Left hand side of operator '=' must be a reference. It's not clear what the exact conditions are that trigger this bug. However, a workaround for this bug appears to be to post-process your JavaScript to wrap any in function and class declarations that are the direct target of a property access expression in parentheses. That's the workaround that UglifyJS applies for this issue: [mishoo/UglifyJS#2056](https://togithub.com/mishoo/UglifyJS/pull/2056). So that's what esbuild now does starting with this release: ```js // Original code x(function (y = -1) {}.z = 2, class { f(y = -1) {} }.z = 2) // Old output (with --minify --target=safari16.2) x(function(c=-1){}.z=2,class{f(c=-1){}}.z=2); // New output (with --minify --target=safari16.2) x((function(c=-1){}).z=2,(class{f(c=-1){}}).z=2); ``` This fix is not enabled by default. It's only enabled when `--target=` contains Safari 16.2 or earlier, such as with `--target=safari16.2`. You can also explicitly enable or disable this specific transform (called `function-or-class-property-access`) with `--supported:function-or-class-property-access=false`. - Fix esbuild's TypeScript type declarations to forbid unknown properties ([#3089](https://togithub.com/evanw/esbuild/issues/3089)) Version 0.17.0 of esbuild introduced a specific form of function overloads in the TypeScript type definitions for esbuild's API calls that looks like this: ```ts interface TransformOptions { legalComments?: 'none' | 'inline' | 'eof' | 'external' } interface TransformResultConfiguration
📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).
🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.
♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
This PR has been generated by Mend Renovate. View repository job log here.