Cannot read property 'filter' of undefined

[RikuVan]

I am getting this error (trace below). I thought this was perhaps due to using the typescript parser but it seems to occur even if I remove the parser. Any suggestions would be much appreciated about how to proceed/ debug the issue.

eslintrc:

{
  "parser": "@typescript-eslint/parser",
  "plugins": ["svelte3", "@typescript-eslint"],
  "extends": "standard",
  "parserOptions": {
    "extraFileExtensions": [".svelte"]
  },
  "rules": {
    "semis": 0,
    "space-before-function-paren": 0,
    "no-console": "off"
  }
}

TypeError: Cannot read property 'filter' of undefined
    at preprocess (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint-plugin-svelte3/index.js:157:30)
    at Linter.verify (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/linter.js:954:13)
    at Linter.verify (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint-plugin-svelte3/index.js:303:17)
    at Linter.verifyAndFix (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/linter.js:1047:29)
    at processText (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:197:32)
    at processFile (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:241:12)
    at fileList.map.fileInfo (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:616:40)
    at Array.map (<anonymous>)
    at CLIEngine.executeOnFiles (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:588:34)
    at Object.execute (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli.js:205:111)
error Command failed with exit code 2.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
➜  svelte-ts-starter git:(master) ✗ yarn run lint
yarn run v1.13.0
$ eslint src/**/*.ts src/**/*.svelte
<script>
  export let src =
    'https://images.pexels.com/photos/356378/pexels-photo-356378.jpeg?auto=compress&cs=tinysrgb&dpr=2&w=500'
  export let alt = 'white-dog'
</script>

<img
  src="https://images.pexels.com/photos/356378/pexels-photo-356378.jpeg?auto=compress&cs=tinysrgb&dpr=2&w=500"
  alt="hey"
/>

TypeError: Cannot read property 'filter' of undefined
    at preprocess (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint-plugin-svelte3/index.js:157:30)
    at Linter.verify (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/linter.js:954:13)
    at Linter.verify (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint-plugin-svelte3/index.js:303:17)
    at Linter.verifyAndFix (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/linter.js:1047:29)
    at processText (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:197:32)
    at processFile (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:241:12)
    at fileList.map.fileInfo (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:616:40)
    at Array.map (<anonymous>)
    at CLIEngine.executeOnFiles (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli-engine.js:588:34)
    at Object.execute (/Users/richard.vancamp/Code/Repos/svelte-ts-starter/node_modules/eslint/lib/cli.js:205:111)

[RikuVan]

By the way, it would be super helpful if you could provide an example of how the options, like ignoring styles, are actually used with the .eslintrc.

[Conduitry]

I can't reproduce this. I have a package.json containing:

{
  "dependencies": {
    "@typescript-eslint/eslint-plugin": "^1.7.0",
    "@typescript-eslint/parser": "^1.7.0",
    "eslint": "^5.16.0",
    "eslint-config-standard": "^12.0.0",
    "eslint-plugin-import": "^2.17.2",
    "eslint-plugin-node": "^8.0.1",
    "eslint-plugin-promise": "^4.1.1",
    "eslint-plugin-standard": "^4.0.0",
    "eslint-plugin-svelte3": "^1.0.0",
    "svelte": "^3.1.0",
    "typescript": "^3.4.5"
  }
}

a .eslintrc containining:

{
  "root": true,
  "parser": "@typescript-eslint/parser",
  "plugins": ["svelte3", "@typescript-eslint"],
  "extends": "standard",
  "parserOptions": {
    "extraFileExtensions": [".svelte"]
  },
  "rules": {
    "semis": 0,
    "space-before-function-paren": 0,
    "no-console": "off"
  }
}

and a test.svelte containing:

<script>
  export let src =
    'https://images.pexels.com/photos/356378/pexels-photo-356378.jpeg?auto=compress&cs=tinysrgb&dpr=2&w=500'
  export let alt = 'white-dog'
</script>

<img
  src="https://images.pexels.com/photos/356378/pexels-photo-356378.jpeg?auto=compress&cs=tinysrgb&dpr=2&w=500"
  alt="hey"
/>

and when I run ./node_modules/.bin/eslint test.svelte I get no errors. If I edit the file to introduce a linting error (e.g., adding a semicolon), I do see that error.

Do you have a repo where I can reproduce this issue?

[RikuVan]

https://github.com/RikuVan/svelte3-ts-starter

[RikuVan]

I can try later to put the code on online somewhere, e.g. codesandbox or glitch.

[Conduitry]

When I clone that project, install dependencies, and run the lint script I get:

/.../svelte3-ts-starter/src/components/Image.svelte
  2:2  error  Parsing error: Expression expected

✖ 1 problem (1 error, 0 warnings)

[RikuVan]

sorry that was probably was slightly different than the version I had locally, which I now pushed--namely the linting was removed.

[RikuVan]

Anyways, if you don't get a similar issue, then I should do something in Glitch so we know it is not some other environment issue. node v11.10.0 by the way.

[Conduitry]

Okay, thanks, yep I am seeing the same exception as you are now.

[Conduitry]

https://github.com/RikuVan/svelte3-ts-starter/blob/master/yarn.lock#L2710 You're running Svelte 3 beta 3. Beta 4 introduced some changes to the output of the compiler that this plugin needs. You need to upgrade to a newer version, preferably one of the official non-beta releases from this past week.

[RikuVan]

oh no, sorry to trouble you with old version. Works now of course.