PhET Code-Review Checklist (a.k.a "CRC")

~ Mark failed items with ❌ and note any related GitHub issues.~ ~ Call attention to items with ⚠️ and note any related GitHub issues.~ ~* Mark items that are not applicable with N/A~

UPDATE from @samreid, it will be more efficient for this code review for me to open a side issue for failed items, and to check off something that has been reviewed (even if it revealed a problem). I have also employed the new GitHub feature to convert checkboxes to issues.

Specific Instructions

Provide specific instructions here. For example: known problems that will fail CRC items, files that can be skipped, code that is not completed, shared or common code that also needs to be reviewed,... If there are no specific instructions, then delete this section.

GitHub Issues

The following standard GitHub issues should exist. If these issues are missing, or have not been completed, pause code review until the issues have been created and addressed by the responsible dev.

[ ] results of memory testing for brands=phet, see {{GITHUB_ISSUE_LINK}}
[ ] results of memory testing for brands=phet-io (if the sim is instrumented for PhET-iO), see {{GITHUB_ISSUE_LINK}}
[ ] performance testing and sign-off, see {{GITHUB_ISSUE_LINK}}
[ ] review of pointer areas, see {{GITHUB_ISSUE_LINK}}
[ ] credits (will not be completed until after RC testing), see {{GITHUB_ISSUE_LINK}}

## **Build and Run Checks** If any of these items fail, pause code review. - [x] Does the sim build without warnings or errors? - [x] Does the html file size seem reasonable, compared to other similar sims? - [x] Does the sim start up? (unbuilt and built versions) - [x] Does the sim experience any assertion failures? (run with query parameter `ea`) - [x] Does the sim pass a scenery fuzz test? (run with query parameters `fuzz&ea`) - [x] Does the sim behave correctly when listener order is shuffled? (run with query parameters `ea&shuffleListeners` and `ea&shuffleListeners&fuzz`) - [x] Does the sim output any deprecation warnings? Run with `?deprecationWarnings`. Do not use deprecated methods in new code. ## **Memory Leaks** - [x] Does a heap comparison using Chrome Developer Tools indicate a memory leak? (Describing this process is beyond the scope of this document.) Test on a version built using `grunt --minify.mangle=false`. Compare to testing results done by the responsible developer. Results can be found in {{GITHUB_ISSUE_LINK}}. - [x] For each common-code component (sun, scenery-phet, vegas, …) that opaquely registers observers or listeners, is there a call to that component’s `dispose` function, or is it obvious why it isn't necessary, or is there documentation about why `dispose` isn't called? An example of why no call to `dispose` is needed is if the component is used in a `ScreenView` that would never be removed from the scene graph. - [x] #37 * AXON: `Property.link` or `lazyLink` is accompanied by `unlink`. * AXON: `Property.multilink` is accompanied by `unmultilink`. * AXON: Creation of `Multilink` is accompanied by `dispose`. * AXON: Creation of `DerivedProperty` is accompanied by `dispose`. * AXON: `Emitter.addListener` is accompanied by `removeListener`. * AXON: `ObservableArrayDef.element*Emitter.addListener` is accompanied by `ObservableArrayDef.element*Emitter.removeListener` * SCENERY: `Node.addInputListener` is accompanied by `removeInputListener` * TANDEM: Creation of an instrumented `PhetioObject` is accompanied by `dispose`. - [x] Do all types that require a `dispose` function have one? This should expose a public `dispose` function that calls `this.disposeMyType()`, where `disposeMyType` is a private function declared in the constructor. `MyType` should exactly match the filename. ## **Performance** - [x] Play with sim, identify any obvious performance issues. Examples: animation that slows down with large numbers of objects; animation that pauses or "hitches" during garbage collection. - [x] If the sim uses WebGL, does it have a fallback? Does the fallback perform reasonably well? (run with query parameter `webgl=false`) ## **Usability** - [x] Are UI components sufficiently responsive? (especially continuous UI components, such as sliders) - [x] Are pointer areas optimized, especially for touch? (run with query parameter `showPointerAreas`) - [x] Do pointer areas overlap? (run with query parameter `showPointerAreas`) Overlap may be OK in some cases, depending on the z-ordering (if the front-most object is supposed to occlude pointer areas) and whether objects can be moved. ## **Internationalization** - [x] Are there any strings that are not internationalized, and does the sim layout gracefully handle internationalized strings that are shorter than the English strings? (run with query parameter `stringTest=X`. You should see nothing but 'X' strings.) - [x] Does the sim layout gracefully handle internationalized strings that are longer than the English strings? (run with query parameters `stringTest=double` and `stringTest=long`) - [x] Does the sim stay on the sim page (doesn't redirect to an external page) when running with the query parameter `stringTest=xss`? This test passes if sim does not redirect, OK if sim crashes or fails to fully start. Only test on one desktop platform. For PhET-iO sims, additionally test `?stringTest=xss` in Studio to make sure i18n strings didn't leak to phetioDocumentation, see https://github.com/phetsims/phet-io/issues/1377 - [x] Avoid using concatenation to create strings that will be visible in the user interface. Use `StringUtils.fillIn` and a string pattern to ensure that strings are properly localized. - [x] Use named placeholders (e.g. `"{{value}} {{units}}"`) instead of numbered placeholders (e.g. `"{0} {1}"`). - [x] Make sure the string keys are all perfect, because they are difficult to change after 1.0.0 is published. Guidelines for string keys are: (1) Strings keys should generally match their values. E.g.: ```js "helloWorld": { value: "Hello World!" }, "quadraticTerms": { value: "Quadratic Terms" } ``` (2) If a string key would be exceptionally long, use a key name that is an abbreviated form of the string value, or that captures the purpose/essence of the value. E.g.: ```js // key is abbreviated "iWentToTheStore": { value: "I went to the store to get milk, eggs, butter, and sugar." }, // key is based on purpose "describeTheScreen": { value: "The Play Area is a small room. The Control Panel has buttons, a checkbox, and radio buttons to change conditions in the room." } ``` (3) If string key names would collide, use your judgment to disambiguate. E.g.: ```js "simplifyTitle": { value: "Simplify!" }, "simplifyCheckbox": { value: "simplify" } ``` (4) String keys for screen names should have the general form `"screen.{{screenName}}"`. E.g.: ```js "screen.explore": { "value": "Explore" }, ``` (5) String patterns that contain placeholders (e.g. `"My name is {{first}} {{last}}"`) should use keys that are unlikely to conflict with strings that might be needed in the future. For example, for `"{{price}}"` consider using key `"pricePattern"` instead of `"price"`, if you think there might be a future need for a `"price"` string. - [x] If the sim was already released, make sure none of the original string keys have changed. If they have changed, make sure any changes have a good reason and have been discussed with @jbphet (it is likely that an issue like https://github.com/phetsims/gravity-force-lab/issues/166 should be created). ## **Repository Structure** - [x] The repository name should correspond to the sim title. For example, if the sim title is "Wave Interference", then the repository name should be "wave-interference". - [x] Are all required files and directories present? For a sim repository named “my-repo”, the general structure should look like this (where assets/, images/, mipmaps/ or sounds/ may be omitted if the sim doesn’t have those types of resource files). ``` my-repo/ assets/ doc/ images/ *see annotation model.md implementation-notes.md images/ license.json js/ (see section below) mipmaps/ license.json sound/ license.json dependencies.json .gitignore my-repo_en.html my-repo-strings_en.json Gruntfile.js LICENSE package.json README.md ``` *Any images used in model.md or implementation-notes.md should be added here. Images specific to aiding with documentation do not need their own license. - [x] Verify that the same image file is not present in both images/ and mipmaps/. If you need a mipmap, use it for all occurrences of the image. - [x] #41 All JavaScript source should be in the js/ directory. There should be a subdirectory for each screen (this also applies for single-screen sims, where the subdirectory matches the repo name). For a multi-screen sim, code shared by 2 or more screens should be in a js/common/ subdirectory. Model and view code should be in model/ and view/ subdirectories for each screen and common/. For example, for a sim with screens “Introduction” and “Lab”, the general directory structure should look like this: ``` my-repo/ js/ common/ model/ view/ introduction/ model/ view/ lab/ model/ view/ my-repo-main.js myRepo.js myRepoStrings.js ``` - [x] Do filenames use an appropriate prefix? Some filenames may be prefixed with the repository name, e.g. `MolarityConstants.js` in molarity. If the repository name is long, the developer may choose to abbreviate the repository name, e.g. `EEConstants.js` in expression-exchange. If the abbreviation is already used by another respository, then the full name must be used. For example, if the "EE" abbreviation is already used by expression-exchange, then it should not be used in equality-explorer. Whichever convention is used, it should be used consistently within a repository - don't mix abbreviations and full names. - [x] #42 - [x] #43 - [x] #44 - [x] #45 - [x] Does .gitignore match the one in simula-rasa? - [x] In GitHub, verify that all non-release branches have an associated issue that describes their purpose. - [x] Are there any GitHub branches that are no longer needed and should be deleted? - [x] Does `model.md` adequately describe the model, in terms appropriate for teachers? - [x] Does `implementation-notes.md` adequately describe the implementation, with an overview that will be useful to future maintainers? - [x] Sim-specific query parameters (if any) should be identified and documented in one .js file in js/common/ or js/ (if there is no common/). The .js file should be named `{{PREFIX}}QueryParameters.js`, for example ArithmeticQueryParameters.js for the aritmetic repository, or FBQueryParameters.js for Function Builder (where the `FB` prefix is used). - [x] Query parameters that are public-facing should be identified using `public: true` in the schema. - [x] All sims should use a color file named `MyRepoColors.js` or, if using abbreviations, `MRColors.js`, and use `ProfileColorProperty` where appropriate, even if they have a single (default) profile (to support color editing and PhET-iO Studio). The `ColorProfile` pattern was converted to `*Colors.js` files in https://github.com/phetsims/scenery-phet/issues/515. Please see [GasPropertiesColors.js](https://github.com/phetsims/gas-properties/blob/master/js/common/GasPropertiesColors.js) for a good example. ## **Coding Conventions** This section deals with PhET coding conventions. You do not need to exhaustively check every item in this section, nor do you necessarily need to check these items one at a time. The goal is to determine whether the code generally meets PhET standards. - [x] Is the code formatted according to PhET conventions? See [phet-idea-code-style.xml](https://github.com/phetsims/phet-info/blob/master/ide/idea/phet-idea-codestyle.xml) for IntelliJ IDEA code style. - [x] Names (types, variables, properties, Properties, functions,...) should be sufficiently descriptive and specific, and should avoid non-standard abbreviations. For example: ```js const numPart = 100; // incorrect const numberOfParticles = 100; // correct const width = 150; // incorrect const beakerWidth = 150; // correct ``` - [x] Verify that [Best Practices for Modules](https://github.com/phetsims/phet-info/blob/master/doc/best-practices-for-modules.md) are followed. - [x] For constructors, use parameters for things that don’t have a default. Use options for things that have a default value. This improves readability at the call site, especially when the number of parameters is large. It also eliminates order dependency that is required by using parameters. For example, this constructor uses parameters for everything. At the call site, the semantics of the arguments are difficult to determine without consulting the constructor. ```js class BallNode extends Node { /** * @param {Ball} ball - model element * @param {Property.} visibleProperty - is the ball visible? * @param {Color|string} fill - fill color * @param {Color|string} stroke - stroke color * @param {number} lineWidth - width of the stroke */ constructor( ball, visibleProperty, fill, stroke, lineWidth ){ // ... } } // Call site const ballNode = new BallNode( ball, visibleProperty, 'blue', 'black', 2 ); ``` Here’s the same constructor with an appropriate use of options. The call site is easier to read, and the order of options is flexible. ```js class BallNode extends Node { /** * @param {Ball} ball - model element * @param {Property.} visibleProperty - is the ball visible? * @param {Object} [options] */ constructor( ball, visibleProperty, options ) { options = merge( { fill: 'white', // {Color|string} fill color stroke: 'black', // {Color|string} stroke color lineWidth: 1 // {number} width of the stroke }, options ); // ... } } // Call site const ballNode = new BallNode( ball, visibleProperty, { fill: 'blue', stroke: 'black', lineWidth: 2 } ); ``` - [x] When options are passed through one constructor to another, a "nested options" pattern should be used. This helps to avoid duplicating option names and/or accidentally overwriting options for different components that use the same option names. Make sure to use PHET_CORE/merge instead of `_.extend` or `_.merge`. `merge` will automatically recurse to keys named `*Options` and extend those as well. Example: ```js class ParticleBoxNode extends Node { /** * @param {ParticleBox} particleBox - model element * @param {Property.} visibleProperty - are the box and its contents visible? * @param {Object} [options] */ constructor( particleBox, visibleProperty, options ) { options = merge( { fill: 'white', // {Color|string} fill color stroke: 'black', // {Color|string} stroke color lineWidth: 1, // {number} width of the stroke particleNodeOptions: { fill: 'red', stroke: 'gray', lineWidth: 0.5 }, }, options ); // add particle this.addChild( new ParticleNode( particleBox.particle, options.particleNodeOptions ) ); ... } } ``` A possible exception to this guideline is when the constructor API is improved by hiding the implementation details, i.e. not revealing that a sub-component exists. In that case, it may make sense to use new top-level options. This is left to developer and reviewer discretion. For more information on the history and thought process around the "nested options" pattern, please see https://github.com/phetsims/tasks/issues/730. - [x] If references are needed to the enclosing object, such as for a closure, `self` should be defined, but it should only be used in closures. The `self` variable should not be defined unless it is needed in a closure. Example: ```js const self = this; someProperty.link( function(){ self.doSomething(); } ); this.doSomethingElse(); ``` - [x] Generally, lines should not exceed 120 columns. Break up long statements, expressions, or comments into multiple lines to optimize readability. It is OK for require statements or other structured patterns to exceed 120 columns. Use your judgment! - [x] Functions should be invoked using the dot operator rather than the bracket operator. For more details, please see https://github.com/phetsims/gravity-and-orbits/issues/9. For example: ```js // avoid this[ isFaceSmile ? 'smile' : 'frown' ](); // OK isFaceSmile ? this.smile() : this.frown(); // OK if ( isFaceSmile ) { this.smile(); } else { this.frown(); } ``` - [x] It is not uncommon to use conditional shorthand and short circuiting for invocation. Use parentheses to maximize readability. ```js ( expression ) && statement; ( expression ) ? statement1 : statement2; ( foo && bar ) ? fooBar() : fooCat(); ( foo && bar ) && fooBar(); ( foo && !(bar && fooBar)) && nowIAmConfused(); this.fill = ( foo && bar ) ? 'red' : 'blue'; ``` If the expression is only one item, the parentheses can be omitted. This is the most common use case. ```js assert && assert( happy, 'Why aren\'t you happy?' ); happy && smile(); const thoughts = happy ? 'I am happy' : 'I am not happy :('; ``` - [x] Naming for Property values: All `AXON/Property` instances should be declared with the suffix `Property`. For example, if a visible property is added, it should have the name `visibleProperty` instead of simply `visible`. This will help to avoid confusion with non-Property definitions. Identify violations by searching for regular expression "= new .*Property". - [x] #46 - [x] #47 - [x] Files should be named like `CapitalizedCamelCasing.js` when returning a constructor, or `lowerCaseCamelCasing.js` when returning a non-constructor function or singleton. When returning a constructor or singleton, the constructor name should match the filename. - [x] Assertions should be used appropriately and consistently. Type checking should not just be done in code comments. Use `Array.isArray` to type check an array. - [x] If you need to namespace an inner class, use `{{namespace}}.register`, and include a comment about why the inner class needs to be namespaced. Use the form `'{{outerClassname}}.{{innerClassname}}'` for the key. For example: ```js import myNamespace from '...'; class SlotMachineNode extends Node { constructor( ... ) { this.leverNode = new LeverNode(...); ... } ... } myNamespace.register( 'SlotMachineNode', SlotMachineNode ); class LeverNode extends Node { ... } // It was useful to be able to instantiate this in the console for testing, and we may need to do so in the future. myNamespace.register( 'SlotMachineNode.LeverNode', LeverNode ); return SlotMachineNode; ``` - [x] Putting unused parameters in callbacks is up to developer discretion, as long they are correct wrt to the actual callback signature. For example, both of these are acceptable: ```js Property.multilink( [ styleProperty, activeProperty, colorProperty ], ( style, active, color ) => { // some algorithm that uses style and active } ); Property.multilink( [ styleProperty, activeProperty, colorProperty ], ( style, active ) => { // some algorithm that uses style and active } ); ``` This is not acceptable, because the 3rd parameter is incorrect. ```js Property.multilink( [ styleProperty, activeProperty, colorProperty ], ( style, active, lineWidth ) => { // some algorithm that uses style and active } ); ``` - [x] ES5 getters/setters defined in sims should be used judiciously when a Property exists, only when the benefit of conciseness outweighs the potential loss of readability. If ES5 getters/setters exist, try to not mix usage of them with Property access. - [x] The model and view code should be written such that it makes no assumptions about the animation frame rate this it will encounter. The default max dt (delta time) value is defined in `Screen.js`, and smaller values should be used if the default is too large. There is no minimum value for dt, which implies that there is no maximum supported frame rate. The sim should be able to handle this. For an example of a problem that resulted from assuming that a max rate of 60 FPS would be the norm, please see [this GitHub issue](https://github.com/phetsims/states-of-matter/issues/354). ### Documentation This section deals with PhET documentation conventions. You do not need to exhaustively check every item in this section, nor do you necessarily need to check these items one at a time. The goal is to determine whether the code generally meets PhET standards. - [x] All classes, methods and properties are documented. - [x] Documentation at the top of .js files should provide an overview of purpose, responsibilies, and (where useful) examples of API use. If the file contains a subclass definition, it should indicate what functionality it adds to the superclass. - [x] The HTML5/CSS3/JavaScript source code must be reasonably well documented. This is difficult to specify precisely, but the idea is that someone who is moderately experienced with HTML5/CSS3/JavaScript can quickly understand the general function of the source code as well as the overall flow of the code by reading through the comments. For an example of the type of documentation that is required, please see the example-sim repository. - [x] Differentiate between `Property` and "property" in comments. They are different things. `Property` is a type in AXON; property is any value associated with a JavaScript object. Often "field" can be used in exchange for "property" which can help with clarity. Search for "property" to identify violations. - [x] #49 - [x] Line comments should generally be preceded by a blank line. For example: ```js // Randomly choose an existing crystal to possibly bond to const crystal = this.crystals.get( _.random( this.crystals.length - 1 ) ); // Find a good configuration to have the particles move toward const targetConfiguration = this.getTargetConfiguration( crystal ); ``` - [x] When documenting conditionals (if/else statements), follow these guidlines: 1. Comments above the first `if` in a conditional should be about the entire conditional, not just the if block. 2. Comments should not break up sections of the conditional. 3. If a comment is needed to describe a single block of the conditional, then add that comment just inside the block (no space between the `if`/`else if`/`else` and the comment), with a space below it as to not be confused with a comment about logic below. ```js // Comment about the reason to split on peppers were pickled. if( peterPiperPickedAJarOfPickledPeppers ){ // if we want to explain what this `if` statement is about peterAlsoHasBrine(); } else { // documentation about why we have no peppers. This is about the next line of code, and not the "else as a whole block." peterHasNoPeppers(); } ``` - [x] Line comments should have whitespace between the `//` and the first letter of the line comment. See the preceding example. - [x] Do the `@author` annotations seem correct? - [x] Constructor and function documentation. Parameter types and names should be clearly specified for each constructor and function using `@param` annotations. The description for each parameter should follow a hyphen. Primitive types should use lower case. For example: ```js /** * The PhetDeveloper is responsible for creating code for simulations and documenting their code thoroughly. */ class PhetDeveloper { /** * @param {string} name - full name * @param {number} age - age, in years * @param {boolean} isEmployee - whether this developer is an employee of CU * @param {function} callback - called immediate after coffee is consumed * @param {Property.} hoursProperty - cumulative hours worked * @param {string[]} friendNames - names of friends * @param {Object} [options] */ constructor( name, age, isEmployee, callback, hoursProperty, friendNames, options ) { ... } ... } ``` - [x] For most functions, the same form as above should be used, with a `@returns` annotation which identifies the return type and the meaning of the returned value. Functions should also document any side effects. For extremely simple functions that are just a few lines of simple code, an abbreviated line-comment can be used, for example: `// Computes {Number} distance based on {Foo} foo.` - [x] Abstract methods should be annotated with `@abstract` and should typically throw an Error. For example: ```js /** * Updates this node. * @abstract * @protected */ update() { throw new Error( 'update must be implemented by subclass' ); } ``` #### Type Expressions This section deals with PhET conventions for type expressions. You do not need to exhaustively check every item in this section, nor do you necessarily need to check these items one at a time. The goal is to determine whether the code generally meets PhET standards. - [x] Type expressions should conform approximately to [Google Closure Compiler](https://github.com/google/closure-compiler/wiki/Annotating-JavaScript-for-the-Closure-Compiler) syntax. PhET stretches the syntax in many cases (beyond the scope of this document to describe). - [x] Prefer the most basic/restrictive type expression when defining APIs. For example, if a client only needs to know that a parameter is `{Node}`, don’t describe the parameter as `{Rectangle}`. - [x] All method parameters should have type expressions. For example `@param {number} width`. - [x] In sim-specific code, options and fields should have type expressions when their type is not obvious from the context. “Obvious” typically means that the value type is clearly shown in the righthand-side of the definition. E.g. `const width = 42` clear shows that `width` is `{number}`. E.g. `const checkbox = new Checkbox(…)` clearly shows that `checkbox` is `{Checkbox}`. If the type is obvious from the context, the developer may still provide a type expression at his/her discretion. Examples: ```js // @public {GameState} the current state of the game this.gameState = this.computeGameState(); // @public (read-only) the width of the container this.containerWidth = 150; // @private the checkbox used to show particles this.particlesVisibleCheckbox = new Checkbox(...); ``` - [x] In common code repositories all options and fields should have type expressions, regardless of their visibility, and regardless whether their type is obvious from the context. If the same examples from above appeared in common code: ```js // @public {GameState} the current state of the game this.gameState = this.computeGameState(); // @public (read-only) {number} the width of the container this.containerWidth = 150; // @private {Checkbox} the checkbox used to show particles this.particlesVisibleCheckbox = new Checkbox(...); ``` - [x] Type expressions for Enumeration values should be annotated as instances of that Enumeration, see examples in https://github.com/phetsims/phet-core/blob/master/js/Enumeration.js for more. ```js /** * @param {LeftOrRight} - whichHand */ function getHand( whichHand ){ if( whichHand === LeftOrRight.LEFT ){ return new LeftHand(); } else if( whichHand === LeftOrRight.RIGHT ){ return new RightHand(); } } ``` - [x] Type expressions for functions have a variety of possibilities, increasing in complexity depending on the case. In general note that `{function}` is not enough information. Here are some better options: 1. The most basic option it to use Google Closure Type syntax, for more info see https://github.com/google/closure-compiler/wiki/Types-in-the-Closure-Type-System. This specifies the param/return types, but nothing more. Here are some examples: * `@param {function()} noParamsAndNoReturnValue` * `@param {function(number)} giveMeNumberAndReturnNothing` * `@param {function(number, number):Vector2} getVector2` * `@param {function(new:Node)} createNode - a function that takes the Node constructor` 2. When needing to be a bit more specific, add a name to parameters of the function. Sometimes this is all that is needed for clarity on what the param does: * `@param {function(model:MyModel, length:number, name:string): Node} getLengthNode` * `@param {function(aSelfExplanatoryNameForAString:string): Node} getStringNode` 3. If (2) isn't enough, use English to explain the parameters and return values. This is easy because they are named, and can be easily mentioned: * `@param {function(model:MyModel, length:number, name:string): Node} getLengthNode - returns the length Node that you have always wanted, name is the name of the source of your aspirations, length is a special number according to the following 24 criteria. . .` 4. If needing more complexity, or using jsdoc rendering tools (like PhET-iO documentation does), you must use a JSDoc compatible format, not (2) or (3), and you may need to use the more complicated solution. See JSDoc docs for more info. Here is an example of a named callback: ```js /** * @name mySpecialCallback * Converts a string to a number * @param {string} * @returns {number} */ /** * @param {mySpecialCallback} callback */ x = function( callback) { callback( 'still chocolate' ) }; ``` - [x] Type expressions for anonymous Objects have a variety of possibilities, increasing in complexity depending on the case. 1. When the documentation is close by, then {Object} is still acceptable. This mainly applies to options and similar patterns: * `@param {Object} [options] // this is great because of the extend call 5 lines down` 2. When using an `Object` with specific properties, name them and their types like so: * `@param {name:string, address:{street:string}, returnNode:function(number):Node, [shoeSize:number]} personalData // note that shoeSize is optional here` 3. When you need a bit more explanation, keep the same type expression as (2), but feel free to outline specifics in English after the param name. ``` @ param {name:string, address:{street:string}, returnNode:function(number):Node, [shoeSize:number]} personalData - use english after to explain pieces of this (if needed, outline properties on their own lines) name is something address is something else returnNode does this thing ``` 4. Not all objects have named keys like (2) and (3). Here is how to document dictionary-like `Object`s, where each key is some type, and the value is another type. For key value pairs use this: * `{Object.}` Where keys are strings, and values are numbers. * `{Object.}` - naming each of these can help identify them too. Feel free to explain in English after the type expression if needed. 5. If things are too complicated for the above cases, use a `*Def.js` file (especially is used in more than one file), or a `@typedef` declaration right above the jsdoc that uses the typedef. - [x] Look for cases where the use of type expressions involving Property subclasses are incorrect. Because of the structure of the `Property` class hierarchy, specifying type-specific Properties (`{BooleanProperty}`, `{NumberProperty}`,...) may be incorrect, because it precludes values of type `{DerivedProperty}` and `{DynamicProperty}`. Similarly, use of `{DerivedProperty}` and `{DynamicProperty}` precludes values of (e.g.) `{BooleanProperty}`. Especially in common code, using `{Property.}` is typically correct, unless some specific feature of the `Property` subclass is required. For example, `{Property.}` instead of `{BooleanProperty}`. #### Visibility Annotations This section deals with PhET conventions for visibility annotations. You do not need to exhaustively check every item in this section, nor do you necessarily need to check these items one at a time. The goal is to determine whether the code generally meets PhET standards. Because JavaScript lacks visibility modifiers (public, protected, private), PhET uses JSdoc visibility annotations to document the intent of the programmer, and define the public API. Visibility annotations are required for anything that JavaScript makes public. Information about these annotations can be found here. (Note that other documentation systems like the Google Closure Compiler use slightly different syntax in some cases. Where there are differences, JSDoc is authoritative. For example, use `Array.

phetsims / density-buoyancy-common

Code Review #5

PhET Code-Review Checklist (a.k.a "CRC")

Specific Instructions

GitHub Issues