Code Review

[samreid]

Today @jessegreenberg met with me and @matthew-blackman to kick off the code review.

Checklist:

To begin a code review:

• Copy this checklist to a GitHub issue titled "Code Review" and labeled dev:code-review.
• Delete the Table of Contents section, since the links will be incorrect. DONE
• Delete items and sections that are not relevant.
• Replace {{GITHUB_ISSUE_LINK}} with links to GitHub issues.
• Fill in (or delete) the Specific Instructions section.

---

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

• The responsible dev is responsible for removing the irrelevant parts
• A checked-off item doesn't mean "no problem here", it means "it was reviewed"
• Problems can be noted in side issues that reference this issue, or through // REVIEW comments in the code

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.

• model.md, see {{GITHUB_ISSUE_LINK}}. Familiarize yourself with the model by reading model.md. Does it adequately describe the model, in terms appropriate for teachers? Has it been reviewed by the sim designer?
• implementation-notes.md, see {{GITHUB_ISSUE_LINK}}. Familiarize yourself with the implementation by reading implementation-notes.md. Does it provide an overview that will be useful to future maintainers?
• 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.

• Does the sim build without warnings or errors?
• Does the html file size seem reasonable, compared to other similar sims?
• Does the sim start up? (unbuilt and built versions)
• Does the sim experience any assertion failures? (run with query parameter ea)
• Does the sim pass a scenery fuzz test? (run with query parameters fuzz&ea)
• Does the sim behave correctly when listener order is shuffled? (run with query parameters ea&shuffleListeners and ea&shuffleListeners&fuzz)
• Does the sim output any deprecation warnings? Run with ?deprecationWarnings. Do not use deprecated methods in new code.

Memory Leaks

• Does a heap comparison using Chrome Developer Tools indicate a memory leak? (This process is described here.) 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}}.
• 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. Note that it's also acceptable (and encouraged!) to describe what needs to be disposed in implementation-notes.md.
• Are there leaks due to registering observers or listeners? The following guidelines should be followed unless documentation (in-line or in implementation-notes.md) describes why following them is not necessary.
  • AXON: Property.link or lazyLink is accompanied by unlink.
  • AXON: Multilink.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.
• 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

• 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.
• If the sim uses WebGL, does it have a fallback? Does the fallback perform reasonably well? (run with query parameter webgl=false)

Usability

• Are UI components sufficiently responsive? (especially continuous UI components, such as sliders)
• Are pointer areas optimized, especially for touch? (run with query parameter showPointerAreas)
• 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

• 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.)

• Does the sim layout gracefully handle internationalized strings that are longer than the English strings? (run with query parameters stringTest=double and stringTest=long)

• 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

• 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.

• Use named placeholders (e.g. "{{value}} {{units}}") instead of numbered placeholders (e.g. "{0} {1}").

• 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.:

  "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.:

  // 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.:

  "simplifyTitle": {
     value: "Simplify!"
  },
  "simplifyCheckbox": {
     value: "simplify"
  }

  (4) String keys for screen names should have the general form "screen.{{screenName}}". E.g.:

    "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.
  (6) It is acceptable to prefix families of strings with a prefix, like so:

  "material.water": {
    "value": "Water"
  },
  "material.wood": {
    "value": "Wood"
  },
  "shape.block": {
    "value": "Block"
  },
  "shape.cone": {
    "value": "Cone"
  },

Nested substructure is not yet fully supported.

• 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 Translations will lose some strings the next time this is published off of master gravity-force-lab#166 should be created).

Repository Structure

• 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".

• 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.

• 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.

• Is the js/ directory properly structured?
  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
  

• 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
  repository, 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.

• Is there a file in assets/ for every resource file in sound/ and images/? Note that there is not necessarily a
  1:1 correspondence between asset and resource files; for example, several related images may be in the same .ai file.
  Check license.json for possible documentation of why some resources might not have a corresponding asset file.

• For simulations, was the README.md generated by grunt published-README or grunt unpublished-README? Common
  code repos can have custom README files.

• Does package.json refer to any dependencies that are not used by the sim?

• Is the LICENSE file correct? (Generally GPL v3 for sims and MIT for common code,
  see this thread for additional information).

• Does .gitignore match the one in simula-rasa?

• In GitHub, verify that all non-release branches have an associated issue that describes their purpose.

• Are there any GitHub branches that are no longer needed and should be deleted?

• 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 arithmetic repository, or FBQueryParameters.js for Function Builder (where
  the FB prefix is used).

• Query parameters that are public-facing should be identified using public: true in the schema.

• 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
  PhET-iO instrumentation for ColorProfile scenery-phet#515. Please see
  GasPropertiesColors.js
  for a good example.

Coding Conventions

• Are coding conventions outlined in PhET's Coding Conventions Document followed and adhered to? This document
  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.

TypeScript Conventions

• Are TypeScript conventions outlined in the TypeScript Conventions Document followed and adhered to?

Math Libraries

• DOT/Utils.toFixed or DOT/Utils.toFixedNumber should be used instead of toFixed. JavaScript's toFixed is notoriously buggy. Behavior differs depending on browser, because the spec doesn't specify whether to round or floor.

IE11

• IE is no longer supported. With that in mind remove IE-specific workarounds
• Use string.includes and string.startsWith where possible.

Organization, Readability, and Maintainability

• Does the organization and structure of the code make sense? Do the model and view contain types that you would expect (or guess!) by looking at the sim? Do the names of things correspond to the names that you see in the user interface?
• Are appropriate design patterns used? See phet-software-design-patterns.md. If new or inappropriate patterns are identified, create an issue.
• Is inheritance used where appropriate? Does the type hierarchy make sense?
• Is composition favored over inheritance where appropriate? See https://en.wikipedia.org/wiki/Composition_over_inheritance.
• Is there any unnecessary coupling? (e.g., by passing large objects to constructors, or exposing unnecessary properties/functions). In TypeScript, you can decouple by narrowing the API like so:

  public constructor( tickMarksVisibleProperty: Property<boolean>,
                      model: Pick<IntroModel, 'changeWaterLevel'>, // <-- Note the call site can pass the whole model, but we declare we will only use this part of it
                      waterCup: WaterCup, modelViewTransform: ModelViewTransform2,
                      providedOptions?: WaterCup3DNodeOptions ) {

• Is there too much unnecessary decoupling? (e.g. by passing all of the properties of an object independently instead of passing the object itself)?
• Are the source files reasonable in size? Scrutinize large files with too many responsibilities - can responsibilities be broken into smaller delegates?
• Are any significant chunks of code duplicated? In addition to manual identification, tools include: WebStorm Code > Analyze Code > Locate Duplicates and https://github.com/danielstjules/jsinspect.
• Is there anything that should be generalized and migrated to common code?
• Are there any TODO or FIXME or REVIEW comments in the code? They should be addressed or promoted to GitHub issues.
• Are there any magic numbers that should be factored out as constants and documented?
• Are there any constants that are duplicated in multiple files that should be factored out into a {{REPO}}Constants.js file?
• Does the implementation rely on any specific constant values that are likely to change in the future? Identify constants that might be changed in the future. (Use your judgement about which constants are likely candidates.) Does changing the values of these constants break the sim? For example, see allow minimum rows to go to "1" and address dependency on current minimum of "5" plinko-probability#84.
• Is PhetColorScheme used where appropriate? Verify that the sim is not inventing/creating its own colors for things that have been standardized in PhetColorScheme. Identify any colors that might be worth adding to PhetColorScheme.
• Are all dependent Properties modeled as DerivedProperty instead of Property?
• All dynamics should be called from Sim.step(dt), do not use window.setTimeout or window.setInterval. This will help support Legends of Learning and PhET-iO.

Accessibility

This section may be omitted if the sim has not been instrumented with accessibility features. Accessibility includes
various features, not all are always include. Ignore sections that do not apply.

General

• Are accessibility features integrated well into the code. They should be added in a maintainable way, even if that requires upfront refactoring.

Alternative Input

• Does the sim pass an accessibility fuzz test? (run with query parameters fuzzBoard&ea)
• Does this sim use specific keyboard shortcuts that overlap with global shortcuts? This includes the use of modifier keys like in Unintended zoom/keyboard behavior ratio-and-proportion#287. NOTE: There is currently no list of global shortcuts, and therefore no way to complete this checklist item. See Create a list of global keyboard shortcuts. phet-info#188.

Interactive Description

• Run the entire built sim HTML file through an HTML validator, does the HTML pass?
• If applicable, are good design patterns used for interactive description, see interactive-description-technical-guide.md
• Does resetting the simulation also reset the entire PDOM?
• Is Node.pdomOrder used appropriately to maintain visual and PDOM layout balance?
• Make sure accessibility strings aren't being adjusted with ascii specific javascript methods like toUpperCase(). Remember that one day these strings will be translatable
• Make sure for accessibility strings that all end of sentence periods do not have a leading space before it. Some screen readers will read these as "dot." This can occur often when a clause is conditionally added.

PhET-iO

This section may be omitted if the sim has not been instrumented for PhET-iO, but is likely good to glance at no matter.

• Does instrumentation follow the conventions described in PhET-iO Instrumentation Guide?
  This could be an extensive bullet. At the very least, be sure to know what amount of instrumentation this sim
  supports. Describing this further goes beyond the scope of this document.
• PhET-iO instantiates different objects and wires up listeners that are not present in the PhET-branded simulation.
  It needs to be tested separately for memory leaks. To help isolate the nature of the memory leak, this test should
  be run separately from the PhET brand memory leak test. Test with a colorized Data Stream, and Studio (easily
  accessed from phetmarks). Compare to testing results done by the responsible developer and previous releases.
• Make sure unused PhetioObject instances are disposed, which unregisters their tandems.
• Make sure JOIST dt values are used instead of Date.now() or other Date functions. Perhaps try
  phet.joist.elapsedTime. Though this has already been mentioned, it is necessary for reproducible playback via input
  events and deserves a comment in this PhET-iO section.
• Are random numbers using DOT/dotRandom as an imported module (not a global), and all doing so after modules are declared (non-statically)? For
  example, the following methods (and perhaps others) should not be used: Math.random, _.shuffle, _.sample, _.random.
  This also deserves re-iteration due to its effect on record/playback for PhET-iO.
• Like JSON, keys for undefined values are omitted when serializing objects across frames. Consider this when
  determining whether toStateObject should use null or undefined values.
• PhET prefers to use the term "position" to refer to the physical (x,y) position of objects. This applies to both
  brands, but is more important for the PhET-iO API. See location vs position phet-info#126
• Are your IOType state methods violating the API of the core type by accessing private fields?
• When defining a boolean Property to indicate whether something is enabled, use AXON/EnabledProperty. This
  should be done in both the model and the view. If you're using a DerivedProperty, skip this item.
• Do not use translated strings in phetioDocumentaton - it changes the PhET-iO API!

[samreid]

As I take an initial look in the code, I'm seeing that things are well-documented and readable, and looking in very good shape. Nice work! I wanted to start a discussion checklist of things to ask about--some of them more stylistic and about consistency across repos, and I wouldn't feel comfortable committing changes without discussing:

• Can we export default inline? Like https://github.com/phetsims/balancing-chemical-equations/blob/f78783eeb2f32bf1572f7aed1dcab3b376912252/js/common/model/AtomCount.ts#L18. @jessegreenberg agreed this is a good idea and @samreid will implement it.
• I'm seeing a lot of Tandem but phet-io is not listed as a supported brand. How would you characterize the phet-io coverage? Is phet-io publication planned in the near future? @jessegreenberg says PhET-iO was added early on for some prototyping, but it is not thorough and not planned for production in the foreseeable future.
• I'm seeing places where constructor properties could be used like so:

Subject: [PATCH] constructor properties
---
Index: js/quadrilateral/view/SideTicksNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/js/quadrilateral/view/SideTicksNode.ts b/js/quadrilateral/view/SideTicksNode.ts
--- a/js/quadrilateral/view/SideTicksNode.ts	(revision 5fbeaa88abbea17b05824e82b473027f60b711db)
+++ b/js/quadrilateral/view/SideTicksNode.ts	(date 1677738730918)
@@ -25,10 +25,8 @@
 const SCRATCH_LINE = new Line( new Vector2( 0, 0 ), new Vector2( 0, 0 ) );
 
 class SideTicksNode extends Path {
-  private readonly side: QuadrilateralSide;
-  private readonly modelViewTransform: ModelViewTransform2;
 
-  public constructor( side: QuadrilateralSide, modelViewTransform: ModelViewTransform2 ) {
+  public constructor( private readonly side: QuadrilateralSide, private readonly modelViewTransform: ModelViewTransform2 ) {
     super( null, {
       stroke: QuadrilateralColors.quadrilateralShapeStrokeColorProperty
     } );

In discussion, @jessegreenberg and I agreed not to use that pattern in this sim.

• What would the tradeoffs be of rewriting with bamboo? In discussion with @jessegreenberg, we thought bamboo may render the grid. But after seeing QuadrilateralGridNode, it is very simple and only 100 lines of code, so it may not be advantageous to bring in a new dependency for that.
• Maybe dispose the tangibleControlsTitle in case it one day becomes i18nized? It's in the prototype realm though, so may not be on the road to i18n.
• Does this sim mostly have static things? I don't see a lot of dispose implementation (outside of sound)
• No memory growth over 1 minute of fuzzing, great job!
• I've seen some devs start to prefer string literal unions over using EnumerationValue. This sim uses 5 EnumerationValue vs 1 string literal union (ResponseReason). Is that where we want to be for long-term maintainability? @jessegreenberg and I agreed this sim will continue to mostly use EnumerationValue
• Since leftConstrainedProperty etc are initialized at the declaration site, we could do that for numberOfConstrainingEdgesProperty as well. (But if those ever get phet-io tandems, they probably would all have to move into the constructor). CONSENSUS: Yes, we prefer initialization at declaration site.

Subject: [PATCH] constructor properties
---
Index: js/quadrilateral/model/QuadrilateralVertex.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/js/quadrilateral/model/QuadrilateralVertex.ts b/js/quadrilateral/model/QuadrilateralVertex.ts
--- a/js/quadrilateral/model/QuadrilateralVertex.ts	(revision 5fbeaa88abbea17b05824e82b473027f60b711db)
+++ b/js/quadrilateral/model/QuadrilateralVertex.ts	(date 1677739581193)
@@ -56,7 +56,18 @@
   public readonly rightConstrainedProperty = new BooleanProperty( false );
   public readonly topConstrainedProperty = new BooleanProperty( false );
   public readonly bottomConstrainedProperty = new BooleanProperty( false );
-  public readonly numberOfConstrainingEdgesProperty: TReadOnlyProperty<number>;
+  public readonly numberOfConstrainingEdgesProperty = new DerivedProperty( [
+    this.topConstrainedProperty,
+    this.rightConstrainedProperty,
+    this.bottomConstrainedProperty,
+    this.leftConstrainedProperty
+  ], ( topConstrained, rightConstrained, bottomConstrained, leftConstrained ) => {
+    const topVal = topConstrained ? 1 : 0;
+    const rightVal = rightConstrained ? 1 : 0;
+    const bottomVal = bottomConstrained ? 1 : 0;
+    const leftVal = leftConstrained ? 1 : 0;
+    return topVal + rightVal + bottomVal + leftVal;
+  } );
 
   // A reference to vertices connected to this vertex for so we can calculate the angle at this vertex.
   // The orientation of vertex1 and vertex2 for angle calculations are as shown in the following diagram:
@@ -110,18 +121,6 @@
       return new Bounds2( position.x - HALF_WIDTH, position.y - HALF_HEIGHT, position.x + HALF_WIDTH, position.y + HALF_HEIGHT );
     } );
 
-    this.numberOfConstrainingEdgesProperty = new DerivedProperty( [
-      this.topConstrainedProperty,
-      this.rightConstrainedProperty,
-      this.bottomConstrainedProperty,
-      this.leftConstrainedProperty
-    ], ( topConstrained, rightConstrained, bottomConstrained, leftConstrained ) => {
-      const topVal = topConstrained ? 1 : 0;
-      const rightVal = rightConstrained ? 1 : 0;
-      const bottomVal = bottomConstrained ? 1 : 0;
-      const leftVal = leftConstrained ? 1 : 0;
-      return topVal + rightVal + bottomVal + leftVal;
-    } );
 
     this.tandem = tandem;
   }

• Clarify the number of points in the array? I'm not sure if the change is accurate:

Subject: [PATCH] constructor properties
---
Index: js/quadrilateral/model/QuadrilateralVertex.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/js/quadrilateral/model/QuadrilateralVertex.ts b/js/quadrilateral/model/QuadrilateralVertex.ts
--- a/js/quadrilateral/model/QuadrilateralVertex.ts	(revision 5fbeaa88abbea17b05824e82b473027f60b711db)
+++ b/js/quadrilateral/model/QuadrilateralVertex.ts	(date 1677739825789)
@@ -72,7 +72,7 @@
   // controlled by a prototype tangible. See smoothPosition().
   private readonly smoothingLengthProperty: TReadOnlyProperty<number>;
 
-  // The collection of SMOOTHING_LENGTH number of positions for prototype tangible control. See smoothPosition().
+  // The collection of n <= SMOOTHING_LENGTH number of positions for prototype tangible control. See smoothPosition().
   private readonly positions: Vector2[] = [];
 
   // in model coordinates, the width of the QuadrilateralVertex

• Mark the array elements as unchangeable?

Subject: [PATCH] constructor properties
---
Index: js/quadrilateral/model/ShapeSnapshot.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/js/quadrilateral/model/ShapeSnapshot.ts b/js/quadrilateral/model/ShapeSnapshot.ts
--- a/js/quadrilateral/model/ShapeSnapshot.ts	(revision 5fbeaa88abbea17b05824e82b473027f60b711db)
+++ b/js/quadrilateral/model/ShapeSnapshot.ts	(date 1677739911289)
@@ -36,7 +36,7 @@
   public readonly sideBCLength: number;
   public readonly sideDALength: number;
   public readonly sideCDLength: number;
-  private readonly sideLengths: number[];
+  private readonly sideLengths: readonly number[];
 
   public constructor( shapeModel: QuadrilateralShapeModel ) {
     this.isParallelogram = shapeModel.isParallelogramProperty.value;

• ~Why are the Utterances like lowPriorityUtterance created in advance and re-used instead of on-demand and single-use? ~ @jessegreenberg says: A single instance of an utterance is reused to leverage the utterance queue feature of collapsing the utterances so only the most recent one (added to the back last) from that priority level is spoken.

[samreid]

• Should we center the label on creation?

Subject: [PATCH] Use ternary operator, see https://github.com/phetsims/quadrilateral/issues/398
---
Index: js/quadrilateral/view/QuadrilateralIconFactory.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/js/quadrilateral/view/QuadrilateralIconFactory.ts b/js/quadrilateral/view/QuadrilateralIconFactory.ts
--- a/js/quadrilateral/view/QuadrilateralIconFactory.ts	(revision 4266288d3e5c19b3d84ef0bdad529510169aa581)
+++ b/js/quadrilateral/view/QuadrilateralIconFactory.ts	(date 1677770615285)
@@ -24,13 +24,13 @@
    * Creates an icon for the "Corner Labels" checkbox that toggles visibility of labels on each QuadrilateralVertex.
    */
   createCornerLabelsIcon(): Node {
-    const label = new Text( 'A', QuadrilateralConstants.SCREEN_TEXT_OPTIONS );
+
     const circle = new Circle( QuadrilateralIconFactory.ICON_HEIGHT / 2, {
       stroke: QuadrilateralColors.visibilityIconsColorProperty,
       lineWidth: QuadrilateralIconFactory.ICON_LINE_WIDTH
     } );
 
-    label.center = circle.center;
+    const label = new Text( 'A', { center: circle.center, ...QuadrilateralConstants.SCREEN_TEXT_OPTIONS } );
     circle.addChild( label );
 
     return circle;

[samreid]

Current patch for QuadrilateralShapeDetector:

Subject: [PATCH] Add REVIEW comments, see https://github.com/phetsims/quadrilateral/issues/398
---
Index: js/quadrilateral/model/QuadrilateralShapeDetector.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/js/quadrilateral/model/QuadrilateralShapeDetector.ts b/js/quadrilateral/model/QuadrilateralShapeDetector.ts
--- a/js/quadrilateral/model/QuadrilateralShapeDetector.ts	(revision a7db24118c6c8642e6e2018e7f282b5f7300cbec)
+++ b/js/quadrilateral/model/QuadrilateralShapeDetector.ts	(date 1677801894817)
@@ -19,79 +19,93 @@
  * @author Jesse Greenberg (PhET Interactive Simulations)
  */
 
-/* eslint-disable no-bitwise*/
-
 import quadrilateral from '../../quadrilateral.js';
 import QuadrilateralShapeModel from './QuadrilateralShapeModel.js';
 import NamedQuadrilateral from './NamedQuadrilateral.js';
 
 // Set up the bits for each shape property.
-const CONCAVE = Math.pow( 2, 0 );
-const ONE_PARALLEL_PAIR = Math.pow( 2, 1 );
-const TWO_PARALLEL_PAIR = Math.pow( 2, 2 );
-const TWO_EQUAL_ADJACENT_ANGLE_PAIR = Math.pow( 2, 4 ); // REVIEW: Are we skipping 3?
-const ONE_EQUAL_OPPOSITE_ANGLE_PAIR = Math.pow( 2, 5 );
-const TWO_EQUAL_OPPOSITE_ANGLE_PAIR = Math.pow( 2, 6 );
-const ALL_EQUAL_ANGLE = Math.pow( 2, 7 );// REVIEW: Are we skipping 8?
-const TWO_EQUAL_ADJACENT_SIDE_PAIR = Math.pow( 2, 9 );
-const ONE_EQUAL_OPPOSITE_SIDE_PAIR = Math.pow( 2, 10 );
-const TWO_EQUAL_OPPOSITE_SIDE_PAIR = Math.pow( 2, 11 );
-const ALL_EQUAL_SIDE = Math.pow( 2, 12 );
-const ONE_ANGLE_PIE = Math.pow( 2, 13 );
+const CONCAVE = 'CONCAVE';
+const ONE_PARALLEL_PAIR = 'ONE_PARALLEL_PAIR';
+const TWO_PARALLEL_PAIR = 'TWO_PARALLEL_PAIR';
+const TWO_EQUAL_ADJACENT_ANGLE_PAIR = 'TWO_EQUAL_ADJACENT_ANGLE_PAIR';
+const ONE_EQUAL_OPPOSITE_ANGLE_PAIR = 'ONE_EQUAL_OPPOSITE_ANGLE_PAIR';
+const TWO_EQUAL_OPPOSITE_ANGLE_PAIR = 'TWO_EQUAL_OPPOSITE_ANGLE_PAIR';
+const ALL_EQUAL_ANGLE = 'ALL_EQUAL_ANGLE';
+const TWO_EQUAL_ADJACENT_SIDE_PAIR = 'TWO_EQUAL_ADJACENT_SIDE_PAIR';
+const ONE_EQUAL_OPPOSITE_SIDE_PAIR = 'ONE_EQUAL_OPPOSITE_SIDE_PAIR';
+const TWO_EQUAL_OPPOSITE_SIDE_PAIR = 'TWO_EQUAL_OPPOSITE_SIDE_PAIR';
+const ALL_EQUAL_SIDE = 'ALL_EQUAL_SIDE';
+const ONE_ANGLE_PIE = 'ONE_ANGLE_PIE';
 
 // Set up shape masks for each shape. The quadrilateral must at least these attributes to be considered a match.
-const CONCAVE_MASK = CONCAVE;
+const CONCAVE_REQUIREMENTS = [ CONCAVE ];
 
-const TRIANGLE_MASK = ONE_ANGLE_PIE;
+const TRIANGLE = [ ONE_ANGLE_PIE ];
 
-const DART_MASK = CONCAVE |
-                  ONE_EQUAL_OPPOSITE_ANGLE_PAIR |
-                  TWO_EQUAL_ADJACENT_SIDE_PAIR;
+const DART = [
+  CONCAVE,
+  ONE_EQUAL_OPPOSITE_ANGLE_PAIR,
+  TWO_EQUAL_ADJACENT_SIDE_PAIR
+];
 
-const KITE_MASK = ONE_EQUAL_OPPOSITE_ANGLE_PAIR |
-                  TWO_EQUAL_ADJACENT_SIDE_PAIR;
+const KITE = [
+  ONE_EQUAL_OPPOSITE_ANGLE_PAIR,
+  TWO_EQUAL_ADJACENT_SIDE_PAIR
+];
 
-const TRAPEZOID_MASK = ONE_PARALLEL_PAIR;
+const TRAPEZOID = [
+  ONE_PARALLEL_PAIR
+];
 
-const ISOSCELES_TRAPEZOID_MASK = ONE_PARALLEL_PAIR |
-                                 TWO_EQUAL_ADJACENT_ANGLE_PAIR |
-                                 ONE_EQUAL_OPPOSITE_SIDE_PAIR;
+const ISOSCELES_TRAPEZOID = [
+  ONE_PARALLEL_PAIR,
+  TWO_EQUAL_ADJACENT_ANGLE_PAIR,
+  ONE_EQUAL_OPPOSITE_SIDE_PAIR
+];
 
-const PARALLELOGRAM_MASK = ONE_PARALLEL_PAIR |
-                           TWO_PARALLEL_PAIR |
-                           ONE_EQUAL_OPPOSITE_ANGLE_PAIR |
-                           TWO_EQUAL_OPPOSITE_ANGLE_PAIR |
-                           ONE_EQUAL_OPPOSITE_SIDE_PAIR |
-                           TWO_EQUAL_OPPOSITE_SIDE_PAIR;
+const PARALLELOGRAM = [
+  ONE_PARALLEL_PAIR,
+  TWO_PARALLEL_PAIR,
+  ONE_EQUAL_OPPOSITE_ANGLE_PAIR,
+  TWO_EQUAL_OPPOSITE_ANGLE_PAIR,
+  ONE_EQUAL_OPPOSITE_SIDE_PAIR,
+  TWO_EQUAL_OPPOSITE_SIDE_PAIR
+];
 
-const RECTANGLE_MASK = ONE_PARALLEL_PAIR |
-                       TWO_PARALLEL_PAIR |
-                       TWO_EQUAL_ADJACENT_ANGLE_PAIR |
-                       ONE_EQUAL_OPPOSITE_ANGLE_PAIR |
-                       TWO_EQUAL_OPPOSITE_ANGLE_PAIR |
-                       ALL_EQUAL_ANGLE |
-                       ONE_EQUAL_OPPOSITE_SIDE_PAIR |
-                       TWO_EQUAL_OPPOSITE_SIDE_PAIR;
+const RECTANGLE = [
+  ONE_PARALLEL_PAIR,
+  TWO_PARALLEL_PAIR,
+  TWO_EQUAL_ADJACENT_ANGLE_PAIR,
+  ONE_EQUAL_OPPOSITE_ANGLE_PAIR,
+  TWO_EQUAL_OPPOSITE_ANGLE_PAIR,
+  ALL_EQUAL_ANGLE,
+  ONE_EQUAL_OPPOSITE_SIDE_PAIR,
+  TWO_EQUAL_OPPOSITE_SIDE_PAIR
+];
 
-const RHOMBUS_MASK = ONE_PARALLEL_PAIR |
-                     TWO_PARALLEL_PAIR |
-                     ONE_EQUAL_OPPOSITE_ANGLE_PAIR |
-                     TWO_EQUAL_OPPOSITE_ANGLE_PAIR |
-                     TWO_EQUAL_ADJACENT_SIDE_PAIR |
-                     ONE_EQUAL_OPPOSITE_SIDE_PAIR |
-                     TWO_EQUAL_OPPOSITE_SIDE_PAIR |
-                     ALL_EQUAL_SIDE;
+const RHOMBUS = [
+  ONE_PARALLEL_PAIR,
+  TWO_PARALLEL_PAIR,
+  ONE_EQUAL_OPPOSITE_ANGLE_PAIR,
+  TWO_EQUAL_OPPOSITE_ANGLE_PAIR,
+  TWO_EQUAL_ADJACENT_SIDE_PAIR,
+  ONE_EQUAL_OPPOSITE_SIDE_PAIR,
+  TWO_EQUAL_OPPOSITE_SIDE_PAIR,
+  ALL_EQUAL_SIDE
+];
 
-const SQUARE_MASK = ONE_PARALLEL_PAIR |
-                    TWO_PARALLEL_PAIR |
-                    TWO_EQUAL_ADJACENT_ANGLE_PAIR |
-                    ONE_EQUAL_OPPOSITE_ANGLE_PAIR |
-                    TWO_EQUAL_OPPOSITE_ANGLE_PAIR |
-                    ALL_EQUAL_ANGLE |
-                    TWO_EQUAL_ADJACENT_SIDE_PAIR |
-                    ONE_EQUAL_OPPOSITE_SIDE_PAIR |
-                    TWO_EQUAL_OPPOSITE_SIDE_PAIR |
-                    ALL_EQUAL_SIDE;
+const SQUARE = [
+  ONE_PARALLEL_PAIR,
+  TWO_PARALLEL_PAIR,
+  TWO_EQUAL_ADJACENT_ANGLE_PAIR,
+  ONE_EQUAL_OPPOSITE_ANGLE_PAIR,
+  TWO_EQUAL_OPPOSITE_ANGLE_PAIR,
+  ALL_EQUAL_ANGLE,
+  TWO_EQUAL_ADJACENT_SIDE_PAIR,
+  ONE_EQUAL_OPPOSITE_SIDE_PAIR,
+  TWO_EQUAL_OPPOSITE_SIDE_PAIR,
+  ALL_EQUAL_SIDE
+];
 
 export default class QuadrilateralShapeDetector {
   private readonly quadrilateralShapeModel: QuadrilateralShapeModel;
@@ -108,7 +122,7 @@
    * QuadrilateralShapeModel.updateOrderDependentProperties for more information.
    */
   public getShapeName(): NamedQuadrilateral {
-    let currentConditionMask = 0;
+    const conditions: string[] = [];
 
     // First, assemble a bitwise value representing the attributes of the current shape. Start by looking for
     // a triangle, which is a unique case. If we have a triangle we can stop looking for more properties
@@ -116,60 +130,60 @@
     // to produce the final properties of the shape.
     const shapeModel = this.quadrilateralShapeModel;
     if ( _.some( shapeModel.vertices, vertex => shapeModel.isFlatAngle( vertex.angleProperty.value! ) ) ) {
-      currentConditionMask = currentConditionMask | TRIANGLE_MASK;
+      conditions.push( ONE_ANGLE_PIE );
     }
     else {
       if ( _.some( shapeModel.vertices, vertex => vertex.angleProperty.value! > Math.PI ) ) {
-        currentConditionMask = currentConditionMask | CONCAVE;
+        conditions.push( CONCAVE );
       }
       if ( shapeModel.parallelSidePairsProperty.value.length > 0 ) {
-        currentConditionMask = currentConditionMask | ONE_PARALLEL_PAIR;
+        conditions.push( ONE_PARALLEL_PAIR );
       }
       if ( shapeModel.parallelSidePairsProperty.value.length > 1 ) {
-        currentConditionMask = currentConditionMask | TWO_PARALLEL_PAIR;
+        conditions.push( TWO_PARALLEL_PAIR );
       }
       if ( shapeModel.adjacentEqualVertexPairsProperty.value.length > 1 ) {
-        currentConditionMask = currentConditionMask | TWO_EQUAL_ADJACENT_ANGLE_PAIR;
+        conditions.push( TWO_EQUAL_ADJACENT_ANGLE_PAIR );
       }
       if ( shapeModel.oppositeEqualVertexPairsProperty.value.length > 0 ) {
-        currentConditionMask = currentConditionMask | ONE_EQUAL_OPPOSITE_ANGLE_PAIR;
+        conditions.push( ONE_EQUAL_OPPOSITE_ANGLE_PAIR );
       }
       if ( shapeModel.oppositeEqualVertexPairsProperty.value.length > 1 ) {
-        currentConditionMask = currentConditionMask | TWO_EQUAL_OPPOSITE_ANGLE_PAIR;
+        conditions.push( TWO_EQUAL_OPPOSITE_ANGLE_PAIR );
       }
       if ( shapeModel.allAnglesRightProperty.value ) {
-        currentConditionMask = currentConditionMask | ALL_EQUAL_ANGLE;
+        conditions.push( ALL_EQUAL_ANGLE );
       }
       if ( shapeModel.adjacentEqualSidePairsProperty.value.length > 1 ) {
-        currentConditionMask = currentConditionMask | TWO_EQUAL_ADJACENT_SIDE_PAIR;
+        conditions.push( TWO_EQUAL_ADJACENT_SIDE_PAIR );
       }
       if ( shapeModel.oppositeEqualSidePairsProperty.value.length > 0 ) {
-        currentConditionMask = currentConditionMask | ONE_EQUAL_OPPOSITE_SIDE_PAIR;
+        conditions.push( ONE_EQUAL_OPPOSITE_SIDE_PAIR );
       }
       if ( shapeModel.oppositeEqualSidePairsProperty.value.length > 1 ) {
-        currentConditionMask = currentConditionMask | TWO_EQUAL_OPPOSITE_SIDE_PAIR;
+        conditions.push( TWO_EQUAL_OPPOSITE_SIDE_PAIR );
       }
       if ( shapeModel.allLengthsEqualProperty.value ) {
-        currentConditionMask = currentConditionMask | ALL_EQUAL_SIDE;
+        conditions.push( ALL_EQUAL_SIDE );
       }
     }
 
-    // Find matches for the current condition - Order of these checks is very important. conditionMatchesMask
+    // Find matches for the current condition - Order of these checks is very important. conditionsMatchRequirements
     // returns true if the condition matches the minimum requirements for a shape. But even after there is a match,
     // we will continue to search for the most specific attribute matches.
     let quadrilateralName: NamedQuadrilateral;
 
     // First look for a triangle - it is unique in that if we have a triangle there are no more shapes "under"
     // it that share attributes - so we can return this right away.
-    if ( this.conditionMatchesMask( currentConditionMask, TRIANGLE_MASK ) ) {
+    if ( this.conditionsMatchRequirements( conditions, TRIANGLE ) ) {
       quadrilateralName = NamedQuadrilateral.TRIANGLE;
     }
-    else if ( this.conditionMatchesMask( currentConditionMask, CONCAVE_MASK ) ) {
+    else if ( this.conditionsMatchRequirements( conditions, CONCAVE_REQUIREMENTS ) ) {
 
       // if concave, the only attribute that can "build-up" from here is the dart property
       quadrilateralName = NamedQuadrilateral.CONCAVE_QUADRILATERAL;
 
-      if ( this.conditionMatchesMask( currentConditionMask, DART_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, DART ) ) {
         quadrilateralName = NamedQuadrilateral.DART;
       }
     }
@@ -178,25 +192,25 @@
       // most general case, shape properties "build-up" from a convex quadrilateral
       quadrilateralName = NamedQuadrilateral.CONVEX_QUADRILATERAL;
 
-      if ( this.conditionMatchesMask( currentConditionMask, TRAPEZOID_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, TRAPEZOID ) ) {
         quadrilateralName = NamedQuadrilateral.TRAPEZOID;
       }
-      if ( this.conditionMatchesMask( currentConditionMask, ISOSCELES_TRAPEZOID_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, ISOSCELES_TRAPEZOID ) ) {
         quadrilateralName = NamedQuadrilateral.ISOSCELES_TRAPEZOID;
       }
-      if ( this.conditionMatchesMask( currentConditionMask, KITE_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, KITE ) ) {
         quadrilateralName = NamedQuadrilateral.KITE;
       }
-      if ( this.conditionMatchesMask( currentConditionMask, PARALLELOGRAM_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, PARALLELOGRAM ) ) {
         quadrilateralName = NamedQuadrilateral.PARALLELOGRAM;
       }
-      if ( this.conditionMatchesMask( currentConditionMask, RECTANGLE_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, RECTANGLE ) ) {
         quadrilateralName = NamedQuadrilateral.RECTANGLE;
       }
-      if ( this.conditionMatchesMask( currentConditionMask, RHOMBUS_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, RHOMBUS ) ) {
         quadrilateralName = NamedQuadrilateral.RHOMBUS;
       }
-      if ( this.conditionMatchesMask( currentConditionMask, SQUARE_MASK ) ) {
+      if ( this.conditionsMatchRequirements( conditions, SQUARE ) ) {
         quadrilateralName = NamedQuadrilateral.SQUARE;
       }
     }
@@ -206,18 +220,15 @@
 
   /**
    * Returns true when the condition state matches the conditions of the provided mask. Consider two values
-   * 10110 (mask)
-   * 11110 (condition)
    *
-   * The & operation returns 10110 (the original mask) if the condition has at least the bits of the mask. This is
-   * useful because each mask lists out the requirements for a particular shape. If the condition has at least those
+   * Each mask lists out the requirements for a particular shape. If the condition has at least those
    * requirements (or more) it will still be considered a match for that shape.
    *
-   * @param condition - bits representing the current shape conditions
-   * @param mask - bits representing the requirements for a particular shape
+   * @param condition - current shape conditions
+   * @param requirements - requirements for a particular shape
    */
-  private conditionMatchesMask( condition: number, mask: number ): boolean {
-    return ( condition & mask ) === mask;
+  private conditionsMatchRequirements( conditions: string[], requirements: string[] ): boolean {
+    return requirements.every( maskElement => conditions.includes( maskElement ) );
   }
 }
 

[jessegreenberg]

OK, I hit every review comment and the side issues that came out of this one. Thank you so much for the review @samreid and @matthew-blackman. All recommendations were great improvements for the code and I went with almost all of them. The following two are the only exceptions. Feel free to give thoughts asynchronously, or we could briefly meet to discuss these and the larger changes in side issues.

// REVIEW: In fuzzing, I saw this value go greater than Math.PI*2.
// REVIEW: Can the angle be computed with: const a = vector1.angleBetween( vector2 );

Vector2.angleBetween returns a value between 0 and PI, we need a value from 0-2PI in this sim to support concave quadrilaterals. I fuzzed the sim for 5 minutes or so and never saw an angle above Math.PI * 2. I added a line of doc about why there is a custom angle calculation and then decided not to go farther.

// REVIEW: In this case and others like it, we are plucking several attributes from the model, (potentially) renaming them
// and passing them through. This makes it difficult to trace back to the source.
// An alternative is to pass the entire model through, and use TypeScript to narrow what is accessible
// Note the visibilityModel is also part of the model.

I reivewed the components in QuadrilateralScreenView (where the model is distributed to view subcomponents) and decided not to do this. It didn't seem to improve readability too much. I didn't see a good way for Pick to expose fields on model subcomponents. For example, although visibilityModel is part of the model, I don't want the QuadrilateralDiagonalGuidesNode to take the whole model.visibilityModel, I want it to take just the model.visibilityModel.diagonalGuidesVisibleProperty.

The other two issues you may want to re-sign off on:

• Simplify getNextPositionInDimension #402
• Add unit tests #404

[samreid]

The comments above seem good, thanks! Closing.