Repos should identify when they support the output-js task family

[samreid]

To support #1073 and perennial tools, we would like repos to identify when they support an output-js task. @jonathanolson and I discussed adding a package.json flag like so:

"phet":{
    "supportsOutputJS": true
}

We will need to mark this in many repos and will have problems if one is forgotten. Also, @jonathanolson what do you think about running grunt --help in a repo to see if it outputs a task name? That seems like less we have to maintain and less chances to get things wrong (unless the task name accidentally appears in the documentation), but it is also less direct and takes longer to compute each time (from grunt startup overhead, around 1 second on my side).

@jonathanolson we discussed adding the supportsOutputJS flag, but I wanted to get your opinion on that vs using grunt --help or something like that before I proceed. Can you please advise and reassign to me?

Here is my partial patch in case we proceed with the flag:

Index: main/perennial/js/common/ChipperVersion.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/main/perennial/js/common/ChipperVersion.js b/main/perennial/js/common/ChipperVersion.js
--- a/main/perennial/js/common/ChipperVersion.js	(revision 80d39e584823cfd631fe4572f26da2b0eb77928a)
+++ b/main/perennial/js/common/ChipperVersion.js	(date 1631309724317)
@@ -16,9 +16,9 @@
    * @param {number} major - The major part of the version (the 3 in 3.1.2)
    * @param {number} minor - The minor part of the version (the 1 in 3.1.2)
    * @param {number} maintenance - The maintenance part of the version (the 2 in 3.1.2)
-   * @param {boolean} outputJS - Flag that indicates whether grunt suppports the commands `output-js` and `output-js-all`
+   * @param {boolean} chipperSupportsOutputJSGruntTasks - Flag that indicates whether grunt suppports the family of commands `output-js` `output-js-project` and `output-js-all`
    */
-  function ChipperVersion( major, minor, maintenance, outputJS ) {
+  function ChipperVersion( major, minor, maintenance, chipperSupportsOutputJSGruntTasks ) {
 
     assert( typeof major === 'number' && major >= 0 && major % 1 === 0, 'major version should be a non-negative integer' );
     assert( typeof minor === 'number' && minor >= 0 && minor % 1 === 0, 'minor version should be a non-negative integer' );
@@ -28,7 +28,7 @@
     this.major = major;
     this.minor = minor;
     this.maintenance = maintenance;
-    this.outputJS = outputJS;
+    this.chipperSupportsOutputJSGruntTasks = chipperSupportsOutputJSGruntTasks;
   }
 
   // Can't rely on inherit existing
@@ -66,9 +66,9 @@
     const major = parseInt( matches[ 1 ], 10 );
     const minor = parseInt( matches[ 2 ], 10 );
     const maintenance = parseInt( matches[ 3 ], 10 );
-    const outputJS = packageJSON.phet && packageJSON.phet.outputJS;
+    const chipperSupportsOutputJSGruntTasks = packageJSON.phet && packageJSON.phet.chipperSupportsOutputJSGruntTasks;
 
-    return new ChipperVersion( major, minor, maintenance, outputJS );
+    return new ChipperVersion( major, minor, maintenance, chipperSupportsOutputJSGruntTasks );
   };
 
   return ChipperVersion;
Index: main/gravity-and-orbits/package.json
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/main/gravity-and-orbits/package.json b/main/gravity-and-orbits/package.json
--- a/main/gravity-and-orbits/package.json	(revision 70c8bfd8821b6dcafa0a929ca2186fcd512cc72c)
+++ b/main/gravity-and-orbits/package.json	(date 1631289405789)
@@ -25,7 +25,8 @@
     "phet-io": {
       "compareDesignedAPIChanges": true
     },
-    "typescript": true
+    "typescript": true,
+    "supportsOutputJS": true
   },
   "eslintConfig": {
     "extends": "../chipper/eslint/sim_eslintrc.js"
Index: main/perennial/js/common/outputJS.js
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/main/perennial/js/common/outputJS.js b/main/perennial/js/common/outputJS.js
--- a/main/perennial/js/common/outputJS.js	(revision 80d39e584823cfd631fe4572f26da2b0eb77928a)
+++ b/main/perennial/js/common/outputJS.js	(date 1631310858353)
@@ -8,28 +8,44 @@
  */
 
 const execute = require( '../dual/execute' );
+const fs = require( 'fs' );
 const gruntCommand = require( '../common/gruntCommand' );
 const winston = require( 'winston' );
 const ChipperVersion = require( '../common/ChipperVersion' );
+const loadJSON = require( '../common/loadJSON' );
 
 /**
  * Outputs JS for a directory
  * @public
  *
- * @param {string} cwd
+ * @param {string} repo
  * @returns {Promise}
  */
-module.exports = async function( cwd ) {
+module.exports = async function( repo ) {
 
   winston.info( 'running outputJS' );
 
   const chipperVersion = ChipperVersion.getFromRepository();
 
-  if ( chipperVersion.outputJS ) {
-    winston.info( 'running grunt output-js' );
-    await execute( gruntCommand, [ 'output-js' ], cwd );
+  let ranOutputJS = false;
+
+  // Not every version of chipper has the output-js task family.  Only proceed if it exists in this version of chipper.
+  if ( chipperVersion.chipperSupportsOutputJSGruntTasks ) {
+
+    const packageFilePath = `../${repo}/package.json`;
+    const exists = fs.existsSync( packageFilePath );
+    if ( exists ) {
+      const packageObject = await loadJSON( packageFilePath );
+
+      // Not every repo supports the output-js task, only proceed if it is supported
+      if ( packageObject.phet && packageObject.phet.supportsOutputJS ) {
+        winston.info( 'running grunt output-js' );
+        await execute( gruntCommand, [ 'output-js' ], `../${repo}` );
+        ranOutputJS = true;
+      }
+    }
   }
-  else {
+  if ( !ranOutputJS ) {
     winston.info( 'outputJS not detected, skipping...' );
   }
 };
\ No newline at end of file
Index: main/chipper/package.json
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/main/chipper/package.json b/main/chipper/package.json
--- a/main/chipper/package.json	(revision 095967ac58bc0b0e9ee7a2501c0d6c8ce40f1bac)
+++ b/main/chipper/package.json	(date 1631289981858)
@@ -7,7 +7,8 @@
     "url": "https://github.com/phetsims/chipper.git"
   },
   "phet": {
-    "outputJS": true
+    "chipperSupportsOutputJSGruntTasks": true,
+    "supportsOutputJS": true
   },
   "devDependencies": {
     "@babel/core": "^7.15.0",

[samreid]

@zepumph and I discussed it and agreed to move forward with the package.json flag. Self-assigning to add the flag to all appropriate repos.

[samreid]

Pushed, re-closing.