Bug 1684857 - [devtools] Export current DAMP runner from damp.js r=ochameau,perftest-reviewers,kimberlythegeek

Depends on D97733

Exporting the current DAMP runner as a singleton from damp.js simplifies the dependency management between damp.js and head.js

Differential Revision: https://phabricator.services.mozilla.com/D100670

testing/talos/talos/tests/devtools/addon/api.js

@@ -54,9 +54,8 @@ this.damp = class extends ExtensionAPI {
           loader.loader.globals.rootURI = rootURI;
           loader.loader.globals.dampWindow = context.appWindow;
 
-          dump("[damp-api] Instanciate the DAMP runner and start the test\n");
-          const { Damp } = require("damp-test/damp");
-          const damp = new Damp();
+          dump("[damp-api] Retrieve the DAMP runner and start the test\n");
+          const { damp } = require("damp-test/damp");
           return damp.startTest();
         },
       },

testing/talos/talos/tests/devtools/addon/content/damp.js

@@ -19,7 +19,6 @@ const Services = require("Services");
 const { AddonManager } = require("resource://gre/modules/AddonManager.jsm");
 
 const DampLoadParentModule = require("damp-test/actors/DampLoadParent.jsm");
-const dampTestHead = require("damp-test/tests/head.js");
 const DAMP_TESTS = require("damp-test/damp-tests.js");
 
 const env = Cc["@mozilla.org/process/environment;1"].getService(
@@ -245,9 +244,6 @@ Damp.prototype = {
   // Name of the test currently executed (i.e. path from /tests folder)
   _currentTest: null,
 
-  // Is DAMP finished executing? Help preventing async execution when DAMP had an error
-  _done: false,
-
   _runNextTest() {
     clearTimeout(this._timeout);
 
@@ -340,6 +336,7 @@ Damp.prototype = {
 
   _doneInternal() {
     // Ignore any duplicated call to this method
+    // Call startTest() again in order to reset this flag.
     if (this._done) {
       return;
     }
@@ -438,8 +435,8 @@ Damp.prototype = {
     });
 
     try {
-      dump("Initialize the head file with a reference to this DAMP instance\n");
-      dampTestHead.initialize(this);
+      // Is DAMP finished executing? Help preventing async execution when DAMP had an error
+      this._done = false;
 
       this._registerDampLoadActors();
 
@@ -538,4 +535,4 @@ Damp.prototype = {
   },
 };
 
-exports.Damp = Damp;
+exports.damp = new Damp();

testing/talos/talos/tests/devtools/addon/content/tests/head.js

@@ -31,13 +31,7 @@ exports.SIMPLE_URL = PAGES_BASE_URL + "simple.html";
 exports.COMPLICATED_URL =
   "http://www.bild.de-talos/fis/tp5n/bild.de/www.bild.de/index.html";
 
-let damp = null;
-/*
- * This method should be called by js before starting the tests.
- */
-exports.initialize = function(_damp) {
-  damp = _damp;
-};
+const { damp } = require("damp-test/damp");
 
 function garbageCollect() {
   return damp.garbageCollect();