Bug 1695744 - [devtools] Use a DescriptorMixin in order to share a common interface between all descriptor fronts. r=jdescottes

This will help expose getCommands method in the next patch.

Differential Revision: https://phabricator.services.mozilla.com/D105610

devtools/client/fronts/descriptors/descriptor-mixin.js

@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * A Descriptor represents a debuggable context. It can be a browser tab, a tab on
+ * a remote device, like a tab on Firefox for Android. But it can also be an add-on,
+ * as well as firefox parent process, or just one of its content process.
+ * It can be very similar to a Target. The key difference is the lifecycle of these two classes.
+ * The descriptor is meant to be always alive and meaningful/usable until the end of the RDP connection.
+ * Typically a Tab Descriptor will describe the tab and not the one document currently loaded in this tab,
+ * while the Target, will describe this one document and a new Target may be created on each navigation.
+ */
+function DescriptorMixin(parentClass) {
+  class Descriptor extends parentClass {
+    constructor(client, targetFront, parentFront) {
+      super(client, targetFront, parentFront);
+
+      this._client = client;
+    }
+
+    get client() {
+      return this._client;
+    }
+  }
+  return Descriptor;
+}
+exports.DescriptorMixin = DescriptorMixin;

devtools/client/fronts/descriptors/moz.build

@@ -5,6 +5,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DevToolsModules(
+    "descriptor-mixin.js",
     "process.js",
     "tab.js",
     "webextension.js",

devtools/client/fronts/descriptors/process.js

@@ -16,18 +16,18 @@ const {
   FrontClassWithSpec,
   registerFront,
 } = require("devtools/shared/protocol");
+const {
+  DescriptorMixin,
+} = require("devtools/client/fronts/descriptors/descriptor-mixin");
 
-class ProcessDescriptorFront extends FrontClassWithSpec(processDescriptorSpec) {
+class ProcessDescriptorFront extends DescriptorMixin(
+  FrontClassWithSpec(processDescriptorSpec)
+) {
   constructor(client, targetFront, parentFront) {
     super(client, targetFront, parentFront);
     this.isParent = false;
     this._processTargetFront = null;
     this._targetFrontPromise = null;
-    this._client = client;
-  }
-
-  get client() {
-    return this._client;
   }
 
   form(json) {

devtools/client/fronts/descriptors/tab.js

@@ -21,6 +21,9 @@ const {
   FrontClassWithSpec,
   registerFront,
 } = require("devtools/shared/protocol");
+const {
+  DescriptorMixin,
+} = require("devtools/client/fronts/descriptors/descriptor-mixin");
 
 /**
  * DescriptorFront for tab targets.
@@ -30,10 +33,11 @@ const {
  *        TODO: This event could move to the server in order to support
  *        remoteness change for remote debugging.
  */
-class TabDescriptorFront extends FrontClassWithSpec(tabDescriptorSpec) {
+class TabDescriptorFront extends DescriptorMixin(
+  FrontClassWithSpec(tabDescriptorSpec)
+) {
   constructor(client, targetFront, parentFront) {
     super(client, targetFront, parentFront);
-    this._client = client;
 
     // The tab descriptor can be configured to create either local tab targets
     // (eg, regular tab toolbox) or browsing context targets (eg tab remote
@@ -48,10 +52,6 @@ class TabDescriptorFront extends FrontClassWithSpec(tabDescriptorSpec) {
     this._handleTabEvent = this._handleTabEvent.bind(this);
   }
 
-  get client() {
-    return this._client;
-  }
-
   form(json) {
     this.actorID = json.actor;
     this._form = json;

devtools/client/fronts/descriptors/webextension.js

@@ -10,6 +10,9 @@ const {
   FrontClassWithSpec,
   registerFront,
 } = require("devtools/shared/protocol");
+const {
+  DescriptorMixin,
+} = require("devtools/client/fronts/descriptors/descriptor-mixin");
 loader.lazyRequireGetter(
   this,
   "BrowsingContextTargetFront",
@@ -17,17 +20,13 @@ loader.lazyRequireGetter(
   true
 );
 
-class WebExtensionDescriptorFront extends FrontClassWithSpec(
-  webExtensionDescriptorSpec
+class WebExtensionDescriptorFront extends DescriptorMixin(
+  FrontClassWithSpec(webExtensionDescriptorSpec)
 ) {
   constructor(client, targetFront, parentFront) {
     super(client, targetFront, parentFront);
-    this._client = client;
     this.traits = {};
   }
-  get client() {
-    return this._client;
-  }
 
   form(json) {
     this.actorID = json.actor;

devtools/client/fronts/descriptors/worker.js

@@ -12,13 +12,15 @@ const {
   registerFront,
 } = require("devtools/shared/protocol");
 const { TargetMixin } = require("devtools/client/fronts/targets/target-mixin");
+const {
+  DescriptorMixin,
+} = require("devtools/client/fronts/descriptors/descriptor-mixin");
 
-class WorkerDescriptorFront extends TargetMixin(
-  FrontClassWithSpec(workerDescriptorSpec)
+class WorkerDescriptorFront extends DescriptorMixin(
+  TargetMixin(FrontClassWithSpec(workerDescriptorSpec))
 ) {
   constructor(client, targetFront, parentFront) {
     super(client, targetFront, parentFront);
-    this._client = client;
 
     this.traits = {};
 
@@ -30,10 +32,6 @@ class WorkerDescriptorFront extends TargetMixin(
     this.once("worker-close", this.destroy.bind(this));
   }
 
-  get client() {
-    return this._client;
-  }
-
   form(json) {
     this.actorID = json.actor;
     this.id = json.id;