Bug 1644186 - Add ResourceTransformers. r=ochameau.

Differential Revision: https://phabricator.services.mozilla.com/D81831

devtools/shared/resources/moz.build

@@ -5,6 +5,7 @@
 DIRS += [
     'legacy-listeners',
     'legacy-target-watchers',
+    'transformers',
 ]
 
 DevToolsModules(

devtools/shared/resources/resource-watcher.js

@@ -9,14 +9,6 @@ const EventEmitter = require("devtools/shared/event-emitter");
 // eslint-disable-next-line mozilla/reject-some-requires
 const { gDevTools } = require("devtools/client/framework/devtools");
 
-// eslint-disable-next-line mozilla/reject-some-requires
-loader.lazyRequireGetter(
-  this,
-  "getAdHocFrontOrPrimitiveGrip",
-  "devtools/client/fronts/object",
-  true
-);
-
 class ResourceWatcher {
   /**
    * This class helps retrieving existing and listening to resources.
@@ -233,19 +225,20 @@ class ResourceWatcher {
    *        which describes the resource.
    */
   _onResourceAvailable(targetFront, resources) {
-    for (const resource of resources) {
+    for (let resource of resources) {
       // Put the targetFront on the resource for easy retrieval.
       if (!resource.targetFront) {
         resource.targetFront = targetFront;
       }
       const { resourceType } = resource;
-      if (resourceType == ResourceWatcher.TYPES.CONSOLE_MESSAGE) {
-        if (Array.isArray(resource.message.arguments)) {
-          // We might need to create fronts for each of the message arguments.
-          resource.message.arguments = resource.message.arguments.map(arg =>
-            getAdHocFrontOrPrimitiveGrip(arg, targetFront)
-          );
-        }
+
+      if (ResourceTransformers[resourceType]) {
+        resource = ResourceTransformers[resourceType]({
+          resource,
+          targetList: this.targetList,
+          targetFront,
+          isFissionEnabledOnContentToolbox: gDevTools.isFissionContentToolboxEnabled(),
+        });
       }
 
       this._availableListeners.emit(resourceType, {
@@ -456,3 +449,12 @@ const LegacyListeners = {
   [ResourceWatcher.TYPES
     .ROOT_NODE]: require("devtools/shared/resources/legacy-listeners/root-node"),
 };
+
+// Optional transformers for each type of resource.
+// Each module added here should be a function that will receive the resource, the target, …
+// and perform some transformation on the resource before it will be emitted.
+// This is a good place to handle backward compatibility and manual resource marshalling.
+const ResourceTransformers = {
+  [ResourceWatcher.TYPES
+    .CONSOLE_MESSAGE]: require("devtools/shared/resources/transformers/console-messages"),
+};

devtools/shared/resources/transformers/console-messages.js

@@ -0,0 +1,23 @@
+/* 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";
+
+// eslint-disable-next-line mozilla/reject-some-requires
+loader.lazyRequireGetter(
+  this,
+  "getAdHocFrontOrPrimitiveGrip",
+  "devtools/client/fronts/object",
+  true
+);
+
+module.exports = function({ resource, targetFront }) {
+  if (Array.isArray(resource.message.arguments)) {
+    // We might need to create fronts for each of the message arguments.
+    resource.message.arguments = resource.message.arguments.map(arg =>
+      getAdHocFrontOrPrimitiveGrip(arg, targetFront)
+    );
+  }
+  return resource;
+};

devtools/shared/resources/transformers/moz.build

@@ -0,0 +1,7 @@
+# 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/.
+
+DevToolsModules(
+    'console-messages.js'
+)