DevTools: [Persistence] validate persistence binding.

third_party/WebKit/Source/devtools/front_end/persistence/Persistence.js

Index: third_party/WebKit/Source/devtools/front_end/persistence/Persistence.js
diff --git a/third_party/WebKit/Source/devtools/front_end/persistence/Persistence.js b/third_party/WebKit/Source/devtools/front_end/persistence/Persistence.js
index a67fd69013a738f2c74b04e11dd477ea68d948c7..09adad84d5e5254c64db5994052b3be98e20650d 100644
--- a/third_party/WebKit/Source/devtools/front_end/persistence/Persistence.js
+++ b/third_party/WebKit/Source/devtools/front_end/persistence/Persistence.js
@@ -32,19 +32,71 @@ Persistence.Persistence = class extends Common.Object {
    * @param {!Persistence.PersistenceBinding} binding
    */
   _onBindingCreated(binding) {
-    if (binding.network.isDirty()) {
-      Common.console.log(
-          Common.UIString('%s can not be persisted to file system due to unsaved changes.', binding.network.name()));
+    if (!binding.network.contentLoaded() && !binding.fileSystem.contentLoaded() && !binding.network.isDirty() &&
+        !binding.fileSystem.isDirty()) {
+      this._establishBinding(binding);
       return;
     }
-    if (binding.fileSystem.isDirty())
-      binding.network.setWorkingCopy(binding.fileSystem.workingCopy());
 
+    if (binding[Persistence.Persistence._prevalidatePromise])
+      return;
+    var promise = this._validateBinding(binding).then(onBindingValidated.bind(this));
+    binding[Persistence.Persistence._prevalidatePromise] = promise;
+
+    /**
+     * @this {Persistence.Persistence}
+     */
+    function onBindingValidated(isValid) {

[dgozman, 2016/12/07 01:45:41]

@param

+      if (binding[Persistence.Persistence._prevalidatePromise] !== promise)
+        return;
+      binding[Persistence.Persistence._prevalidatePromise] = null;
+
+      if (isValid)
+        this._establishBinding(binding);
+      else
+        this._prevalidationFailedForTest(binding);
+    }
+  }
+
+  /**
+   * @param {!Persistence.PersistenceBinding} binding
+   */
+  _prevalidationFailedForTest(binding) {
+  }
+
+  /**
+   * @param {!Persistence.PersistenceBinding} binding

[dgozman, 2016/12/07 01:45:41]

@return promise.....

+   */
+  _validateBinding(binding) {
+    return Promise.all([binding.network.requestContent(), binding.fileSystem.requestContent()]).then(onContentsLoaded);
+
+    function onContentsLoaded() {

[dgozman, 2016/12/07 01:45:41]

@return boolean

+      var target = Bindings.NetworkProject.targetForUISourceCode(binding.network);
+      if (target.isNodeJS()) {
+        var fileSystemContent = binding.fileSystem.workingCopy();
+        var networkContent = binding.network.workingCopy();
+        var rewrappedNetworkContent = Persistence.Persistence._rewrapNodeJSContent(
+            binding, binding.fileSystem, fileSystemContent, networkContent);
+        return fileSystemContent === rewrappedNetworkContent;
+      }
+      // Trim trailing whitespaces because V8 adds trailing newline.
+      var fileSystemContent = binding.fileSystem.workingCopy().replace(/\s*$/, '');

[dgozman, 2016/12/07 01:45:41]

.trimRight()

+      var networkContent = binding.network.workingCopy().replace(/\s*$/, '');
+      return fileSystemContent === networkContent;
+    }
+  }
+
+  /**
+   * @param {!Persistence.PersistenceBinding} binding
+   */
+  _establishBinding(binding) {
     binding.network[Persistence.Persistence._binding] = binding;
     binding.fileSystem[Persistence.Persistence._binding] = binding;
 
     binding.fileSystem.forceLoadOnCheckContent();
 
+    binding.network.addEventListener(Workspace.UISourceCode.Events.ContentLoaded, this._onContentLoaded, this);
+    binding.fileSystem.addEventListener(Workspace.UISourceCode.Events.ContentLoaded, this._onContentLoaded, this);
     binding.network.addEventListener(
         Workspace.UISourceCode.Events.WorkingCopyCommitted, this._onWorkingCopyCommitted, this);
     binding.fileSystem.addEventListener(
@@ -64,9 +116,19 @@ Persistence.Persistence = class extends Common.Object {
    * @param {!Persistence.PersistenceBinding} binding
    */
   _onBindingRemoved(binding) {
+    binding[Persistence.Persistence._postvalidatePromise] = null;
+    if (binding[Persistence.Persistence._prevalidatePromise]) {
+      binding[Persistence.Persistence._prevalidatePromise] = null;
+      return;

[dgozman, 2016/12/07 01:45:41]

Drop this return, and the if.

+    }
+    if (!binding.network[Persistence.Persistence._binding] || !binding.fileSystem[Persistence.Persistence._binding])
+      return;
+
     binding.network[Persistence.Persistence._binding] = null;
     binding.fileSystem[Persistence.Persistence._binding] = null;
 
+    binding.network.removeEventListener(Workspace.UISourceCode.Events.ContentLoaded, this._onContentLoaded, this);
+    binding.fileSystem.removeEventListener(Workspace.UISourceCode.Events.ContentLoaded, this._onContentLoaded, this);
     binding.network.removeEventListener(
         Workspace.UISourceCode.Events.WorkingCopyCommitted, this._onWorkingCopyCommitted, this);
     binding.fileSystem.removeEventListener(
@@ -85,6 +147,29 @@ Persistence.Persistence = class extends Common.Object {
   /**
    * @param {!Common.Event} event
    */
+  _onContentLoaded(event) {
+    var uiSourceCode = /** @type {!Workspace.UISourceCode} */ (event.target);
+    var binding = uiSourceCode[Persistence.Persistence._binding];
+    if (!binding || binding[Persistence.Persistence._postvalidatePromise])
+      return;
+    var promise = this._validateBinding(binding).then(onBindingValidated.bind(this));
+    binding[Persistence.Persistence._postvalidatePromise] = promise;
+
+    /**
+     * @this {Persistence.Persistence}
+     */
+    function onBindingValidated(isValid) {
+      if (binding[Persistence.Persistence._postvalidatePromise] !== promise)
+        return;
+      binding[Persistence.Persistence._postvalidatePromise] = null;
+      if (!isValid)
+        this._onBindingRemoved(binding);
+    }
+  }
+
+  /**
+   * @param {!Common.Event} event
+   */
   _onWorkingCopyChanged(event) {
     var uiSourceCode = /** @type {!Workspace.UISourceCode} */ (event.target);
     var binding = uiSourceCode[Persistence.Persistence._binding];
@@ -95,7 +180,8 @@ Persistence.Persistence = class extends Common.Object {
     if (target.isNodeJS()) {
       var newContent = uiSourceCode.workingCopy();
       other.requestContent().then(() => {
-        var nodeJSContent = this._rewrapNodeJSContent(binding, other, other.workingCopy(), newContent);
+        var nodeJSContent =
+            Persistence.Persistence._rewrapNodeJSContent(binding, other, other.workingCopy(), newContent);
         setWorkingCopy.call(this, () => nodeJSContent);
       });
       return;
@@ -128,7 +214,7 @@ Persistence.Persistence = class extends Common.Object {
     var target = Bindings.NetworkProject.targetForUISourceCode(binding.network);
     if (target.isNodeJS()) {
       other.requestContent().then(currentContent => {
-        var nodeJSContent = this._rewrapNodeJSContent(binding, other, currentContent, newContent);
+        var nodeJSContent = Persistence.Persistence._rewrapNodeJSContent(binding, other, currentContent, newContent);
         setContent.call(this, nodeJSContent);
       });
       return;
@@ -154,7 +240,7 @@ Persistence.Persistence = class extends Common.Object {
    * @param {string} newContent
    * @return {string}
    */
-  _rewrapNodeJSContent(binding, uiSourceCode, currentContent, newContent) {
+  static _rewrapNodeJSContent(binding, uiSourceCode, currentContent, newContent) {
     if (uiSourceCode === binding.fileSystem) {
       if (newContent.startsWith(Persistence.Persistence._NodePrefix) &&
           newContent.endsWith(Persistence.Persistence._NodeSuffix)) {
@@ -293,5 +379,8 @@ Persistence.PersistenceBinding = class {
   }
 };
 
+Persistence.Persistence._prevalidatePromise = Symbol('Persistence.prevalidatePromise');

[dgozman, 2016/12/07 01:45:41]

Let's have private fields instead.

+Persistence.Persistence._postvalidatePromise = Symbol('Persistence.postvalidatePromise');
+
 /** @type {!Persistence.Persistence} */
 Persistence.persistence;