Bug 1619993 - Use Debugger.Object values consistently across watchpoints. r=jlast

Differential Revision: https://phabricator.services.mozilla.com/D65671

--HG--
extra : moz-landing-system : lando

devtools/client/debugger/test/mochitest/browser_dbg-watchpoints.js

@@ -2,6 +2,10 @@
  * 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/>. */
 
+async function getScopeValue(dbg, index) {
+  return (await waitForElement(dbg, "scopeValue", index)).innerText;
+}
+
 // - Tests adding a watchpoint
 // - Tests removing a watchpoint
 // - Tests adding a watchpoint, resuming to after the youngest frame has popped,
@@ -30,6 +34,7 @@ add_task(async function() {
   await waitForPaused(dbg);
   await waitForState(dbg, () => dbg.selectors.getSelectedInlinePreviews());
   assertPausedAtSourceAndLine(dbg, sourceId, 17);
+  is(await getScopeValue(dbg, 5), "3");
 
   info("Resume and wait to pause at the access to b in the first `obj.b;`");
   resume(dbg);
@@ -62,7 +67,7 @@ add_task(async function() {
   getWatchpointItem2.click();
   pressKey(dbg, "Escape");
   await addedWatchpoint2;
-  
+
   info("Resume and wait to pause at the access to b in getB");
   resume(dbg);
   await waitForPaused(dbg);
@@ -81,7 +86,7 @@ add_task(async function() {
   el2.scrollIntoView();
      clickElementWithSelector(dbg, ".remove-get-watchpoint");
   await removedWatchpoint2;
-   
+
   info("Add back the get watchpoint on b");
   const addedWatchpoint3 = waitForDispatch(dbg, "SET_WATCHPOINT");
   await rightClickScopeNode(dbg, 5);

devtools/server/actors/object.js

@@ -780,9 +780,7 @@ const proto = {
       retval.value = this.hooks.createValueGrip(desc.value);
     } else if (this.thread.getWatchpoint(obj, name.toString())) {
       const watchpoint = this.thread.getWatchpoint(obj, name.toString());
-      retval.value = this.hooks.createValueGrip(
-        this.obj.makeDebuggeeValue(watchpoint.desc.value)
-      );
+      retval.value = this.hooks.createValueGrip(watchpoint.desc.value);
       retval.watchpoint = watchpoint.watchpointType;
     } else {
       if ("get" in desc) {

devtools/server/actors/utils/watchpoint-map.js

@@ -10,28 +10,33 @@ class WatchpointMap {
     this._watchpoints = new Map();
   }
 
-  setWatchpoint(objActor, data) {
+  _setWatchpoint(objActor, data) {
     const { property, label, watchpointType } = data;
     const obj = objActor.rawValue();
 
-    if (this.has(obj, property)) {
-      return;
+    const desc = objActor.obj.getOwnPropertyDescriptor(property);
+
+    if (this.has(obj, property) || desc.set || desc.get || !desc.configurable) {
+      return null;
     }
 
-    const desc =
-      Object.getOwnPropertyDescriptor(obj, property) ||
-      objActor.obj.getOwnPropertyDescriptor(property);
-
-    if (desc.set || desc.get || !desc.configurable) {
-      return;
+    function getValue() {
+      return typeof desc.value === "object" && desc.value
+        ? desc.value.unsafeDereference()
+        : desc.value;
     }
-
-    const pauseAndRespond = type => {
+    function setValue(v) {
+      desc.value = objActor.obj.makeDebuggeeValue(v);
+    }
+    const maybeHandlePause = type => {
       const frame = this.thread.dbg.getNewestFrame();
-      this.thread._pauseAndRespond(frame, {
-        type: type,
-        message: label,
-      });
+
+      if (this.thread.hasMoved(frame, type) && !this.thread.skipBreakpoints) {
+        this.thread._pauseAndRespond(frame, {
+          type: type,
+          message: label,
+        });
+      }
     };
 
     if (watchpointType === "get") {
@@ -39,20 +44,11 @@ class WatchpointMap {
         configurable: desc.configurable,
         enumerable: desc.enumerable,
         set: objActor.obj.makeDebuggeeValue(v => {
-          desc.value = v;
+          setValue(v);
         }),
         get: objActor.obj.makeDebuggeeValue(() => {
-          const frame = this.thread.dbg.getNewestFrame();
-
-          if (!this.thread.hasMoved(frame, "getWatchpoint")) {
-            return false;
-          }
-
-          if (!this.thread.skipBreakpoints) {
-            pauseAndRespond("getWatchpoint");
-          }
-
-          return desc.value;
+          maybeHandlePause("getWatchpoint");
+          return getValue();
         }),
       });
     }
@@ -62,31 +58,25 @@ class WatchpointMap {
         configurable: desc.configurable,
         enumerable: desc.enumerable,
         set: objActor.obj.makeDebuggeeValue(v => {
-          const frame = this.thread.dbg.getNewestFrame();
-
-          if (!this.thread.hasMoved(frame, "setWatchpoint")) {
-            desc.value = v;
-            return;
-          }
-
-          if (!this.thread.skipBreakpoints) {
-            pauseAndRespond("setWatchpoint");
-          }
-
-          desc.value = v;
+          maybeHandlePause("setWatchpoint");
+          setValue(v);
         }),
         get: objActor.obj.makeDebuggeeValue(() => {
-          return desc.value;
+          return getValue();
         }),
       });
     }
+
+    return desc;
   }
 
   add(objActor, data) {
     // Get the object's description before calling setWatchpoint,
     // otherwise we'll get the modified property descriptor instead
-    const desc = objActor.obj.getOwnPropertyDescriptor(data.property);
-    this.setWatchpoint(objActor, data);
+    const desc = this._setWatchpoint(objActor, data);
+    if (!desc) {
+      return;
+    }
 
     const objWatchpoints =
       this._watchpoints.get(objActor.rawValue()) || new Map();