From 8667935bf84f158b2d3c7986384f14a4a28060ea Mon Sep 17 00:00:00 2001
From: Alex Rudenko <alexrudenko@chromium.org>
Date: Tue, 19 May 2026 13:43:05 +0200
Subject: [PATCH] Check node origins in getStyles

Bug: 513772764
Change-Id: Ib56dbb9abb06527627ec08a06d21404052e61f45
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/7857677
Reviewed-by: Nikolay Vitkov <nvitkov@chromium.org>
Commit-Queue: Alex Rudenko <alexrudenko@chromium.org>
---

diff --git a/front_end/models/ai_assistance/agents/StylingAgent.test.ts b/front_end/models/ai_assistance/agents/StylingAgent.test.ts
index 2fd6a96..0e3266b 100644
--- a/front_end/models/ai_assistance/agents/StylingAgent.test.ts
+++ b/front_end/models/ai_assistance/agents/StylingAgent.test.ts
@@ -13,6 +13,7 @@
   updateHostConfig,
 } from '../../../testing/EnvironmentHelpers.js';
 import {SnapshotTester} from '../../../testing/SnapshotTester.js';
+import {createStubbedDomNodeWithModels, getMatchedStyles, ruleMatch} from '../../../testing/StyleHelpers.js';
 import * as AiAssistance from '../ai_assistance.js';
 
 const {StylingAgent, AiAgent} = AiAssistance;
@@ -725,13 +726,242 @@
           createExtensionScope,
           execJs,
         });
-        const responses =
-            await Array.fromAsync(agent.run('test', {selected: new AiAssistance.StylingAgent.NodeContext(element)}));
-        const actionStep = responses.find(response => response.type === AiAssistance.AiAgent.ResponseType.ACTION)!;
-        assert.strictEqual(
-            actionStep.output, 'Error: JavaScript execution that modifies the page is currently disabled.');
+        await Array.fromAsync(agent.run('test', {selected: new AiAssistance.StylingAgent.NodeContext(element)}));
         assert.lengthOf(execJs.getCalls(), 1);
       });
     });
   });
+
+  describe('getStyles', () => {
+    it('successfully returns computed and authored styles', async () => {
+      const {node: resolvedNode, cssModel} = createStubbedDomNodeWithModels({nodeId: 42});
+
+      resolvedNode.ownerDocument = null;
+      element.ownerDocument = null;
+
+      sinon.stub(SDK.DOMModel.DeferredDOMNode.prototype, 'resolvePromise').resolves(resolvedNode);
+
+      const computedStyleMap = new Map([['color', 'red']]);
+      (cssModel.getComputedStyle as sinon.SinonStub).resolves(computedStyleMap);
+
+      const matchedPayload = [ruleMatch('div', {color: 'red'})];
+      const matchedStyles = getMatchedStyles({cssModel, node: resolvedNode, matchedPayload});
+      (cssModel.getMatchedStyles as sinon.SinonStub).resolves(matchedStyles);
+
+      const agent = new StylingAgent.StylingAgent({
+        aidaClient: mockAidaClient([
+          [{
+            functionCalls: [{
+              name: 'getStyles',
+              args: {
+                explanation: 'Get element styles',
+                elements: [42],
+                styleProperties: ['color'],
+              },
+            }],
+            explanation: '',
+          }],
+          [{
+            explanation: 'this is the actual answer',
+          }]
+        ]),
+        createExtensionScope,
+        execJs: sinon.spy(),
+      });
+
+      const responses =
+          await Array.fromAsync(agent.run('test', {selected: new AiAssistance.StylingAgent.NodeContext(element)}));
+      const actionStep = responses.find(response => response.type === AiAssistance.AiAgent.ResponseType.ACTION)!;
+      assert.exists(actionStep);
+      assert.strictEqual(
+          actionStep.output,
+          JSON.stringify(
+              {
+                42: {
+                  computed: {color: 'red'},
+                  authored: {color: 'red'},
+                },
+              },
+              null, 2));
+    });
+
+    it('returns error on origin mismatch', async () => {
+      const {node: resolvedNode} = createStubbedDomNodeWithModels({nodeId: 42});
+
+      element.ownerDocument = {
+        documentURL: 'https://example.com',
+      } as unknown as SDK.DOMModel.DOMDocument;
+
+      resolvedNode.ownerDocument = {
+        documentURL: 'https://another.com',
+      } as unknown as SDK.DOMModel.DOMDocument;
+
+      sinon.stub(SDK.DOMModel.DeferredDOMNode.prototype, 'resolvePromise').resolves(resolvedNode);
+
+      const agent = new StylingAgent.StylingAgent({
+        aidaClient: mockAidaClient([
+          [{
+            functionCalls: [{
+              name: 'getStyles',
+              args: {
+                explanation: 'Get element styles',
+                elements: [42],
+                styleProperties: ['color'],
+              },
+            }],
+            explanation: '',
+          }],
+          [{
+            explanation: 'this is the actual answer',
+          }]
+        ]),
+        createExtensionScope,
+        execJs: sinon.spy(),
+      });
+
+      const responses =
+          await Array.fromAsync(agent.run('test', {selected: new AiAssistance.StylingAgent.NodeContext(element)}));
+      const actionStep = responses.find(response => response.type === AiAssistance.AiAgent.ResponseType.ACTION)!;
+      assert.exists(actionStep);
+      assert.strictEqual(actionStep.output, 'Error: Node does not belong to the current origin.');
+    });
+
+    it('returns error when selected element is missing', async () => {
+      const agent = new StylingAgent.StylingAgent({
+        aidaClient: mockAidaClient([
+          [{
+            functionCalls: [{
+              name: 'getStyles',
+              args: {
+                explanation: 'Get element styles',
+                elements: [42],
+                styleProperties: ['color'],
+              },
+            }],
+            explanation: '',
+          }],
+          [{
+            explanation: 'this is the actual answer',
+          }]
+        ]),
+        createExtensionScope,
+        execJs: sinon.spy(),
+      });
+
+      const responses = await Array.fromAsync(agent.run('test', {selected: null}));
+      const actionStep = responses.find(response => response.type === AiAssistance.AiAgent.ResponseType.ACTION)!;
+      assert.exists(actionStep);
+      assert.strictEqual(actionStep.output, 'Error: Could not find the currently selected element.');
+    });
+
+    it('returns error when target node cannot be resolved', async () => {
+      element.ownerDocument = null;
+
+      sinon.stub(SDK.DOMModel.DeferredDOMNode.prototype, 'resolvePromise').resolves(null);
+
+      const agent = new StylingAgent.StylingAgent({
+        aidaClient: mockAidaClient([
+          [{
+            functionCalls: [{
+              name: 'getStyles',
+              args: {
+                explanation: 'Get element styles',
+                elements: [42],
+                styleProperties: ['color'],
+              },
+            }],
+            explanation: '',
+          }],
+          [{
+            explanation: 'this is the actual answer',
+          }]
+        ]),
+        createExtensionScope,
+        execJs: sinon.spy(),
+      });
+
+      const responses =
+          await Array.fromAsync(agent.run('test', {selected: new AiAssistance.StylingAgent.NodeContext(element)}));
+      const actionStep = responses.find(response => response.type === AiAssistance.AiAgent.ResponseType.ACTION)!;
+      assert.exists(actionStep);
+      assert.strictEqual(actionStep.output, 'Error: Could not find the element with uid=42');
+    });
+
+    it('returns error when computed styles fail', async () => {
+      const {node: resolvedNode, cssModel} = createStubbedDomNodeWithModels({nodeId: 42});
+
+      resolvedNode.ownerDocument = null;
+      element.ownerDocument = null;
+