Consistently prefer assert.lengthOf to check array-like lengths.

In our tests, we should stick to ideally just one way of asserting
array-like lengths, `assert.lengthOf`, and avoid any kind of
combinations `assert.equal`,`assert.strictEqual`, `assert.deepEqual`,
or `assert.deepStrictEqual`.

Bug: 386335487
Change-Id: I8f88e214acdae0c6e34dbb169c62ebc9a80317af
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6113832
Reviewed-by: Changhao Han <changhaohan@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>

Author: bmeurer

.eslintrc.js

@@ -292,11 +292,12 @@ module.exports = {
       'mocha/no-nested-tests': 'error',
 
       'rulesdir/check-test-definitions' : 'error',
+      'rulesdir/compare-arrays-with-assert-deepequal' : 'error',
       'rulesdir/no-assert-equal' : 'error',
       'rulesdir/no-assert-deep-strict-equal' : 'error',
       'rulesdir/no-repeated-tests' : 'error',
-      'rulesdir/compare-arrays-with-assert-deepequal' : 'error',
       'rulesdir/no-screenshot-test-outside-perf-panel' : 'error',
+      'rulesdir/prefer-assert-length-of' : 'error',
       'rulesdir/trace-engine-test-timeouts' : 'error',
       '@typescript-eslint/no-non-null-assertion' : 'off',
     },

front_end/core/common/Console.test.ts

@@ -25,7 +25,7 @@ describe('Console', () => {
       console.addMessage('Bar', Common.Console.MessageLevel.ERROR, true);
       console.addMessage('Donkey', Common.Console.MessageLevel.INFO, true);
       const messages = console.messages();
-      assert.strictEqual(messages.length, 4);
+      assert.lengthOf(messages, 4);
     });
 
     it('dispatches events to listeners', done => {

front_end/core/common/SettingRegistration.test.ts

@@ -70,10 +70,8 @@ describe('SettingRegistration', () => {
     const enableSettingCommands = allCommands.filter(
         command => command.title === enableTitle &&
             command.category === Common.Settings.getLocalizedSettingsCategory(settingCategory));
-    assert.strictEqual(
-        disableSettingCommands.length, 1, 'Commands for changing a setting\'s value were not added correctly');
-    assert.strictEqual(
-        enableSettingCommands.length, 1, 'Commands for changing a setting\'s value were not added correctly');
+    assert.lengthOf(disableSettingCommands, 1, 'Commands for changing a setting\'s value were not added correctly');
+    assert.lengthOf(enableSettingCommands, 1, 'Commands for changing a setting\'s value were not added correctly');
   });
 
   it('triggers a setting\'s change listener when a setting is set', () => {

front_end/core/platform/TypedArrayUtilities.test.ts

@@ -8,25 +8,25 @@ describe('TypedArrayUtilities', () => {
   describe('BigUint32Array', () => {
     it('can be expandable', () => {
       const array = Platform.TypedArrayUtilities.createExpandableBigUint32Array();
-      assert.strictEqual(array.length, 0);
+      assert.lengthOf(array, 0);
       array.setValue(0, 33);
       array.setValue(1, 44);
-      assert.strictEqual(array.length, 2);
+      assert.lengthOf(array, 2);
       assert.strictEqual(array.getValue(0), 33);
       assert.strictEqual(array.getValue(1), 44);
       assert.strictEqual(array.asArrayOrFail() as Object, array);
     });
     it('can act as a Uint32Array', () => {
       const array = Platform.TypedArrayUtilities.createFixedBigUint32Array(15);
-      assert.strictEqual(array.length, 15);
+      assert.lengthOf(array, 15);
       assert.strictEqual(array.getValue(7), 0);
       array.setValue(7, 77);
       assert.strictEqual(array.getValue(7), 77);
       assert.strictEqual(array.asUint32ArrayOrFail() as Object, array);
     });
     it('can be bigger than a Uint32Array', () => {
       const array = Platform.TypedArrayUtilities.createFixedBigUint32Array(12_345_678, /* maxLengthForTesting=*/ 2e6);
-      assert.strictEqual(array.length, 12_345_678);
+      assert.lengthOf(array, 12_345_678);
       assert.strictEqual(array.getValue(0), 0);
       assert.strictEqual(array.getValue(500_000), 0);
       assert.strictEqual(array.getValue(5_000_000), 0);

front_end/core/sdk/CSSStyleDeclaration.test.ts

@@ -249,7 +249,7 @@ describeWithMockConnection('CSSStyleDeclaration', () => {
 
     const style = new SDK.CSSStyleDeclaration.CSSStyleDeclaration(
         cssModel, null, stubCSSStyle, SDK.CSSStyleDeclaration.Type.Regular);
-    assert.strictEqual(style.allProperties().length, 1);
+    assert.lengthOf(style.allProperties(), 1);
     assertPropertValues(style.allProperties()[0], [
       ['name', '-webkit-background-clip'],
       ['value', 'border-box'],

front_end/core/sdk/ChildTargetManager.test.ts

@@ -36,17 +36,17 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('adds subtargets', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget(
         {sessionId: createSessionId(), targetInfo: createTargetInfo(TARGET_ID), waitingForDebugger: false});
-    assert.strictEqual(childTargetManager.childTargets().length, 1);
+    assert.lengthOf(childTargetManager.childTargets(), 1);
     assert.strictEqual(childTargetManager.childTargets()[0].id(), TARGET_ID);
   });
 
   it('sets subtarget type', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     for (const [protocolType, sdkType] of [
              ['iframe', SDK.Target.Type.FRAME],
              ['webview', SDK.Target.Type.FRAME],
@@ -73,7 +73,7 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('sets subtarget to frame for devtools scheme if type is other', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget({
       sessionId: createSessionId(),
       targetInfo: createTargetInfo(undefined, 'other', 'devtools://foo/bar'),
@@ -94,7 +94,7 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('sets subtarget to frame for chrome://print/ if type is other', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget({
       sessionId: createSessionId(),
       targetInfo: createTargetInfo(undefined, 'other', 'chrome://print/'),
@@ -107,7 +107,7 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('sets subtarget to frame for chrome://file-manager/ if type is other', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget({
       sessionId: createSessionId(),
       targetInfo: createTargetInfo(undefined, 'other', 'chrome://file-manager/?%7B%22allowedPaths%22:%22anyPathOrUrl'),
@@ -120,7 +120,7 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('sets subtarget to frame for sidebar URLs if type is other', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget({
       sessionId: createSessionId(),
       targetInfo: createTargetInfo(undefined, 'other', 'chrome://read-later.top-chrome/'),
@@ -141,7 +141,7 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('sets worker target name to the target title', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget({
       sessionId: createSessionId(),
       targetInfo: createTargetInfo(undefined, 'worker', 'http://example.com/worker.js', TITLE),
@@ -153,7 +153,7 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('sets non-frame target name to the last path component if present', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget({
       sessionId: createSessionId(),
       targetInfo: createTargetInfo(undefined, 'service_worker', 'http://example.org/service_worker.html', TITLE),
@@ -171,7 +171,7 @@ describeWithMockConnection('ChildTargetManager', () => {
   it('sets non-frame target a numbered name if it cannot use URL path', async () => {
     const target = createTarget();
     const childTargetManager = new SDK.ChildTargetManager.ChildTargetManager(target);
-    assert.strictEqual(childTargetManager.childTargets().length, 0);
+    assert.lengthOf(childTargetManager.childTargets(), 0);
     await childTargetManager.attachedToTarget({
       sessionId: createSessionId(),
       targetInfo: createTargetInfo(undefined, 'page', 'data:text/html,<!doctype html>'),

front_end/core/sdk/EnhancedTracesParser.test.ts

@@ -143,7 +143,7 @@ describe('EnhancedTracesParser', () => {
         assert.deepEqual(target, target2);
       }
     }
-    assert.strictEqual(targets.length, 2);
+    assert.lengthOf(targets, 2);
   });
 
   it('captures execution context info', async function() {
@@ -157,7 +157,7 @@ describe('EnhancedTracesParser', () => {
         assert.fail('Contexts and Scripts should not be null or undefined');
       }
     }
-    assert.strictEqual(executionContexts.length, 3);
+    assert.lengthOf(executionContexts, 3);
     for (const executionContext of executionContexts) {
       if (executionContext.id === 1 && executionContext.isolate === '12345') {
         assert.deepEqual(executionContext, executionContext1);
@@ -180,7 +180,7 @@ describe('EnhancedTracesParser', () => {
         assert.fail('Contexts and Scripts should not be null or undefined');
       }
     }
-    assert.strictEqual(scripts.length, 3);
+    assert.lengthOf(scripts, 3);
     for (const script of scripts) {
       if (script.scriptId === '1' && script.isolate === '12345') {
         assert.deepEqual(script, script1);
@@ -200,7 +200,7 @@ describe('EnhancedTracesParser', () => {
         const executionContexts = contextsAndScripts[0];
         const scripts = contextsAndScripts[1];
         if (target.pid === 8050) {
-          assert.strictEqual(executionContexts.length, 2);
+          assert.lengthOf(executionContexts, 2);
           for (const executionContext of executionContexts) {
             // We should be able to get the correct execution context without specifying isolate
             // as the contexts and scripts are grouped under its repsective target already.
@@ -210,7 +210,7 @@ describe('EnhancedTracesParser', () => {
               assert.deepEqual(executionContext, executionContext2);
             }
           }
-          assert.strictEqual(scripts.length, 2);
+          assert.lengthOf(scripts, 2);
           for (const script of scripts) {
             if (script.scriptId === '1') {
               assert.deepEqual(script, script1);
@@ -219,8 +219,8 @@ describe('EnhancedTracesParser', () => {
             }
           }
         } else if (target.pid === 8051) {
-          assert.strictEqual(executionContexts.length, 1);
-          assert.strictEqual(scripts.length, 1);
+          assert.lengthOf(executionContexts, 1);
+          assert.lengthOf(scripts, 1);
           assert.deepEqual(executionContexts[0], executionContext3);
           assert.deepEqual(scripts[0], script3);
         }

front_end/core/sdk/NetworkManager.test.ts

@@ -37,7 +37,7 @@ describeWithMockConnection('MultitargetNetworkManager', () => {
           {requestId: 'mockId', request: {url: 'example.com'}} as Protocol.Network.RequestWillBeSentEvent);
 
       // 3) Check that the resulting NetworkRequest has the Trust Token Event data associated with it.
-      assert.strictEqual(startedRequests.length, 1);
+      assert.lengthOf(startedRequests, 1);
       assert.strictEqual(startedRequests[0].trustTokenOperationDoneEvent(), mockEvent);
     });
   });

front_end/core/sdk/NetworkRequest.test.ts

@@ -34,7 +34,7 @@ describe('NetworkRequest', () => {
       responseHeaders: [{name: 'Set-Cookie', value: 'foo=bar'}, {name: 'Set-Cookie', value: 'baz=qux'}],
       resourceIPAddressSpace: 'Public' as Protocol.Network.IPAddressSpace,
     } as unknown as SDK.NetworkRequest.ExtraResponseInfo);
-    assert.strictEqual(request.responseCookies.length, 2);
+    assert.lengthOf(request.responseCookies, 2);
     expectCookie(request.responseCookies[0], {name: 'foo', value: 'bar', size: 8});
     expectCookie(request.responseCookies[1], {name: 'baz', value: 'qux', size: 7});
   });
@@ -89,7 +89,7 @@ describe('NetworkRequest', () => {
       resourceIPAddressSpace: 'Public' as Protocol.Network.IPAddressSpace,
       cookiePartitionKey: {topLevelSite: 'partitionKey', hasCrossSiteAncestor: false},
     } as unknown as SDK.NetworkRequest.ExtraResponseInfo);
-    assert.strictEqual(request.responseCookies.length, 2);
+    assert.lengthOf(request.responseCookies, 2);
     expectCookie(request.responseCookies[0], {name: 'foo', value: 'bar', size: 8});
     expectCookie(request.responseCookies[1], {
       name: 'baz',

front_end/core/sdk/RehydratingConnection.test.ts

@@ -136,7 +136,7 @@ describe('RehydratingSession', () => {
       method: 'Debugger.enable',
       sessionId,
     });
-    assert.strictEqual(mockRehydratingConnection.messageQueue.length, 3);
+    assert.lengthOf(mockRehydratingConnection.messageQueue, 3);
     const scriptParsedMessages = mockRehydratingConnection.messageQueue.slice(0, 2);
     const resultMessage = mockRehydratingConnection.messageQueue.slice(2);
     for (const scriptParsedMessage of scriptParsedMessages) {
@@ -155,7 +155,7 @@ describe('RehydratingSession', () => {
       method: 'Runtime.enable',
       sessionId,
     });
-    assert.strictEqual(mockRehydratingConnection.messageQueue.length, 3);
+    assert.lengthOf(mockRehydratingConnection.messageQueue, 3);
     const executionContextCreatedMessages = mockRehydratingConnection.messageQueue.slice(0, 2);
     const resultMessage = mockRehydratingConnection.messageQueue.slice(2);
     for (const executionContextCreatedMessage of executionContextCreatedMessages) {
@@ -179,7 +179,7 @@ describe('RehydratingSession', () => {
         scriptId: mockScript1.scriptId,
       },
     });
-    assert.strictEqual(mockRehydratingConnection.messageQueue.length, 1);
+    assert.lengthOf(mockRehydratingConnection.messageQueue, 1);
     const scriptSourceTextMessage = mockRehydratingConnection.messageQueue[0];
     assert.isNotNull(scriptSourceTextMessage);
     assert.strictEqual(scriptSourceTextMessage.id, messageId);