refactor: replace fixed sleep() with polling helpers in UI tests

Replace 12 fixed sleep() calls with condition-based polling:
- waitForTreeItem / waitForTreeItemGone: poll tree view for item presence
- waitForFileExists / waitForFileGone: poll filesystem for file state
- waitForModalDialog: poll for dialog appearance with graceful fallback
- waitForEditorTitle: poll for editor to show expected file title

This makes tests resilient to CI timing variations instead of relying
on hardcoded delays that may be too short on slow machines.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: wenytang-ms

test/ui/command.test.ts

@@ -152,10 +152,9 @@ describe("Command Tests", function() {
         assert.ok(await inputBox.getPlaceHolder() === "Input the class name", `InputBox "Input the class name" should appear`);
         await inputBox.setText("App2");
         await inputBox.confirm();
-        await sleep(1000);
-        const editor = new TextEditor();
-        await editor.save();
-        assert.ok(await editor.getTitle() === "App2.java", `Editor's title should be "App2.java"`);
+        const editor = await waitForEditorTitle("App2.java");
+        assert.ok(editor, `Editor's title should be "App2.java"`);
+        await editor!.save();
         assert.ok(await fse.pathExists(path.join(currentProjectPath!, "src", "main", "java", "App2.java")), `"App2.java" should be created in correct path`);
     });
 
@@ -172,8 +171,7 @@ describe("Command Tests", function() {
         inputBox = await InputBox.create();
         await inputBox.setText("com.mycompany.app2");
         await inputBox.confirm();
-        await sleep(1000);
-        assert.ok(await fse.pathExists(path.join(currentProjectPath!, "src", "main", "java", "com", "mycompany", "app2")), `New package should be created in correct path`);
+        assert.ok(await waitForFileExists(path.join(currentProjectPath!, "src", "main", "java", "com", "mycompany", "app2")), `New package should be created in correct path`);
     });
 
     (platform() === "darwin" ? it.skip : it)("Test java.view.package.revealInProjectExplorer", async function() {
@@ -209,21 +207,20 @@ describe("Command Tests", function() {
         const inputBox = await InputBox.create();
         await inputBox.setText("AppRenamed");
         await inputBox.confirm();
-        await sleep(1000);
-        const dialog = new ModalDialog();
-        const buttons = await dialog.getButtons();
+        const dialog = await waitForModalDialog();
+        assert.ok(dialog, `Rename confirmation dialog should appear`);
+        const buttons = await dialog!.getButtons();
         for (const button of buttons) {
             if (await button.getText() === "OK") {
                 await button.click();
                 break;
             }
         }
-        await sleep(5000);
+        const editor = await waitForEditorTitle("AppRenamed.java");
+        assert.ok(editor, `Editor's title should be "AppRenamed.java"`);
         // Use command palette to save because the editor input area may not be
         // interactable right after the rename refactoring dialog is dismissed.
         await new Workbench().executeCommand('workbench.action.files.save');
-        const editor = new TextEditor();
-        assert.ok(await editor.getTitle() === "AppRenamed.java", `Editor's title should be "AppRenamed.java"`);
         assert.ok(await section.findItem("AppRenamed"), `Item in Java Project section should be "AppRenamed"`);
     });
 
@@ -242,16 +239,18 @@ describe("Command Tests", function() {
         }
         assert.ok(deleteItem, `"Delete" item should be found`);
         await deleteItem!.click();
-        const dialog = new ModalDialog();
-        const buttons = await dialog.getButtons();
-        for (const button of buttons) {
-            if (await button.getText() === "Move to Recycle Bin") {
-                await button.click();
-                break;
+        const dialog = await waitForModalDialog();
+        if (dialog) {
+            const buttons = await dialog.getButtons();
+            for (const button of buttons) {
+                const text = await button.getText();
+                if (text === "Move to Recycle Bin" || text === "Delete") {
+                    await button.click();
+                    break;
+                }
             }
         }
-        await sleep(1000);
-        assert.ok(!await fse.pathExists(path.join(currentProjectPath!, "src", "main", "java", "AppToDelete.java")), `The source file "AppToDelete.java" should be deleted`);
+        assert.ok(await waitForFileGone(path.join(currentProjectPath!, "src", "main", "java", "AppToDelete.java")), `The source file "AppToDelete.java" should be deleted`);
     });
 
     it("Test change to invisible project", async function() {
@@ -275,16 +274,14 @@ describe("Command Tests", function() {
         const input = await InputBox.create();
         await input.setText(path.join(invisibleProjectPath, "libSource", "simple.jar"));
         await input.confirm();
-        await sleep(5000);
+        await sleep(1000);
         referencedItem = await section.findItem("Referenced Libraries") as TreeItem;
         await referencedItem.expand();
-        let simpleItem = await section.findItem("simple.jar") as TreeItem;
+        let simpleItem = await waitForTreeItem(section, "simple.jar") as TreeItem;
         assert.ok(simpleItem, `Library "simple.jar" should be found`);
         await simpleItem.click();
         await clickActionButton(simpleItem, 'Remove from Project Classpath');
-        await sleep(5000);
-        simpleItem = await section.findItem("simple.jar") as TreeItem;
-        assert.ok(!simpleItem, `Library "simple.jar" should not be found`);
+        assert.ok(await waitForTreeItemGone(section, "simple.jar"), `Library "simple.jar" should not be found`);
     });
 
     it("Test java.project.addLibraryFolders", async function() {
@@ -298,14 +295,13 @@ describe("Command Tests", function() {
             .click(button)
             .keyUp(seleniumWebdriver.Key.ALT)
             .perform();
-        await sleep(5000);
         const input = await InputBox.create();
         await input.setText(path.join(invisibleProjectPath, "libSource"));
         await input.confirm();
-        await sleep(5000);
+        await sleep(1000);
         referencedItem = await section.findItem("Referenced Libraries") as TreeItem;
         await referencedItem.expand();
-        assert.ok(await section.findItem("simple.jar"), `Library "simple.jar" should be found`);
+        assert.ok(await waitForTreeItem(section, "simple.jar"), `Library "simple.jar" should be found`);
     });
 
     it("Test java.project.create", async function() {
@@ -317,17 +313,16 @@ describe("Command Tests", function() {
         const picks = await inputBox.getQuickPicks();
         assert.equal("No build tools", await picks[0].getLabel());
         await picks[0].select();
-        await sleep(3000);
+        await sleep(1000);
         inputBox = await InputBox.create();
         await inputBox.setText(projectFolder);
         await inputBox.confirm();
-        await sleep(3000);
+        await sleep(1000);
         inputBox = await InputBox.create();
         await inputBox.setText(newProjectName);
         await inputBox.confirm();
-        await sleep(5000);
-        assert.ok(await fse.pathExists(path.join(projectFolder, newProjectName, "src", "App.java")), `The template source file should be created`);
-        assert.ok(await fse.pathExists(path.join(projectFolder, newProjectName, "README.md")), `The template README file should be created`);
+        assert.ok(await waitForFileExists(path.join(projectFolder, newProjectName, "src", "App.java")), `The template source file should be created`);
+        assert.ok(await waitForFileExists(path.join(projectFolder, newProjectName, "README.md")), `The template README file should be created`);
     });
 
 
@@ -432,6 +427,72 @@ async function dismissModalDialogIfPresent() {
     }
 }
 
+async function waitForTreeItem(section: ViewSection, label: string, timeoutMs = 15000): Promise<TreeItem | undefined> {
+    const start = Date.now();
+    while (Date.now() - start < timeoutMs) {
+        const item = await section.findItem(label) as TreeItem;
+        if (item) return item;
+        await sleep(1000);
+    }
+    return undefined;
+}
+
+async function waitForTreeItemGone(section: ViewSection, label: string, timeoutMs = 15000): Promise<boolean> {
+    const start = Date.now();
+    while (Date.now() - start < timeoutMs) {
+        const item = await section.findItem(label) as TreeItem;
+        if (!item) return true;
+        await sleep(1000);
+    }
+    return false;
+}
+
+async function waitForFileExists(filePath: string, timeoutMs = 15000): Promise<boolean> {
+    const start = Date.now();
+    while (Date.now() - start < timeoutMs) {
+        if (await fse.pathExists(filePath)) return true;
+        await sleep(1000);
+    }
+    return false;
+}
+
+async function waitForFileGone(filePath: string, timeoutMs = 15000): Promise<boolean> {
+    const start = Date.now();
+    while (Date.now() - start < timeoutMs) {
+        if (!await fse.pathExists(filePath)) return true;
+        await sleep(1000);
+    }
+    return false;
+}
+
+async function waitForModalDialog(timeoutMs = 10000): Promise<ModalDialog | undefined> {
+    const start = Date.now();
+    while (Date.now() - start < timeoutMs) {
+        try {
+            const dialog = new ModalDialog();
+            await dialog.getButtons();
+            return dialog;
+        } catch (_e) {
+            await sleep(500);
+        }
+    }
+    return undefined;
+}
+
+async function waitForEditorTitle(expectedTitle: string, timeoutMs = 15000): Promise<TextEditor | undefined> {
+    const start = Date.now();
+    while (Date.now() - start < timeoutMs) {
+        try {
+            const editor = new TextEditor();
+            if (await editor.getTitle() === expectedTitle) return editor;
+        } catch (_e) {
+            // Editor may not be ready yet
+        }
+        await sleep(1000);
+    }
+    return undefined;
+}
+
 async function ensureExplorerIsOpen() {
     const control = await new ActivityBar().getViewControl('Explorer');
     if (control === undefined) {