Fix unexpected blocking for pwsh command activation

package.json

@@ -12,7 +12,8 @@
         "Other"
     ],
     "enabledApiProposals": [
-        "terminalShellEnv"
+        "terminalShellEnv",
+        "terminalDataWriteEvent"
     ],
     "capabilities": {
         "untrustedWorkspaces": {

src/common/utils/asyncUtils.ts

@@ -1,3 +1,9 @@
 export async function sleep(milliseconds: number) {
     return new Promise<void>((resolve) => setTimeout(resolve, milliseconds));
 }
+
+export function timeout(ms: number): Promise<void> {
+    return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+// TODO: Advanced timeout from core async: https://github.com/microsoft/vscode-python-environments/issues/953

src/common/window.apis.ts

@@ -49,6 +49,14 @@ export function onDidChangeTerminalShellIntegration(
     return window.onDidChangeTerminalShellIntegration(listener, thisArgs, disposables);
 }
 
+export function onDidWriteTerminalData(
+    listener: (e: { readonly terminal: Terminal; readonly data: string }) => any,
+    thisArgs?: any,
+    disposables?: Disposable[],
+): Disposable {
+    return window.onDidWriteTerminalData(listener, thisArgs, disposables);
+}
+
 export function showOpenDialog(options?: OpenDialogOptions): Thenable<Uri[] | undefined> {
     return window.showOpenDialog(options);
 }

src/features/terminal/utils.ts

@@ -1,19 +1,115 @@
 import * as path from 'path';
-import { Terminal, TerminalOptions, Uri } from 'vscode';
+import { Disposable, Terminal, TerminalOptions, Uri } from 'vscode';
 import { PythonEnvironment, PythonProject, PythonProjectEnvironmentApi, PythonProjectGetterApi } from '../../api';
-import { sleep } from '../../common/utils/asyncUtils';
+import { timeout } from '../../common/utils/asyncUtils';
+import { createSimpleDebounce } from '../../common/utils/debounce';
+import { onDidChangeTerminalShellIntegration, onDidWriteTerminalData } from '../../common/window.apis';
 import { getConfiguration, getWorkspaceFolders } from '../../common/workspace.apis';
 
 export const SHELL_INTEGRATION_TIMEOUT = 500; // 0.5 seconds
 export const SHELL_INTEGRATION_POLL_INTERVAL = 20; // 0.02 seconds
 
+/**
+ * Three conditions in a Promise.race:
+ * 1. Timeout based on VS Code's terminal.integrated.shellIntegration.timeout setting
+ * 2. Shell integration becoming available (window.onDidChangeTerminalShellIntegration event)
+ * 3. Detection of common prompt patterns in terminal output
+ */
 export async function waitForShellIntegration(terminal: Terminal): Promise<boolean> {
-    let timeout = 0;
-    while (!terminal.shellIntegration && timeout < SHELL_INTEGRATION_TIMEOUT) {
-        await sleep(SHELL_INTEGRATION_POLL_INTERVAL);
-        timeout += SHELL_INTEGRATION_POLL_INTERVAL;
+    if (terminal.shellIntegration) {
+        return true;
+    }
+
+    const config = getConfiguration('terminal.integrated');
+    const timeoutValue = config.get<number | undefined>('shellIntegration.timeout');
+    const timeoutMs = timeoutValue === undefined || -1 ? 5000 : timeoutValue;
+
+    const disposables: Disposable[] = [];
+
+    try {
+        const result = await Promise.race([
+            // Condition 1: Shell integration timeout setting
+            timeout(timeoutMs).then(() => false),
+
+            // Condition 2: Shell integration becomes available
+            new Promise<boolean>((resolve) => {
+                disposables.push(
+                    onDidChangeTerminalShellIntegration((e) => {
+                        if (e.terminal === terminal) {
+                            resolve(true);
+                        }
+                    }),
+                );
+            }),
+
+            // Condition 3: Detect prompt patterns in terminal output
+            new Promise<boolean>((resolve) => {
+                let dataSoFar = '';
+                const debounced = createSimpleDebounce(50, () => {
+                    if (dataSoFar && detectsCommonPromptPattern(dataSoFar)) {
+                        resolve(false);
+                    }
+                });
+                disposables.push(
+                    onDidWriteTerminalData((e) => {
+                        if (e.terminal === terminal) {
+                            dataSoFar += e.data;
+                            debounced.trigger();
+                        }
+                    }),
+                );
+            }),
+        ]);
+
+        return result;
+    } finally {
+        disposables.forEach((d) => d.dispose());
     }
-    return terminal.shellIntegration !== undefined;
+}
+
+// Detects if the given text content appears to end with a common prompt pattern.
+function detectsCommonPromptPattern(terminalData: string): boolean {
+    if (terminalData.trim().length === 0) {
+        return false;
+    }
+
+    const sanitizedTerminalData = removeAnsiEscapeCodes(terminalData);
+    // PowerShell prompt: PS C:\> or similar patterns
+    if (/PS\s+[A-Z]:\\.*>\s*$/.test(sanitizedTerminalData)) {
+        return true;
+    }
+
+    // Command Prompt: C:\path>
+    if (/^[A-Z]:\\.*>\s*$/.test(sanitizedTerminalData)) {
+        return true;
+    }
+
+    // Bash-style prompts ending with $
+    if (/\$\s*$/.test(sanitizedTerminalData)) {
+        return true;
+    }
+
+    // Root prompts ending with #
+    if (/#\s*$/.test(sanitizedTerminalData)) {
+        return true;
+    }
+
+    // Python REPL prompt
+    if (/^>>>\s*$/.test(sanitizedTerminalData)) {
+        return true;
+    }
+
+    // Custom prompts ending with the starship character (\u276f)
+    if (/\u276f\s*$/.test(sanitizedTerminalData)) {
+        return true;
+    }
+
+    // Generic prompts ending with common prompt characters
+    if (/[>%]\s*$/.test(sanitizedTerminalData)) {
+        return true;
+    }
+
+    return false;
 }
 
 export function isTaskTerminal(terminal: Terminal): boolean {
@@ -171,3 +267,28 @@ export async function getAllDistinctProjectEnvironments(
 
     return envs.length > 0 ? envs : undefined;
 }
+
+// Defacto standard: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
+const CSI_SEQUENCE = /(?:\x1b\[|\x9b)[=?>!]?[\d;:]*["$#'* ]?[a-zA-Z@^`{}|~]/;
+const OSC_SEQUENCE = /(?:\x1b\]|\x9d).*?(?:\x1b\\|\x07|\x9c)/;
+const ESC_SEQUENCE = /\x1b(?:[ #%\(\)\*\+\-\.\/]?[a-zA-Z0-9\|}~@])/;
+const CONTROL_SEQUENCES = new RegExp(
+    '(?:' + [CSI_SEQUENCE.source, OSC_SEQUENCE.source, ESC_SEQUENCE.source].join('|') + ')',
+    'g',
+);
+
+/**
+ * Strips ANSI escape sequences from a string.
+ * @param str The dastringa stringo strip the ANSI escape sequences from.
+ *
+ * @example
+ * removeAnsiEscapeCodes('\u001b[31mHello, World!\u001b[0m');
+ * // 'Hello, World!'
+ */
+export function removeAnsiEscapeCodes(str: string): string {
+    if (str) {
+        str = str.replace(CONTROL_SEQUENCES, '');
+    }
+
+    return str;
+}

src/vscode.proposed.terminalDataWriteEvent.d.ts

@@ -0,0 +1,31 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+declare module 'vscode' {
+    // https://github.com/microsoft/vscode/issues/78502
+    //
+    // This API is still proposed but we don't intent on promoting it to stable due to problems
+    // around performance. See #145234 for a more likely API to get stabilized.
+
+    export interface TerminalDataWriteEvent {
+        /**
+         * The {@link Terminal} for which the data was written.
+         */
+        readonly terminal: Terminal;
+        /**
+         * The data being written.
+         */
+        readonly data: string;
+    }
+
+    namespace window {
+        /**
+         * An event which fires when the terminal's child pseudo-device is written to (the shell).
+         * In other words, this provides access to the raw data stream from the process running
+         * within the terminal, including VT sequences.
+         */
+        export const onDidWriteTerminalData: Event<TerminalDataWriteEvent>;
+    }
+}