Implement site-packages watcher service with automatic package refresh

Co-authored-by: eleanorjboyd <26030610+eleanorjboyd@users.noreply.github.com>

Author: Copilot

src/extension.ts

@@ -63,6 +63,7 @@ import { ProjectView } from './features/views/projectView';
 import { PythonStatusBarImpl } from './features/views/pythonStatusBar';
 import { updateViewsAndStatus } from './features/views/revealHandler';
 import { ProjectItem } from './features/views/treeViewItems';
+import { SitePackagesWatcherService } from './features/packageWatcher';
 import { EnvironmentManagers, ProjectCreators, PythonProjectManager } from './internal.api';
 import { registerSystemPythonFeatures } from './managers/builtin/main';
 import { SysPythonManager } from './managers/builtin/sysPythonManager';
@@ -191,6 +192,10 @@ export async function activate(context: ExtensionContext): Promise<PythonEnviron
     createManagerReady(envManagers, projectManager, context.subscriptions);
     context.subscriptions.push(envManagers);
 
+    // Initialize automatic package refresh service
+    const sitePackagesWatcher = new SitePackagesWatcherService(envManagers);
+    context.subscriptions.push(sitePackagesWatcher);
+
     const terminalActivation = new TerminalActivationImpl();
     const shellEnvsProviders = createShellEnvProviders();
     const shellStartupProviders = createShellStartupProviders();

src/features/packageWatcher/index.ts

@@ -0,0 +1,2 @@
+export { SitePackagesWatcherService } from './sitePackagesWatcherService';
+export { resolveSitePackagesPath, isSitePackagesDirectory } from './sitePackagesUtils';

src/features/packageWatcher/sitePackagesUtils.ts

@@ -0,0 +1,100 @@
+import * as path from 'path';
+import * as fs from 'fs-extra';
+import { Uri } from 'vscode';
+import { PythonEnvironment } from '../../api';
+import { traceVerbose, traceWarn } from '../../common/logging';
+
+/**
+ * Resolves the site-packages directory path for a given Python environment.
+ * This function handles different platforms and Python versions.
+ * 
+ * @param environment The Python environment to resolve site-packages for
+ * @returns Promise<Uri | undefined> The Uri to the site-packages directory, or undefined if not found
+ */
+export async function resolveSitePackagesPath(environment: PythonEnvironment): Promise<Uri | undefined> {
+    const sysPrefix = environment.sysPrefix;
+    if (!sysPrefix) {
+        traceWarn(`No sysPrefix available for environment: ${environment.displayName}`);
+        return undefined;
+    }
+
+    traceVerbose(`Resolving site-packages for environment: ${environment.displayName}, sysPrefix: ${sysPrefix}`);
+
+    // Common site-packages locations to check
+    const candidates = getSitePackagesCandidates(sysPrefix);
+    
+    // Check each candidate path
+    for (const candidate of candidates) {
+        try {
+            if (await fs.pathExists(candidate)) {
+                const uri = Uri.file(candidate);
+                traceVerbose(`Found site-packages at: ${candidate}`);
+                return uri;
+            }
+        } catch (error) {
+            traceVerbose(`Error checking site-packages candidate ${candidate}: ${error}`);
+        }
+    }
+
+    traceWarn(`Could not find site-packages directory for environment: ${environment.displayName}`);
+    return undefined;
+}
+
+/**
+ * Gets candidate site-packages paths for different platforms and Python versions.
+ * 
+ * @param sysPrefix The sys.prefix of the Python environment
+ * @returns Array of candidate paths to check
+ */
+function getSitePackagesCandidates(sysPrefix: string): string[] {
+    const candidates: string[] = [];
+    
+    // Windows: typically in Lib/site-packages
+    if (process.platform === 'win32') {
+        candidates.push(path.join(sysPrefix, 'Lib', 'site-packages'));
+    }
+    
+    // Unix-like systems: typically in lib/python*/site-packages
+    // We'll check common Python version patterns
+    const pythonVersions = [
+        'python3.12', 'python3.11', 'python3.10', 'python3.9', 'python3.8', 'python3.7',
+        'python3', // fallback
+    ];
+    
+    for (const pyVer of pythonVersions) {
+        candidates.push(path.join(sysPrefix, 'lib', pyVer, 'site-packages'));
+    }
+    
+    // Additional locations for conda environments
+    candidates.push(path.join(sysPrefix, 'site-packages')); // Some minimal environments
+    
+    return candidates;
+}
+
+/**
+ * Checks if a path is likely a site-packages directory by looking for common markers.
+ * 
+ * @param sitePkgPath Path to check
+ * @returns Promise<boolean> True if the path appears to be a site-packages directory
+ */
+export async function isSitePackagesDirectory(sitePkgPath: string): Promise<boolean> {
+    try {
+        const stat = await fs.stat(sitePkgPath);
+        if (!stat.isDirectory()) {
+            return false;
+        }
+
+        // Check for common site-packages markers
+        const contents = await fs.readdir(sitePkgPath);
+        
+        // Look for common packages or pip-related files
+        const markers = [
+            'pip', 'setuptools', 'wheel', // Common packages
+            '__pycache__', // Python cache directory
+        ];
+        
+        return markers.some(marker => contents.includes(marker)) || contents.length > 0;
+    } catch {
+        return false;
+    }
+}

src/features/packageWatcher/sitePackagesWatcherService.ts

@@ -0,0 +1,197 @@
+import { Disposable, FileSystemWatcher } from 'vscode';
+import { PythonEnvironment } from '../../api';
+import { traceError, traceInfo, traceVerbose } from '../../common/logging';
+import { createFileSystemWatcher } from '../../common/workspace.apis';
+import { EnvironmentManagers, InternalDidChangeEnvironmentsEventArgs, InternalPackageManager } from '../../internal.api';
+import { resolveSitePackagesPath } from './sitePackagesUtils';
+
+/**
+ * Manages file system watchers for site-packages directories across all Python environments.
+ * Automatically refreshes package lists when packages are installed or uninstalled.
+ */
+export class SitePackagesWatcherService implements Disposable {
+    private readonly watchers = new Map<string, FileSystemWatcher>();
+    private readonly disposables: Disposable[] = [];
+
+    constructor(private readonly environmentManagers: EnvironmentManagers) {
+        this.initializeService();
+    }
+
+    /**
+     * Initializes the service by setting up event listeners and creating watchers for existing environments.
+     */
+    private initializeService(): void {
+        traceInfo('SitePackagesWatcherService: Initializing automatic package refresh service');
+
+        // Listen for environment changes
+        this.disposables.push(
+            this.environmentManagers.onDidChangeEnvironments(this.handleEnvironmentChanges.bind(this))
+        );
+
+        // Set up watchers for existing environments
+        this.setupWatchersForExistingEnvironments();
+    }
+
+    /**
+     * Sets up watchers for all existing environments.
+     */
+    private async setupWatchersForExistingEnvironments(): Promise<void> {
+        try {
+            const managers = this.environmentManagers.managers;
+            for (const manager of managers) {
+                try {
+                    const environments = await manager.getEnvironments('all');
+                    for (const environment of environments) {
+                        await this.addWatcherForEnvironment(environment);
+                    }
+                } catch (error) {
+                    traceError(`Failed to get environments from manager ${manager.id}:`, error);
+                }
+            }
+        } catch (error) {
+            traceError('Failed to setup watchers for existing environments:', error);
+        }
+    }
+
+    /**
+     * Handles environment changes by adding or removing watchers as needed.
+     */
+    private async handleEnvironmentChanges(event: InternalDidChangeEnvironmentsEventArgs): Promise<void> {
+        for (const change of event.changes) {
+            try {
+                switch (change.kind) {
+                    case 'add':
+                        await this.addWatcherForEnvironment(change.environment);
+                        break;
+                    case 'remove':
+                        this.removeWatcherForEnvironment(change.environment);
+                        break;
+                }
+            } catch (error) {
+                traceError(`Error handling environment change for ${change.environment.displayName}:`, error);
+            }
+        }
+    }
+
+    /**
+     * Adds a file system watcher for the given environment's site-packages directory.
+     */
+    private async addWatcherForEnvironment(environment: PythonEnvironment): Promise<void> {
+        const envId = environment.envId.id;
+        
+        // Check if we already have a watcher for this environment
+        if (this.watchers.has(envId)) {
+            traceVerbose(`Watcher already exists for environment: ${environment.displayName}`);
+            return;
+        }
+
+        try {
+            const sitePackagesUri = await resolveSitePackagesPath(environment);
+            if (!sitePackagesUri) {
+                traceVerbose(`Could not resolve site-packages path for environment: ${environment.displayName}`);
+                return;
+            }
+
+            const pattern = `${sitePackagesUri.fsPath}/**`;
+            const watcher = createFileSystemWatcher(
+                pattern,
+                false, // don't ignore create events
+                false, // don't ignore change events  
+                false  // don't ignore delete events
+            );
+
+            // Set up event handlers
+            watcher.onDidCreate(() => this.onSitePackagesChange(environment));
+            watcher.onDidChange(() => this.onSitePackagesChange(environment));
+            watcher.onDidDelete(() => this.onSitePackagesChange(environment));
+
+            this.watchers.set(envId, watcher);
+            traceInfo(`Created site-packages watcher for environment: ${environment.displayName} at ${sitePackagesUri.fsPath}`);
+
+        } catch (error) {
+            traceError(`Failed to create watcher for environment ${environment.displayName}:`, error);
+        }
+    }
+
+    /**
+     * Removes the file system watcher for the given environment.
+     */
+    private removeWatcherForEnvironment(environment: PythonEnvironment): void {
+        const envId = environment.envId.id;
+        const watcher = this.watchers.get(envId);
+        
+        if (watcher) {
+            watcher.dispose();
+            this.watchers.delete(envId);
+            traceInfo(`Removed site-packages watcher for environment: ${environment.displayName}`);
+        }
+    }
+
+    /**
+     * Handles site-packages changes by triggering a package refresh.
+     */
+    private async onSitePackagesChange(environment: PythonEnvironment): Promise<void> {
+        try {
+            traceVerbose(`Site-packages changed for environment: ${environment.displayName}, triggering package refresh`);
+            
+            // Get the package manager for this environment
+            const packageManager = this.getPackageManagerForEnvironment(environment);
+            if (packageManager) {
+                // Trigger refresh asynchronously to avoid blocking file system events
+                setImmediate(async () => {
+                    try {
+                        await packageManager.refresh(environment);
+                        traceInfo(`Package list refreshed automatically for environment: ${environment.displayName}`);
+                    } catch (error) {
+                        traceError(`Failed to refresh packages for environment ${environment.displayName}:`, error);
+                    }
+                });
+            } else {
+                traceVerbose(`No package manager found for environment: ${environment.displayName}`);
+            }
+        } catch (error) {
+            traceError(`Error handling site-packages change for environment ${environment.displayName}:`, error);
+        }
+    }
+
+    /**
+     * Gets the appropriate package manager for the given environment.
+     */
+    private getPackageManagerForEnvironment(environment: PythonEnvironment): InternalPackageManager | undefined {
+        try {
+            // Try to get package manager by environment manager's preferred package manager
+            const envManager = this.environmentManagers.managers.find(m => 
+                m.id === environment.envId.managerId
+            );
+            
+            if (envManager) {
+                return this.environmentManagers.getPackageManager(envManager.preferredPackageManagerId);
+            }
+
+            // Fallback to default package manager
+            return this.environmentManagers.getPackageManager(environment);
+        } catch (error) {
+            traceError(`Error getting package manager for environment ${environment.displayName}:`, error);
+            return undefined;
+        }
+    }
+
+    /**
+     * Disposes all watchers and cleans up resources.
+     */
+    dispose(): void {
+        traceInfo('SitePackagesWatcherService: Disposing automatic package refresh service');
+        
+        // Dispose all watchers
+        for (const watcher of this.watchers.values()) {
+            watcher.dispose();
+        }
+        this.watchers.clear();
+
+        // Dispose event listeners
+        for (const disposable of this.disposables) {
+            disposable.dispose();
+        }
+        this.disposables.length = 0;
+    }
+}