Add "Don't Show Again" to env file notification (#1393)

The env file injection notification fires on every `.env` file save with
no way to suppress it, including for non-Python users who happen to use
`.env` files.

### Changes

- **`terminalEnvVarInjector.ts`**: Extract notification into
`showEnvFileNotification()`, gate on global persistent state, offer
"Don't Show Again" button that persists the dismissal via
`getGlobalPersistentState()`
- **`localize.ts`**: Add `Common.dontShowAgain` for reuse across
features
- Switch from direct `window.showInformationMessage` to the
`showInformationMessage` wrapper (consistent with project convention,
enables stubbing in tests)
- 5 new unit tests covering show/suppress/persist paths

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Author: Copilot

src/common/localize.ts

@@ -15,6 +15,7 @@ export namespace Common {
     export const ok = l10n.t('Ok');
     export const quickCreate = l10n.t('Quick Create');
     export const installPython = l10n.t('Install Python');
+    export const dontShowAgain = l10n.t("Don't Show Again");
     export const dontAskAgain = l10n.t("Don't ask again");
 }
 
@@ -223,6 +224,9 @@ export namespace ActivationStrings {
         Commands.viewLogs,
     );
     export const activatingEnvironment = l10n.t('Activating environment');
+    export const envFileInjectionDisabled = l10n.t(
+        'An environment file is configured but terminal environment injection is disabled. Enable "python.terminal.useEnvFile" to use environment variables from .env files in terminals.',
+    );
 }
 
 export namespace UvInstallStrings {

src/features/terminal/terminalEnvVarInjector.ts

@@ -7,15 +7,19 @@ import {
     Disposable,
     EnvironmentVariableScope,
     GlobalEnvironmentVariableCollection,
-    window,
     workspace,
     WorkspaceFolder,
 } from 'vscode';
-import { traceError, traceVerbose } from '../../common/logging';
+import { ActivationStrings, Common } from '../../common/localize';
+import { traceError, traceLog, traceVerbose } from '../../common/logging';
+import { getGlobalPersistentState } from '../../common/persistentState';
 import { resolveVariables } from '../../common/utils/internalVariables';
+import { showInformationMessage } from '../../common/window.apis';
 import { getConfiguration, getWorkspaceFolder } from '../../common/workspace.apis';
 import { EnvVarManager } from '../execution/envVariableManager';
 
+export const ENV_FILE_NOTIFICATION_DONT_SHOW_KEY = 'python-envs:terminal:ENV_FILE_NOTIFICATION_DONT_SHOW';
+
 /**
  * Manages injection of workspace-specific environment variables into VS Code terminals
  * using the GlobalEnvironmentVariableCollection API.
@@ -65,9 +69,9 @@ export class TerminalEnvVarInjector implements Disposable {
 
                 // Only show notification when env vars change and we have an env file but injection is disabled
                 if (!useEnvFile && envFilePath) {
-                    window.showInformationMessage(
-                        'An environment file is configured but terminal environment injection is disabled. Enable "python.terminal.useEnvFile" to use environment variables from .env files in terminals.',
-                    );
+                    this.showEnvFileNotification().catch((error) => {
+                        traceError('Failed to show env file notification:', error);
+                    });
                 }
 
                 if (args.changeType === 2) {
@@ -208,6 +212,23 @@ export class TerminalEnvVarInjector implements Disposable {
         }
     }
 
+    /**
+     * Show a notification about env file injection being disabled, with a "Don't Show Again" option.
+     */
+    private async showEnvFileNotification(): Promise<void> {
+        const state = await getGlobalPersistentState();
+        const dontShow = await state.get<boolean>(ENV_FILE_NOTIFICATION_DONT_SHOW_KEY);
+        if (dontShow) {
+            return;
+        }
+
+        const result = await showInformationMessage(ActivationStrings.envFileInjectionDisabled, Common.dontShowAgain);
+        if (result === Common.dontShowAgain) {
+            await state.set(ENV_FILE_NOTIFICATION_DONT_SHOW_KEY, true);
+            traceLog(`User selected "Don't Show Again" for env file notification`);
+        }
+    }
+
     /**
      * Dispose of the injector and clean up resources.
      */

src/test/features/terminalEnvVarInjector.unit.test.ts

@@ -13,9 +13,15 @@ import {
     WorkspaceFolder,
     workspace,
 } from 'vscode';
+import { Common } from '../../common/localize';
+import * as persistentState from '../../common/persistentState';
+import * as windowApis from '../../common/window.apis';
 import * as workspaceApis from '../../common/workspace.apis';
 import { EnvVarManager } from '../../features/execution/envVariableManager';
-import { TerminalEnvVarInjector } from '../../features/terminal/terminalEnvVarInjector';
+import {
+    ENV_FILE_NOTIFICATION_DONT_SHOW_KEY,
+    TerminalEnvVarInjector,
+} from '../../features/terminal/terminalEnvVarInjector';
 
 interface MockScopedCollection {
     clear: sinon.SinonStub;
@@ -307,4 +313,125 @@ suite('TerminalEnvVarInjector', () => {
             }
         });
     });
+
+    suite('env file notification with Don\'t Show Again', () => {
+        let envChangeCallback: ((args: { uri?: Uri; changeType: number }) => void) | undefined;
+        let mockState: { get: sinon.SinonStub; set: sinon.SinonStub; clear: sinon.SinonStub };
+        let showInfoMessageStub: sinon.SinonStub;
+
+        setup(() => {
+            mockState = {
+                get: sinon.stub(),
+                set: sinon.stub().resolves(),
+                clear: sinon.stub().resolves(),
+            };
+            sinon.stub(persistentState, 'getGlobalPersistentState').resolves(mockState);
+            showInfoMessageStub = sinon.stub(windowApis, 'showInformationMessage');
+
+            // Capture the onDidChangeEnvironmentVariables listener
+            envVarManager.reset();
+            envVarManager
+                .setup((m) => m.onDidChangeEnvironmentVariables)
+                .returns(() => {
+                    return (listener: (args: { uri?: Uri; changeType: number }) => void): Disposable => {
+                        envChangeCallback = listener;
+                        return new Disposable(() => {});
+                    };
+                });
+            envVarManager
+                .setup((m) => m.getEnvironmentVariables(typeMoq.It.isAny()))
+                .returns(() => Promise.resolve({}));
+
+            sinon.stub(workspaceApis, 'getWorkspaceFolder').returns(testWorkspaceFolder);
+        });
+
+        test('should show notification with Don\'t Show Again button when env file configured but injection disabled', async () => {
+            getConfigurationStub.returns(
+                createMockConfig({ useEnvFile: false, envFilePath: '${workspaceFolder}/.env' }) as WorkspaceConfiguration,
+            );
+            mockState.get.resolves(false);
+            showInfoMessageStub.resolves(undefined);
+
+            injector = new TerminalEnvVarInjector(envVarCollection.object, envVarManager.object);
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(envChangeCallback, 'Event handler should be registered');
+            envChangeCallback!({ uri: Uri.file(testWorkspacePath), changeType: 1 });
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(showInfoMessageStub.calledOnce, 'Should show notification');
+            assert.ok(
+                showInfoMessageStub.calledWith(sinon.match.string, Common.dontShowAgain),
+                'Should include Don\'t Show Again button',
+            );
+        });
+
+        test('should not show notification when Don\'t Show Again was previously selected', async () => {
+            getConfigurationStub.returns(
+                createMockConfig({ useEnvFile: false, envFilePath: '${workspaceFolder}/.env' }) as WorkspaceConfiguration,
+            );
+            mockState.get.resolves(true);
+
+            injector = new TerminalEnvVarInjector(envVarCollection.object, envVarManager.object);
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(envChangeCallback, 'Event handler should be registered');
+            envChangeCallback!({ uri: Uri.file(testWorkspacePath), changeType: 1 });
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(showInfoMessageStub.notCalled, 'Should not show notification when dismissed');
+        });
+
+        test('should persist preference when Don\'t Show Again is clicked', async () => {
+            getConfigurationStub.returns(
+                createMockConfig({ useEnvFile: false, envFilePath: '${workspaceFolder}/.env' }) as WorkspaceConfiguration,
+            );
+            mockState.get.resolves(false);
+            showInfoMessageStub.resolves(Common.dontShowAgain);
+
+            injector = new TerminalEnvVarInjector(envVarCollection.object, envVarManager.object);
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(envChangeCallback, 'Event handler should be registered');
+            envChangeCallback!({ uri: Uri.file(testWorkspacePath), changeType: 1 });
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(
+                mockState.set.calledWith(ENV_FILE_NOTIFICATION_DONT_SHOW_KEY, true),
+                'Should persist Don\'t Show Again preference',
+            );
+        });
+
+        test('should not show notification when useEnvFile is true', async () => {
+            getConfigurationStub.returns(
+                createMockConfig({ useEnvFile: true, envFilePath: '${workspaceFolder}/.env' }) as WorkspaceConfiguration,
+            );
+            mockState.get.resolves(false);
+
+            injector = new TerminalEnvVarInjector(envVarCollection.object, envVarManager.object);
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(envChangeCallback, 'Event handler should be registered');
+            envChangeCallback!({ uri: Uri.file(testWorkspacePath), changeType: 1 });
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(showInfoMessageStub.notCalled, 'Should not show notification when useEnvFile is true');
+        });
+
+        test('should not show notification when no envFile is configured', async () => {
+            getConfigurationStub.returns(
+                createMockConfig({ useEnvFile: false }) as WorkspaceConfiguration,
+            );
+            mockState.get.resolves(false);
+
+            injector = new TerminalEnvVarInjector(envVarCollection.object, envVarManager.object);
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(envChangeCallback, 'Event handler should be registered');
+            envChangeCallback!({ uri: Uri.file(testWorkspacePath), changeType: 1 });
+            await new Promise((resolve) => setTimeout(resolve, 50));
+
+            assert.ok(showInfoMessageStub.notCalled, 'Should not show notification when no envFile configured');
+        });
+    });
 });