Use status bar to indicate whether selected Python interpreter is invalid

src/client/interpreter/display/index.ts

@@ -1,5 +1,13 @@
 import { inject, injectable } from 'inversify';
-import { Disposable, LanguageStatusItem, LanguageStatusSeverity, StatusBarAlignment, StatusBarItem, Uri } from 'vscode';
+import {
+    Disposable,
+    LanguageStatusItem,
+    LanguageStatusSeverity,
+    StatusBarAlignment,
+    StatusBarItem,
+    ThemeColor,
+    Uri,
+} from 'vscode';
 import { IExtensionSingleActivationService } from '../../activation/types';
 import { IApplicationShell, IWorkspaceService } from '../../common/application/types';
 import { Commands, PYTHON_LANGUAGE } from '../../common/constants';
@@ -133,6 +141,7 @@ export class InterpreterDisplay implements IInterpreterDisplay, IExtensionSingle
             } else {
                 this.statusBar.tooltip = '';
                 this.statusBar.color = '';
+                this.statusBar.backgroundColor = new ThemeColor('statusBarItem.warningBackground');
                 this.statusBar.text = `$(alert) ${InterpreterQuickPickList.browsePath.openButtonLabel}`;
                 this.currentlySelectedInterpreterDisplay = undefined;
             }
@@ -153,8 +162,10 @@ export class InterpreterDisplay implements IInterpreterDisplay, IExtensionSingle
                 text = text.startsWith('Python') ? text.substring('Python'.length).trim() : text;
                 this.languageStatus.text = text;
                 this.currentlySelectedInterpreterDisplay = interpreter.detailedDisplayName;
+                this.languageStatus.severity = LanguageStatusSeverity.Information;
             } else {
-                this.languageStatus.text = '$(alert) No Interpreter Selected';
+                this.languageStatus.severity = LanguageStatusSeverity.Warning;
+                this.languageStatus.text = `$(alert) ${InterpreterQuickPickList.browsePath.openButtonLabel}`;
                 this.languageStatus.detail = undefined;
                 this.currentlySelectedInterpreterDisplay = undefined;
             }

src/test/interpreters/display.unit.test.ts

@@ -31,6 +31,7 @@ import { InterpreterDisplay } from '../../client/interpreter/display';
 import { IServiceContainer } from '../../client/ioc/types';
 import * as logging from '../../client/logging';
 import { EnvironmentType, PythonEnvironment } from '../../client/pythonEnvironments/info';
+import { ThemeColor } from '../mocks/vsc';
 
 const info: PythonEnvironment = {
     architecture: Architecture.Unknown,
@@ -274,6 +275,11 @@ suite('Interpreters Display', () => {
                         TypeMoq.Times.once(),
                     );
                 } else {
+                    statusBar.verify(
+                        (s) =>
+                            (s.backgroundColor = TypeMoq.It.isValue(new ThemeColor('statusBarItem.warningBackground'))),
+                        TypeMoq.Times.once(),
+                    );
                     statusBar.verify((s) => (s.color = TypeMoq.It.isValue('')), TypeMoq.Times.once());
                     statusBar.verify(
                         (s) =>

src/test/mocks/vsc/index.ts

@@ -17,6 +17,10 @@ export function escapeCodicons(text: string): string {
     return text.replace(escapeCodiconsRegex, (match, escaped) => (escaped ? match : `\\${match}`));
 }
 
+export class ThemeColor {
+    constructor(public readonly id: string) {}
+}
+
 export enum ExtensionKind {
     /**
      * Extension runs where the UI runs.

src/test/vscode-mock.ts

@@ -62,6 +62,7 @@ export function initialize() {
     };
 }
 
+mockedVSCode.ThemeColor = vscodeMocks.ThemeColor;
 mockedVSCode.MarkdownString = vscodeMocks.MarkdownString;
 mockedVSCode.Hover = vscodeMocks.Hover;
 mockedVSCode.Disposable = vscodeMocks.Disposable as any;