auto select theme under development (fixes #62582)

src/vs/workbench/services/themes/electron-browser/colorThemeStore.ts

@@ -8,7 +8,7 @@ import * as nls from 'vs/nls';
 import * as types from 'vs/base/common/types';
 import * as resources from 'vs/base/common/resources';
 import { ExtensionsRegistry, ExtensionMessageCollector } from 'vs/workbench/services/extensions/common/extensionsRegistry';
-import { IColorTheme, ExtensionData, IThemeExtensionPoint, VS_LIGHT_THEME, VS_DARK_THEME, VS_HC_THEME } from 'vs/workbench/services/themes/common/workbenchThemeService';
+import { ExtensionData, IThemeExtensionPoint, VS_LIGHT_THEME, VS_DARK_THEME, VS_HC_THEME } from 'vs/workbench/services/themes/common/workbenchThemeService';
 import { ColorThemeData } from 'vs/workbench/services/themes/electron-browser/colorThemeData';
 import { IExtensionService } from 'vs/workbench/services/extensions/common/extensions';
 import { Event, Emitter } from 'vs/base/common/event';
@@ -155,7 +155,17 @@ export class ColorThemeStore {
 		});
 	}
 
-	public getColorThemes(): Promise<IColorTheme[]> {
+	public findThemeDataByParentLocation(parentLocation: URI): Promise<ColorThemeData[]> {
+		if (parentLocation) {
+			return this.getColorThemes().then(allThemes => {
+				return allThemes.filter(t => t.location && resources.isEqualOrParent(t.location, parentLocation));
+			});
+		}
+		return Promise.resolve([]);
+
+	}
+
+	public getColorThemes(): Promise<ColorThemeData[]> {
 		return this.extensionService.whenInstalledExtensionsRegistered().then(_ => {
 			return this.extensionsColorThemes;
 		});

src/vs/workbench/services/themes/electron-browser/fileIconThemeStore.ts

@@ -154,6 +154,15 @@ export class FileIconThemeStore {
 		});
 	}
 
+	public findThemeDataByParentLocation(parentLocation: URI): any {
+		if (parentLocation) {
+			return this.getFileIconThemes().then(allThemes => {
+				return allThemes.filter(t => t.location && resources.isEqualOrParent(t.location, parentLocation));
+			});
+		}
+		return Promise.resolve([]);
+	}
+
 	public getFileIconThemes(): Promise<FileIconThemeData[]> {
 		return this.extensionService.whenInstalledExtensionsRegistered().then(isReady => {
 			return this.knownIconThemes;

src/vs/workbench/services/themes/electron-browser/workbenchThemeService.ts

@@ -257,10 +257,22 @@ export class WorkbenchThemeService implements IWorkbenchThemeService {
 
 		return Promise.all([
 			this.colorThemeStore.findThemeDataBySettingsId(colorThemeSetting, DEFAULT_THEME_ID).then(theme => {
-				return this.setColorTheme(theme && theme.id, undefined);
+				return this.colorThemeStore.findThemeDataByParentLocation(this.environmentService.extensionDevelopmentLocationURI).then(devThemes => {
+					if (devThemes.length) {
+						return this.setColorTheme(devThemes[0].id, ConfigurationTarget.MEMORY);
+					} else {
+						return this.setColorTheme(theme && theme.id, undefined);
+					}
+				});
 			}),
 			this.iconThemeStore.findThemeBySettingsId(iconThemeSetting).then(theme => {
-				return this.setFileIconTheme(theme && theme.id, undefined);
+				return this.iconThemeStore.findThemeDataByParentLocation(this.environmentService.extensionDevelopmentLocationURI).then(devThemes => {
+					if (devThemes.length) {
+						return this.setFileIconTheme(devThemes[0].id, ConfigurationTarget.MEMORY);
+					} else {
+						return this.setFileIconTheme(theme && theme.id, undefined);
+					}
+				});
 			}),
 		]);
 	}