allow to ask if a document content provider already exists, prep for #65400

src/vs/editor/common/services/resolverService.ts

@@ -24,6 +24,11 @@ export interface ITextModelService {
 	 * Registers a specific `scheme` content provider.
 	 */
 	registerTextModelContentProvider(scheme: string, provider: ITextModelContentProvider): IDisposable;
+
+	/**
+	 * Check if a provider for the given `scheme` exists
+	 */
+	hasTextModelContentProvider(scheme: string): boolean;
 }
 
 export interface ITextModelContentProvider {

src/vs/editor/standalone/browser/simpleServices.ts

@@ -116,6 +116,10 @@ export class SimpleEditorModelResolverService implements ITextModelService {
 		};
 	}
 
+	public hasTextModelContentProvider(scheme: string): boolean {
+		return false;
+	}
+
 	private findModel(editor: ICodeEditor, resource: URI): ITextModel | null {
 		let model = editor.getModel();
 		if (model && model.uri.toString() !== resource.toString()) {

src/vs/workbench/services/textmodelResolver/common/textModelResolverService.ts

@@ -96,6 +96,10 @@ class ResourceModelCollection extends ReferenceCollection<Promise<ITextEditorMod
 		});
 	}
 
+	hasTextModelContentProvider(scheme: string): boolean {
+		return this.providers[scheme] !== undefined;
+	}
+
 	private resolveTextModelContent(key: string): Promise<ITextModel> {
 		const resource = URI.parse(key);
 		const providers = this.providers[resource.scheme] || [];
@@ -162,4 +166,8 @@ export class TextModelResolverService implements ITextModelService {
 	registerTextModelContentProvider(scheme: string, provider: ITextModelContentProvider): IDisposable {
 		return this.resourceModelCollection.registerTextModelContentProvider(scheme, provider);
 	}
+
+	hasTextModelContentProvider(scheme: string): boolean {
+		return this.resourceModelCollection.hasTextModelContentProvider(scheme);
+	}
 }