debt - make vscode.executeDocumentSymbolProvider very correct wrt what it returns (microsoft#251190)

Author: jrieken

src/vs/workbench/api/common/extHostApiCommands.ts

@@ -41,28 +41,21 @@ const newCommands: ApiCommand[] = [
 			if (isFalsyOrEmpty(value)) {
 				return undefined;
 			}
-			class MergedInfo extends types.SymbolInformation implements vscode.DocumentSymbol {
-				static to(symbol: languages.DocumentSymbol): MergedInfo {
-					const res = new MergedInfo(
-						symbol.name,
-						typeConverters.SymbolKind.to(symbol.kind),
-						symbol.containerName || '',
-						new types.Location(apiArgs[0], typeConverters.Range.to(symbol.range))
-					);
-					res.detail = symbol.detail;
-					res.range = res.location.range;
-					res.selectionRange = typeConverters.Range.to(symbol.selectionRange);
-					res.children = symbol.children ? symbol.children.map(MergedInfo.to) : [];
-					return res;
-				}
 
-				detail!: string;
-				range!: vscode.Range;
-				selectionRange!: vscode.Range;
-				children!: vscode.DocumentSymbol[];
-				override containerName: string = '';
+			function wrap(symbol: languages.DocumentSymbol): types.SymbolInformationAndDocumentSymbol {
+				return new types.SymbolInformationAndDocumentSymbol(
+					symbol.name,
+					typeConverters.SymbolKind.to(symbol.kind),
+					symbol.detail,
+					symbol.containerName || '',
+					apiArgs[0],
+					typeConverters.Range.to(symbol.range),
+					typeConverters.Range.to(symbol.selectionRange),
+					symbol.children ? symbol.children.map(wrap) : []
+				);
 			}
-			return value.map(MergedInfo.to);
+
+			return value.map(wrap);
 
 		})
 	),

src/vs/workbench/api/common/extHostTypes.ts

@@ -1383,19 +1383,8 @@ export class SymbolInformation {
 	}
 }
 
-@es5ClassCompat
-export class DocumentSymbol {
-
-	static validate(candidate: DocumentSymbol): void {
-		if (!candidate.name) {
-			throw new Error('name must not be falsy');
-		}
-		if (!candidate.range.contains(candidate.selectionRange)) {
-			throw new Error('selectionRange must be contained in fullRange');
-		}
-		candidate.children?.forEach(DocumentSymbol.validate);
-	}
 
+abstract class AbstractDocumentSymbol {
 	name: string;
 	detail: string;
 	kind: SymbolKind;
@@ -1411,11 +1400,56 @@ export class DocumentSymbol {
 		this.range = range;
 		this.selectionRange = selectionRange;
 		this.children = [];
+	}
+}
+
+@es5ClassCompat
+export class DocumentSymbol extends AbstractDocumentSymbol {
+
+	static validate(candidate: DocumentSymbol): void {
+		if (!candidate.name) {
+			throw new Error('name must not be falsy');
+		}
+		if (!candidate.range.contains(candidate.selectionRange)) {
+			throw new Error('selectionRange must be contained in fullRange');
+		}
+		candidate.children?.forEach(DocumentSymbol.validate);
+	}
 
+	constructor(name: string, detail: string, kind: SymbolKind, range: Range, selectionRange: Range) {
+		super(name, detail, kind, range, selectionRange);
 		DocumentSymbol.validate(this);
 	}
+
+	static override[Symbol.hasInstance](candidate: unknown): boolean {
+		if (!isObject(candidate)) {
+			throw new TypeError();
+		}
+		return candidate instanceof AbstractDocumentSymbol
+			|| candidate instanceof SymbolInformationAndDocumentSymbol;
+	}
 }
 
+// This is a special type that's used from the `vscode.executeDocumentSymbolProvider` API
+// command which implements both shapes, vscode.SymbolInformation _and_ vscode.DocumentSymbol
+export class SymbolInformationAndDocumentSymbol extends SymbolInformation implements vscode.DocumentSymbol {
+
+	detail: string;
+	range: vscode.Range;
+	selectionRange: vscode.Range;
+	children: vscode.DocumentSymbol[];
+	override containerName: string;
+
+	constructor(name: string, kind: vscode.SymbolKind, detail: string, containerName: string, uri: URI, range: Range, selectionRange: Range, children?: SymbolInformationAndDocumentSymbol[]) {
+		super(name, kind, containerName, new Location(uri, range));
+
+		this.containerName = containerName;
+		this.detail = detail;
+		this.range = range;
+		this.selectionRange = selectionRange;
+		this.children = children ?? [];
+	}
+}
 
 export enum CodeActionTriggerKind {
 	Invoke = 1,

src/vs/workbench/api/test/browser/extHostApiCommands.test.ts

@@ -774,8 +774,9 @@ suite('ExtHostLanguageFeatureCommands', function () {
 				assert.strictEqual(values.length, 2);
 				const [first, second] = values;
 				assert.strictEqual(first instanceof types.SymbolInformation, true);
-				assert.strictEqual(first instanceof types.DocumentSymbol, false);
+				assert.strictEqual(first instanceof types.DocumentSymbol, true);
 				assert.strictEqual(second instanceof types.SymbolInformation, true);
+				assert.strictEqual(second instanceof types.DocumentSymbol, true);
 				assert.strictEqual(first.name, 'DocumentSymbol');
 				assert.strictEqual(first.children.length, 1);
 				assert.strictEqual(second.name, 'SymbolInformation');