Adding "base" to files.exclude breaks VS Code (fixes #36081)

src/vs/base/common/glob.ts

@@ -450,7 +450,7 @@ export function parse(arg1: string | IExpression | IRelativePattern, options: IG
 	}
 
 	// Glob with String
-	if (typeof arg1 === 'string' || (arg1 as IRelativePattern).base) {
+	if (typeof arg1 === 'string' || isRelativePattern(arg1)) {
 		const parsedPattern = parsePattern(arg1 as string | IRelativePattern, options);
 		if (parsedPattern === NULL) {
 			return FALSE;
@@ -471,6 +471,12 @@ export function parse(arg1: string | IExpression | IRelativePattern, options: IG
 	return parsedExpression(<IExpression>arg1, options);
 }
 
+function isRelativePattern(obj: any): obj is IRelativePattern {
+	const rp = obj as IRelativePattern;
+
+	return typeof rp.base === 'string' && typeof rp.pattern === 'string';
+}
+
 /**
  * Same as `parse`, but the ParsedExpression is guaranteed to return a Promise
  */

src/vs/base/test/node/glob.test.ts

@@ -933,4 +933,8 @@ suite('Glob', () => {
 			assert(!glob.match(p, '/DNXConsoleApp/foo/Program.cs'));
 		}
 	});
+
+	test('pattern with "base" does not explode - #36081', function () {
+		assert.ok(glob.match({ 'base': true }, 'base'));
+	});
 });
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