Fixes #19291: electric character only works if the text before the closing bracket is whitespace only

src/vs/editor/common/modes/supports/electricCharacter.ts

@@ -94,6 +94,12 @@ export class BracketElectricCharacterSupport {
 			return null;
 		}
 
+		let textBeforeBracket = text.substring(0, r.startColumn - 1);
+		if (!/^\s*$/.test(textBeforeBracket)) {
+			// There is other text on the line before the bracket
+			return null;
+		}
+
 		return {
 			matchOpenBracket: bracketText
 		};

src/vs/editor/test/common/controller/cursor.test.ts

@@ -3269,7 +3269,7 @@ suite('ElectricCharacter', () => {
 		}, (model, cursor) => {
 			moveTo(cursor, 2, 2);
 			cursorCommand(cursor, H.Type, { text: '}' }, 'keyboard');
-			assert.deepEqual(model.getLineContent(2), '  a}');
+			assert.deepEqual(model.getLineContent(2), 'a}');
 		});
 		mode.dispose();
 	});
@@ -3311,6 +3311,23 @@ suite('ElectricCharacter', () => {
 		mode.dispose();
 	});
 
+	test('is no-op if the line has other content', () => {
+		let mode = new ElectricCharMode();
+		usingCursor({
+			text: [
+				'Math.max(',
+				'\t2',
+				'\t3'
+			],
+			languageIdentifier: mode.getLanguageIdentifier()
+		}, (model, cursor) => {
+			moveTo(cursor, 3, 3);
+			cursorCommand(cursor, H.Type, { text: ')' }, 'keyboard');
+			assert.deepEqual(model.getLineContent(3), '\t3)');
+		});
+		mode.dispose();
+	});
+
 	test('appends text', () => {
 		let mode = new ElectricCharMode();
 		usingCursor({