Prefix attempt titles with that of parent test

Since titles must be unique throughout the test file, it's easier if
attempt titles are always prefixed with the already unique title of the
parent test.

lib/test.js

@@ -83,8 +83,10 @@ class ExecutionContext extends assert.Assertions {
 				let {title, isSet, isValid, isEmpty} = buildTitle(implementation);
 
 				if (!isSet || isEmpty) {
-					title = `${test.title} (attempt ${test.attemptCount + 1})`;
-				} else if (!isValid) {
+					title = `${test.title} ─ attempt ${test.attemptCount + 1}`;
+				} else if (isValid) {
+					title = `${test.title} ─ ${title}`;
+				} else {
 					throw new TypeError('`t.try()` titles must be strings'); // Throw synchronously!
 				}
 

test/test-try-commit.js

@@ -209,15 +209,15 @@ test('try-commit has proper titles, when going in depth and width', async t => {
 
 		await Promise.all([
 			a.try(async b => {
-				t.is(b.title, 'test (attempt 1)');
+				t.is(b.title, 'test ─ attempt 1');
 
 				await Promise.all([
-					b.try(c => t.is(c.title, 'test (attempt 1) (attempt 1)')),
-					b.try(c => t.is(c.title, 'test (attempt 1) (attempt 2)'))
+					b.try(c => t.is(c.title, 'test ─ attempt 1 ─ attempt 1')),
+					b.try(c => t.is(c.title, 'test ─ attempt 1 ─ attempt 2'))
 				]);
 			}),
-			a.try(b => t.is(b.title, 'test (attempt 2)')),
-			a.try(b => t.is(b.title, 'test (attempt 3)'))
+			a.try(b => t.is(b.title, 'test ─ attempt 2')),
+			a.try(b => t.is(b.title, 'test ─ attempt 3'))
 		]);
 	}).run();
 });
@@ -404,11 +404,11 @@ test('try-commit does not allow to use .end() in attempt when parent is regular
 
 test('try-commit accepts macros', async t => {
 	const macro = b => {
-		t.is(b.title, ' Title');
+		t.is(b.title, 'test ─ Title');
 		b.pass();
 	};
 
-	macro.title = providedTitle => `${providedTitle ? providedTitle : ''} Title`;
+	macro.title = (providedTitle = '') => `${providedTitle} Title`.trim();
 
 	const result = await ava(async a => {
 		const res = await a.try(macro);