Make sure commit()/discard() only called once

Author: qlonik

lib/test.js

@@ -65,7 +65,11 @@ function tryTest(fn) {
 
 	const commitFn = (ret, toCommit) => {
 		if (commitCalled) {
-			this.saveFirstError(new Error('Either commit() or discard() was already called'));
+			if (discarded) {
+				this.saveFirstError(new Error('The discard() was already called'));
+			} else {
+				this.saveFirstError(new Error('The commit() was already called'));
+			}
 			return;
 		}
 		commitCalled = true;
@@ -101,11 +105,22 @@ function tryTest(fn) {
 		finished = true;
 		return Object.assign({}, ret, {
 			commit: () => commitFn(ret, true),
-			discard: () => commitFn(ret, false)
+			discard: () => {
+				discarded = true;
+				return commitFn(ret, false);
+			}
 		});
 	});
 
 	finishedRunning.discard = () => {
+		if (finished) {
+			this.saveFirstError(new Error('Attempt is already resolved'));
+			return;
+		}
+		if (discarded) {
+			this.saveFirstError(new Error('The discard() was already called'));
+			return;
+		}
 		discarded = true;
 		this.decrementAttemptAssertion();
 	};

test/test.js

@@ -983,7 +983,54 @@ test('try-commit fails when calling commit twice', t => {
 	}).run().then(result => {
 		t.false(result.passed);
 		t.ok(result.error);
-		t.match(result.error.message, /was already called/);
+		t.match(result.error.message, /The commit\(\) was already called/);
+		t.is(result.error.name, 'Error');
+	});
+});
+
+test('try-commit fails when calling discard twice', t => {
+	return ava(a => {
+		return a.try(b => b.pass()).then(res => {
+			res.discard();
+			res.discard();
+		});
+	}).run().then(result => {
+		t.false(result.passed);
+		t.ok(result.error);
+		t.match(result.error.message, /The discard\(\) was already called/);
+		t.is(result.error.name, 'Error');
+	});
+});
+
+test('try-commit fails when calling discard on promise twice', t => {
+	return ava(a => {
+		const pr = a.try(b => b.pass());
+		pr.discard();
+		pr.discard();
+
+		return pr.then(res => {
+			t.is(res, null);
+		});
+	}).run().then(result => {
+		t.false(result.passed);
+		t.ok(result.error);
+		t.match(result.error.message, /The discard\(\) was already called/);
+		t.is(result.error.name, 'Error');
+	});
+});
+
+test('try-commit fails when calling discard on promise after attempt resolved', t => {
+	return ava(a => {
+		const attemptPromise = a.try(b => b.pass());
+		return attemptPromise.then(res => {
+			t.true(res.passed);
+			res.commit();
+			attemptPromise.discard();
+		});
+	}).run().then(result => {
+		t.false(result.passed);
+		t.ok(result.error);
+		t.match(result.error.message, /Attempt is already resolved/);
 		t.is(result.error.name, 'Error');
 	});
 });