Add support for generics in expectError assertion - fixes #64

Author: SamVerschueren

source/lib/compiler.ts

@@ -21,6 +21,7 @@ const expectErrordiagnosticCodesToIgnore = new Set<DiagnosticCode>([
 	DiagnosticCode.PropertyDoesNotExistOnType,
 	DiagnosticCode.CannotAssignToReadOnlyProperty,
 	DiagnosticCode.TypeIsNotAssignableToOtherType,
+	DiagnosticCode.TypeDoesNotSatisfyTheConstraint,
 	DiagnosticCode.GenericTypeRequiresTypeArguments,
 	DiagnosticCode.ExpectedArgumentsButGotOther,
 	DiagnosticCode.NoOverloadMatches,

source/lib/interfaces.ts

@@ -23,12 +23,13 @@ export enum DiagnosticCode {
 	TopLevelAwaitOnlyAllowedWhenModuleESNextOrSystem = 1378,
 	GenericTypeRequiresTypeArguments = 2314,
 	TypeIsNotAssignableToOtherType = 2322,
+	TypeDoesNotSatisfyTheConstraint = 2344,
 	PropertyDoesNotExistOnType = 2339,
 	ArgumentTypeIsNotAssignableToParameterType = 2345,
 	CannotAssignToReadOnlyProperty = 2540,
 	ExpectedArgumentsButGotOther = 2554,
 	NoOverloadMatches = 2769,
-	PropertyMissingInType1ButRequiredInType2 = 2741
+	PropertyMissingInType1ButRequiredInType2 = 2741,
 }
 
 export interface Diagnostic {

source/test/fixtures/expect-error/functions/index.d.ts

@@ -1,6 +1,7 @@
 declare const one: {
 	(foo: string, bar: string): string;
 	(foo: number, bar: number): number;
+	<T extends string>(foo: T, bar: T): string;
 };
 
 export default one;

source/test/fixtures/expect-error/generics/index.d.ts

@@ -0,0 +1,5 @@
+declare const one: {
+	<T extends string>(foo: T, bar: T): T;
+};
+
+export default one;

source/test/fixtures/expect-error/generics/index.js

@@ -0,0 +1,3 @@
+module.exports.default = (foo, bar) => {
+	return foo + bar;
+};

source/test/fixtures/expect-error/generics/index.test-d.ts

@@ -0,0 +1,6 @@
+import {expectError} from '../../../..';
+import one from '.';
+
+expectError(one(true, true));
+
+expectError(one<number>(1, 2));

source/test/fixtures/expect-error/generics/package.json

@@ -0,0 +1,3 @@
+{
+	"name": "foo"
+}

source/test/test.ts

@@ -175,6 +175,12 @@ test('expectError for functions', async t => {
 	]);
 });
 
+test('expectError for generics', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/expect-error/generics')});
+
+	verify(t, diagnostics, []);
+});
+
 test('expectError should not ignore syntactical errors', async t => {
 	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/expect-error/syntax')});