Ignore errors from libs in node_modules folders

source/lib/assertions/index.ts

@@ -13,7 +13,7 @@ export enum Assertion {
 }
 
 // List of diagnostic handlers attached to the assertion
-const assertionHandlers = new Map<string, Handler | Handler[]>([
+const assertionHandlers = new Map<Assertion, Handler>([
 	[Assertion.EXPECT_TYPE, isIdentical],
 	[Assertion.EXPECT_NOT_TYPE, isNotIdentical],
 	[Assertion.EXPECT_NOT_ASSIGNABLE, isNotAssignable],
@@ -39,12 +39,7 @@ export const handle = (typeChecker: TypeChecker, assertions: Map<Assertion, Set<
 			continue;
 		}
 
-		const handlers = Array.isArray(handler) ? handler : [handler];
-
-		// Iterate over the handlers and invoke them
-		for (const fn of handlers) {
-			diagnostics.push(...fn(typeChecker, nodes));
-		}
+		diagnostics.push(...handler(typeChecker, nodes));
 	}
 
 	return diagnostics;

source/lib/compiler.ts

@@ -99,7 +99,10 @@ export const getDiagnostics = (context: Context): Diagnostic[] => {
 	const expectedErrorsLocationsWithFoundDiagnostics: Location[] = [];
 
 	for (const diagnostic of tsDiagnostics) {
-		if (!diagnostic.file) {
+		/* Filter out all diagnostic messages without a file or from node_modules directories, files under
+		 * node_modules are most definitely not under test.
+		 */
+		if (!diagnostic.file || /[/\\]node_modules[/\\]/.test(diagnostic.file.fileName)) {
 			continue;
 		}
 

source/test/fixtures/exclude-node-modules/index.d.ts

@@ -0,0 +1,4 @@
+export default function (foo: number): number | null;
+
+export type Foo = Bar;
+

source/test/fixtures/exclude-node-modules/index.js

@@ -0,0 +1,3 @@
+module.exports.default = foo => {
+	return foo > 0 ? foo : null;
+};

source/test/fixtures/exclude-node-modules/index.test-d.ts

@@ -0,0 +1,4 @@
+import {expectType} from '../../..';
+import aboveZero from '.';
+
+expectType<number | null>(aboveZero(1));

source/test/fixtures/exclude-node-modules/package.json

@@ -0,0 +1,8 @@
+{
+	"name": "foo",
+	"tsd": {
+		"compilerOptions": {
+			"noLib": true
+		}
+	}
+}

source/test/test.ts

@@ -2,6 +2,7 @@ import * as path from 'path';
 import test from 'ava';
 import {verify} from './fixtures/utils';
 import tsd from '..';
+import {Diagnostic} from '../lib/interfaces';
 
 test('throw if no type definition was found', async t => {
 	await t.throwsAsync(tsd({cwd: path.join(__dirname, 'fixtures/no-tsd')}), {message: 'The type definition `index.d.ts` does not exist. Create one and try again.'});
@@ -313,3 +314,47 @@ test('includes extended config files along with found ones', async t => {
 		[6, 64, 'error', 'Not all code paths return a value.'],
 	]);
 });
+
+test('errors in libs from node_modules are not reported', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/exclude-node-modules')});
+
+	const [nodeModuleDiagnostics, testFileDiagnostics, otherDiagnostics] = diagnostics.reduce(
+		([nodeModuleDiags, testFileDiags, otherDiags], diagnostic) => {
+			if (/[/\\]node_modules[/\\]/.test(diagnostic.fileName)) {
+				nodeModuleDiags.push(diagnostic);
+			} else if (/[/\\]fixtures[/\\]exclude-node-modules[/\\]/.test(diagnostic.fileName)) {
+				testFileDiags.push(diagnostic);
+			} else {
+				otherDiags.push(diagnostic);
+			}
+			return [nodeModuleDiags, testFileDiags, otherDiags];
+		},
+		[[], [], []] as Diagnostic[][]
+	);
+
+	t.deepEqual(
+		nodeModuleDiagnostics.length,
+		0,
+		'There must be no errors from node_modules folders when standard lib is not available (option `"noLib": true`).',
+	);
+
+	t.true(
+		otherDiagnostics.length > 0,
+		'There must be errors from tsd lib when standard lib is not available (option `"noLib": true`).',
+	);
+
+	const alloweOtherFileFailures = [
+		/[/\\]lib[/\\]index.d.ts$/,
+		/[/\\]lib[/\\]interfaces.d.ts$/,
+	];
+	otherDiagnostics.forEach(diagnostic => {
+		t.true(
+			alloweOtherFileFailures.some(allowedFileRe => allowedFileRe.test(diagnostic.fileName)),
+			`Found diagnostic from an unexpected file: ${diagnostic.fileName} - ${diagnostic.message}`,
+		);
+	});
+
+	verify(t, testFileDiagnostics, [
+		[3, 18, 'error', 'Cannot find name \'Bar\'.']
+	]);
+});