Allow omitting types property for non-barrel main

source/lib/index.ts

@@ -14,7 +14,12 @@ export interface Options {
 }
 
 const findTypingsFile = async (pkg: any, options: Options) => {
-	const typings = options.typingsFile || pkg.types || pkg.typings || 'index.d.ts';
+	const typings =
+		options.typingsFile ||
+		pkg.types ||
+		pkg.typings ||
+		(pkg.main && path.parse(pkg.main).name + '.d.ts') ||
+		'index.d.ts';
 	const typingsExist = await pathExists(path.join(options.cwd, typings));
 
 	if (!typingsExist) {

source/test/fixtures/no-explicit-types-property/with-main-barrel/index.test-d.ts

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

source/test/fixtures/no-explicit-types-property/with-main-barrel/package.json

@@ -0,0 +1,7 @@
+{
+	"name": "foo",
+	"main": "index.js",
+	"files": [
+		"index.d.ts"
+	]
+}

source/test/fixtures/no-explicit-types-property/with-main-other/foo.d.ts

@@ -0,0 +1,6 @@
+declare const one: {
+	(foo: string, bar: string): string;
+	(foo: number, bar: number): number;
+};
+
+export default one;

source/test/fixtures/no-explicit-types-property/with-main-other/foo.js

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

source/test/fixtures/test-non-barrel-main-via-types/foo.test-d.ts → source/test/fixtures/no-explicit-types-property/with-main-other/foo.test-d.ts

@@ -1,5 +1,6 @@
-import {expectType} from '../../..';
+import {expectType, expectError} from '../../../..';
 import one from './foo';
 
 expectType<string>(one('foo', 'bar'));
 expectType<number>(one(1, 2));
+expectError(one(1, 2));

source/test/fixtures/test-non-barrel-main-via-types/package.json → source/test/fixtures/no-explicit-types-property/with-main-other/package.json

@@ -1,9 +1,7 @@
 {
 	"name": "foo",
 	"main": "foo.js",
-	"types": "foo.d.ts",
 	"files": [
-		"foo.js",
 		"foo.d.ts"
 	]
 }

source/test/fixtures/no-explicit-types-property/without-main/index.d.ts

@@ -0,0 +1,6 @@
+declare const one: {
+	(foo: string, bar: string): string;
+	(foo: number, bar: number): number;
+};
+
+export default one;

source/test/fixtures/no-explicit-types-property/without-main/index.js

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

source/test/fixtures/no-explicit-types-property/without-main/index.test-d.ts

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

source/test/fixtures/no-explicit-types-property/without-main/package.json

@@ -0,0 +1,6 @@
+{
+	"name": "foo",
+	"files": [
+		"index.d.ts"
+	]
+}

source/test/test.ts

@@ -145,10 +145,28 @@ test('support non-barrel main', async t => {
 	verify(t, diagnostics, []);
 });
 
-test('support non-barrel main using `types` property', async t => {
-	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/test-non-barrel-main-via-types')});
+test('allow omitting `types` property when `main` property is missing but main is a barrel (`index.js`) and .d.ts file matches main', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/no-explicit-types-property/without-main')});
 
-	verify(t, diagnostics, []);
+	verify(t, diagnostics, [
+		[6, 0, 'error', 'Expected an error, but found none.']
+	]);
+});
+
+test('allow omitting `types` property when `main` property is set to a barrel (`index.js`) and .d.ts file matches main', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/no-explicit-types-property/with-main-barrel')});
+
+	verify(t, diagnostics, [
+		[6, 0, 'error', 'Expected an error, but found none.']
+	]);
+});
+
+test('allow omitting `types` property when `main` property is set to non-barrel (`foo.js`) and .d.ts file matches main', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/no-explicit-types-property/with-main-other')});
+
+	verify(t, diagnostics, [
+		[6, 0, 'error', 'Expected an error, but found none.']
+	]);
 });
 
 test('support testing in sub-directories', async t => {