Infer value for moduleResolution tsconfig if not set (#149)

readme.md

@@ -135,8 +135,9 @@ By default, `tsd` applies the following configuration:
 	"target": "es2017",
 	"lib": ["es2017"],
 	"module": "commonjs",
-	// The following option is set and is not overridable:
-	"moduleResolution": "node"
+	// The following option is set and is not overridable.
+	// It is set to `nodenext` if `module` is `nodenext`, `node16` if `module` is `node16` or `node` otherwise.
+	"moduleResolution": "node" | "node16" | "nodenext"
 }
 ```
 
@@ -153,7 +154,7 @@ These options will be overridden if a `tsconfig.json` file is found in your proj
 }
 ```
 
-*Default options will apply if you don't override them explicitly.* You can't override the `moduleResolution` option.
+*Default options will apply if you don't override them explicitly.* You can't override the `moduleResolution` option. 
 
 ## Assertions
 

source/lib/config.ts

@@ -27,19 +27,29 @@ export default (pkg: PackageJsonWithTsdConfig, cwd: string): Config => {
 		cwd
 	);
 
+	const combinedCompilerOptions = {
+		...tsConfigCompilerOptions,
+		...packageJsonCompilerOptions,
+	};
+
+	const module = combinedCompilerOptions.module ?? ModuleKind.CommonJS;
+
 	return {
 		directory: 'test-d',
 		...pkgConfig,
 		compilerOptions: {
 			strict: true,
 			jsx: JsxEmit.React,
 			lib: parseRawLibs(['es2017', 'dom', 'dom.iterable'], cwd),
-			module: ModuleKind.CommonJS,
+			module,
 			target: ScriptTarget.ES2017,
 			esModuleInterop: true,
-			...tsConfigCompilerOptions,
-			...packageJsonCompilerOptions,
-			moduleResolution: ModuleResolutionKind.NodeJs,
+			...combinedCompilerOptions,
+			moduleResolution: module === ModuleKind.NodeNext ?
+				ModuleResolutionKind.NodeNext :
+				module === ModuleKind.Node16 ?
+					ModuleResolutionKind.Node16 :
+					ModuleResolutionKind.NodeJs,
 			skipLibCheck: false
 		}
 	};

source/test/fixtures/module-resolution/node16-from-package-json/index.d.ts

@@ -0,0 +1,3 @@
+declare const foo: string;
+
+export default foo;

source/test/fixtures/module-resolution/node16-from-package-json/index.js

@@ -0,0 +1 @@
+module.exports.default = 'foo';

source/test/fixtures/module-resolution/node16-from-package-json/index.test-d.ts

@@ -0,0 +1,4 @@
+import foo from 'foo';
+import {expectType} from '../../../../index.js';
+
+expectType<string>(foo);

source/test/fixtures/module-resolution/node16-from-package-json/package.json

@@ -0,0 +1,10 @@
+{
+	"name": "foo",
+	"type": "module",
+	"exports": "./index.js",
+	"tsd": {
+		"compilerOptions": {
+			"module": "node16"
+		}
+	}
+}

source/test/fixtures/module-resolution/node16-from-tsconfig-json/index.d.ts

@@ -0,0 +1,3 @@
+declare const foo: string;
+
+export default foo;

source/test/fixtures/module-resolution/node16-from-tsconfig-json/index.js

@@ -0,0 +1 @@
+module.exports.default = 'foo';

source/test/fixtures/module-resolution/node16-from-tsconfig-json/index.test-d.ts

@@ -0,0 +1,4 @@
+import foo from 'foo';
+import {expectType} from '../../../../index.js';
+
+expectType<string>(foo);

source/test/fixtures/module-resolution/node16-from-tsconfig-json/package.json

@@ -0,0 +1,5 @@
+{
+	"name": "foo",
+	"type": "module",
+	"exports": "./index.js"
+}

source/test/fixtures/module-resolution/node16-from-tsconfig-json/tsconfig.json

@@ -0,0 +1,5 @@
+{
+	"compilerOptions": {
+		"module": "node16"
+	}
+}

source/test/fixtures/module-resolution/nodenext-from-package-json/index.d.ts

@@ -0,0 +1,3 @@
+declare const foo: string;
+
+export default foo;

source/test/fixtures/module-resolution/nodenext-from-package-json/index.js

@@ -0,0 +1 @@
+module.exports.default = 'foo';

source/test/fixtures/module-resolution/nodenext-from-package-json/index.test-d.ts

@@ -0,0 +1,4 @@
+import foo from 'foo';
+import {expectType} from '../../../../index.js';
+
+expectType<string>(foo);

source/test/fixtures/module-resolution/nodenext-from-package-json/package.json

@@ -0,0 +1,10 @@
+{
+	"name": "foo",
+	"type": "module",
+	"exports": "./index.js",
+	"tsd": {
+		"compilerOptions": {
+			"module": "nodenext"
+		}
+	}
+}

source/test/fixtures/module-resolution/nodenext-from-tsconfig-json/index.d.ts

@@ -0,0 +1,3 @@
+declare const foo: string;
+
+export default foo;

source/test/fixtures/module-resolution/nodenext-from-tsconfig-json/index.js

@@ -0,0 +1 @@
+module.exports.default = 'foo';

source/test/fixtures/module-resolution/nodenext-from-tsconfig-json/index.test-d.ts

@@ -0,0 +1,4 @@
+import foo from 'foo';
+import {expectType} from '../../../../index.js';
+
+expectType<string>(foo);

source/test/fixtures/module-resolution/nodenext-from-tsconfig-json/package.json

@@ -0,0 +1,5 @@
+{
+	"name": "foo",
+	"type": "module",
+	"exports": "./index.js"
+}

source/test/fixtures/module-resolution/nodenext-from-tsconfig-json/tsconfig.json

@@ -0,0 +1,5 @@
+{
+	"compilerOptions": {
+		"module": "nodenext"
+	}
+}

source/test/test.ts

@@ -138,6 +138,30 @@ test('allow specifying a lib in tsconfig.json', async t => {
 	verify(t, diagnostics, []);
 });
 
+test('use moduleResolution `nodenext` when module is `nodenext` in tsconfig.json', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/module-resolution/nodenext-from-tsconfig-json')});
+
+	verify(t, diagnostics, []);
+});
+
+test('use moduleResolution `nodenext` when module is `nodenext` in package.json', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/module-resolution/nodenext-from-package-json')});
+
+	verify(t, diagnostics, []);
+});
+
+test('use moduleResolution `node16` when module is `node16` in tsconfig.json', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/module-resolution/node16-from-tsconfig-json')});
+
+	verify(t, diagnostics, []);
+});
+
+test('use moduleResolution `node16` when module is `node16` in package.json', async t => {
+	const diagnostics = await tsd({cwd: path.join(__dirname, 'fixtures/module-resolution/node16-from-package-json')});
+
+	verify(t, diagnostics, []);
+});
+
 test('add support for esm with esModuleInterop', async t => {
 	const diagnostics = await tsd({
 		cwd: path.join(__dirname, 'fixtures/esm')