Allow specifying tsconfig path

README.md

@@ -47,7 +47,7 @@ The following options are unique to `rollup-plugin-typescript`:
 
 * `options.include` and `options.exclude` (each a minimatch pattern, or array of minimatch patterns), which determine which files are transpiled by Typescript (all `.ts` and `.tsx` files by default).
 
-* `tsconfig` when set to false, ignores any options specified in the config file
+* `tsconfig` when set to false, ignores any options specified in the config file. If set to a string that corresponds to a file path, the specified file will be used as config file.
 
 * `typescript` overrides TypeScript used for transpilation:
   ```js

src/index.js

@@ -27,8 +27,9 @@ export default function typescript ( options = {} ) {
 	delete options.tslib;
 
 	// Load options from `tsconfig.json` unless explicitly asked not to.
-	const tsconfig = options.tsconfig === false ? {} :
-		getCompilerOptionsFromTsConfig( typescript );
+	const tsconfig = options.tsconfig === false ?
+		{} :
+		getCompilerOptionsFromTsConfig( typescript, options.tsconfig );
 
 	delete options.tsconfig;
 

src/options.js

@@ -37,8 +37,11 @@ function findFile ( cwd, filename ) {
 	return null;
 }
 
-export function getCompilerOptionsFromTsConfig (typescript ) {
-	const existingTsConfig = findFile( process.cwd(), 'tsconfig.json' );
+export function getCompilerOptionsFromTsConfig (typescript, tsconfigPath) {
+	if (tsconfigPath && !existsSync(tsconfigPath)) {
+		throw new Error(`Could not find specified tsconfig.json at ${tsconfigPath}`);
+	}
+	const existingTsConfig = tsconfigPath || findFile( process.cwd(), 'tsconfig.json' );
 	if (!existingTsConfig) {
 		return {};
 	}

test/test.js

@@ -2,6 +2,7 @@ const assert = require( 'assert' );
 const rollup = require( 'rollup' );
 const assign = require( 'object-assign' );
 const typescript = require( '..' );
+const path = require('path');
 
 async function bundle (main, options) {
 	return rollup.rollup({
@@ -180,6 +181,27 @@ describe( 'rollup-plugin-typescript', () => {
 		assert.notEqual( usage, -1, 'should contain usage' );
 	});
 
+	it( 'allows specifying a path for tsconfig.json', async () => {
+		const code = await getCode( 'sample/tsconfig-jsx/main.tsx',
+			{tsconfig: path.resolve(__dirname, 'sample/tsconfig-jsx/tsconfig.json')});
+
+		const usage = code.indexOf( 'React.createElement("span", __assign({}, props), "Yo!")' );
+		assert.notEqual( usage, -1, 'should contain usage' );
+	});
+
+	it( 'throws if tsconfig cannot be found', async () => {
+		let caughtError = null;
+		try {
+			await bundle( 'sample/tsconfig-jsx/main.tsx', {tsconfig: path.resolve(__dirname, 'does-not-exist.json')} );
+		} catch (error) {
+			caughtError = error;
+		}
+
+		assert.ok(!!caughtError, 'Throws an error.');
+		assert.ok(caughtError.message.indexOf( 'Could not find specified tsconfig.json' ) !== -1,
+			`Unexpected error message: ${caughtError.message}`);
+	});
+
 	it('should throw on bad options', () => {
 		return bundle('does-not-matter.ts', {
 			foo: 'bar'