add a test for #2564

Author: evanw

scripts/js-api-tests.js

@@ -4139,6 +4139,19 @@ let transformTests = {
     assert.strictEqual((await esbuild.transform(input, { loader: 'ts', tsconfigRaw: { compilerOptions: { alwaysStrict: true, strict: false } } })).code, `"use strict";\nconsole.log(123);\n`)
   },
 
+  async tsconfigRawTarget({ esbuild }) {
+    // The "target" from "tsconfig.json" should apply, but esbuild's "target" should override
+
+    assert.strictEqual((await esbuild.transform('x => x', { loader: 'ts', tsconfigRaw: { compilerOptions: { target: 'ES6' } } })).code, `(x) => x;\n`)
+    assert.strictEqual((await esbuild.transform('x => x', { loader: 'ts', tsconfigRaw: { compilerOptions: { target: 'ES5' } } })).code, `(function(x) {\n  return x;\n});\n`)
+
+    assert.strictEqual((await esbuild.transform('x => x', { loader: 'ts', target: 'es6' })).code, `(x) => x;\n`)
+    assert.strictEqual((await esbuild.transform('x => x', { loader: 'ts', target: 'es5' })).code, `(function(x) {\n  return x;\n});\n`)
+
+    assert.strictEqual((await esbuild.transform('x => x', { loader: 'ts', target: 'es5', tsconfigRaw: { compilerOptions: { target: 'ES6' } } })).code, `(function(x) {\n  return x;\n});\n`)
+    assert.strictEqual((await esbuild.transform('x => x', { loader: 'ts', target: 'es6', tsconfigRaw: { compilerOptions: { target: 'ES5' } } })).code, `(x) => x;\n`)
+  },
+
   async tsImplicitUseDefineForClassFields({ esbuild }) {
     var { code } = await esbuild.transform(`class Foo { foo }`, {
       loader: 'ts',