From 906f124ada3a7379e7d476dd6557df4c4695da3b Mon Sep 17 00:00:00 2001
From: await-ovo <41503212+await-ovo@users.noreply.github.com>
Date: Thu, 3 Nov 2022 17:30:22 +0800
Subject: [PATCH] feat: respect target config in tsconfig.json (#757)

Co-authored-by: EGOIST <0x142857@gmail.com>
---
 src/index.ts       |  8 +++++++-
 test/index.test.ts | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 8ed9c026..a1b9840c 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -53,7 +53,6 @@ const normalizeOptions = async (
     ...optionsOverride,
   }
   const options: Partial<NormalizedOptions> = {
-    target: 'node14',
     outDir: 'dist',
     ..._options,
     format:
@@ -113,10 +112,17 @@ const normalizeOptions = async (
         ...(options.dts.compilerOptions || {}),
       }
     }
+    if (!options.target) {
+      options.target = tsconfig.data?.compilerOptions?.target?.toLowerCase()
+    }
   } else if (options.tsconfig) {
     throw new PrettyError(`Cannot find tsconfig: ${options.tsconfig}`)
   }
 
+  if (!options.target) {
+    options.target = 'node14'
+  }
+  
   return options as NormalizedOptions
 }
 
diff --git a/test/index.test.ts b/test/index.test.ts
index 663d789e..f15bc24f 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -1102,3 +1102,44 @@ test('treeshake should work with hashbang', async () => {
     "
   `)
 })
+
+test('support target in tsconfig.json', async () => {
+  const { getFileContent } = await run(
+    getTestName(),
+    {
+      'input.ts': `await import('./foo')`,
+      'foo.ts': `export default 'foo'`,
+      'tsconfig.json': `{
+        "compilerOptions": {
+          "baseUrl":".",
+          "target": "esnext"
+        }
+      }`
+    }, 
+    {
+      flags: ['--format', 'esm', ],
+    }
+  )
+  expect(await getFileContent('dist/input.mjs')).contains('await import(')
+})
+
+test('override target in tsconfig.json', async () => {
+  await expect(
+    run(
+      getTestName(),
+      {
+        'input.ts': `await import('./foo')`,
+        'foo.ts': `export default 'foo'`,
+        'tsconfig.json': `{
+          "compilerOptions": {
+            "baseUrl":".",
+            "target": "esnext"
+          }
+        }`
+      }, 
+      {
+        flags: ['--format', 'esm', '--target', 'es2018' ],
+      }
+    )
+  ).rejects.toThrowError(`Top-level await is not available in the configured target environment ("es2018")`)
+})
\ No newline at end of file