refactor!: don't resolve tsconfig (#370)

BREAKING CHANGE:
- `target` now defaults to `es2020`
- Required esbuild version should be 0.18 and above
- For tsconfig, switch to use the built-in strategy of esbuild. (For example, esbuild v0.18 and later will no longer follow `target` in `tsconfig.json`). Read more in [esbuild changelog](https://github.com/evanw/esbuild/releases/tag/v0.18.0)

example/class.ts

@@ -0,0 +1,7 @@
+export class A {
+  foo = 'bar'
+  num
+  constructor() {
+    this.num ||= 2
+  }
+}

example/index.js

@@ -3,5 +3,6 @@ import * as Vue from 'vue'
 import React from 'react'
 import * as Three from 'three'
 import * as _ from 'lodash'
+import * as clz from './class'
 
-export { Foo, Vue, React, Three, _ }
+export { Foo, Vue, React, Three, _, clz }

example/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "useDefineForClassFields": false
+  }
+}

package.json

@@ -37,11 +37,10 @@
     "@rollup/pluginutils": "^5.0.4",
     "debug": "^4.3.4",
     "es-module-lexer": "^1.3.1",
-    "joycon": "^3.1.1",
-    "jsonc-parser": "^3.2.0"
+    "joycon": "^3.1.1"
   },
   "peerDependencies": {
-    "esbuild": ">=0.10.1",
+    "esbuild": ">=0.18.0",
     "rollup": "^1.20.0 || ^2.0.0 || ^3.0.0"
   },
   "engines": {

src/index.ts

@@ -1,18 +1,19 @@
 import { existsSync, statSync } from 'fs'
 import { extname, resolve, dirname, join } from 'path'
 import { Plugin as RollupPlugin } from 'rollup'
+import { readFile } from 'fs/promises'
 import { transform, Loader, TransformOptions } from 'esbuild'
 import { MarkOptional } from 'ts-essentials'
 import { createFilter, FilterPattern } from '@rollup/pluginutils'
 import createDebug from 'debug'
-import { getOptions } from './options'
 import { minify, getRenderChunk } from './minify'
 import { warn } from './warn'
 import {
   optimizeDeps as doOptimizeDeps,
   OptimizeDepsOptions,
   OptimizeDepsResult,
 } from './optimizer/optmize-deps'
+import { getTsconfig } from './tsconfig'
 
 export { minify }
 
@@ -25,10 +26,7 @@ const defaultLoaders: { [ext: string]: Loader } = {
   '.tsx': 'tsx',
 }
 
-export type Options = Omit<
-  TransformOptions,
-  'sourcemap' | 'loader' | 'tsconfigRaw'
-> & {
+export type Options = Omit<TransformOptions, 'sourcemap' | 'loader'> & {
   include?: FilterPattern
   exclude?: FilterPattern
   sourceMap?: boolean
@@ -152,19 +150,17 @@ export default ({
         return null
       }
 
-      const defaultOptions =
-        tsconfig === false ? {} : await getOptions(dirname(id), tsconfig)
+      const tsconfigRaw =
+        tsconfig === false
+          ? undefined
+          : await getTsconfig(dirname(id), tsconfig)
 
       const result = await transform(code, {
         loader,
-        target: defaultOptions.target || 'es2017',
-        jsxFactory: defaultOptions.jsxFactory,
-        jsxFragment: defaultOptions.jsxFragment,
-        jsx: defaultOptions.jsx,
-        // Compat: passing this option in older esbuild version will result in error
-        ...(defaultOptions.jsxDev ? { jsxDev: true } : {}),
         sourcemap: sourceMap,
         sourcefile: id,
+        tsconfigRaw,
+        target: 'es2020',
         ...esbuildOptions,
       })
 

src/tsconfig.ts

@@ -0,0 +1,18 @@
+import { readFile } from 'fs/promises'
+import JoyCon from 'joycon'
+
+const joycon = new JoyCon()
+
+joycon.addLoader({
+  test: /\.json$/,
+  load: (file) => readFile(file, 'utf8'),
+})
+
+export const getTsconfig = async (
+  cwd: string,
+  tsconfig?: string,
+): Promise<string> => {
+  // This call is cached
+  const { data } = await joycon.load([tsconfig || 'tsconfig.json'], cwd)
+  return data
+}