Add options argument, close #9

src/index.d.ts

@@ -1,2 +1,8 @@
-declare const browserslistToEsbuild: (browserslistConfig?: readonly string[] | string) => string[]
+import browserslist from 'browserslist'
+
+declare function browserslistToEsbuild(
+  browserslistConfig?: string | readonly string[],
+  options?: browserslist.Options
+): string[]
+
 export default browserslistToEsbuild

src/index.js

@@ -2,13 +2,13 @@ import browserslist from 'browserslist'
 
 // convert the browserslist field in package.json to
 // esbuild compatible array of browsers
-export default function browserslistToEsbuild(browserslistConfig) {
+export default function browserslistToEsbuild(browserslistConfig, options = {}) {
   if (!browserslistConfig) {
     // the path from where the script is run
     const path = process.cwd()
 
     // read config if none is passed
-    browserslistConfig = browserslist.loadConfig({ path })
+    browserslistConfig = browserslist.loadConfig({ path, ...options })
   }
 
   const SUPPORTED_ESBUILD_TARGETS = [
@@ -34,7 +34,7 @@ export default function browserslistToEsbuild(browserslistConfig) {
   const separator = ' '
 
   return (
-    browserslist(browserslistConfig)
+    browserslist(browserslistConfig, options)
       // filter out the unsupported ones
       .filter((b) => !UNSUPPORTED.some((u) => b.startsWith(u)))
       // replaces safari TP with latest safari version

test/fixtures/browserslistrc/.browserslistrc

@@ -0,0 +1,10 @@
+[production]
+> 1%
+not dead
+
+[modern]
+last 1 chrome version
+last 1 firefox version
+
+[ssr]
+node 12

test/test.js

@@ -27,10 +27,11 @@ test('works by passing browsers as string', (t) => {
 })
 
 test('works by loading package.json config', (t) => {
-  const packageJsonDir = path.resolve(__dirname, './fixtures')
+  const packageJsonDir = path.resolve(__dirname, './fixtures/packageJson')
 
   // makes process.cwd() use that folder
-  const cwdStub = sinon.stub(process, 'cwd').returns(packageJsonDir)
+  if (!t.context.cwd) t.context.cwd = sinon.stub(process, 'cwd')
+  const cwdStub = t.context.cwd.returns(packageJsonDir)
 
   process.env.NODE_ENV = 'production'
   t.deepEqual(browserslistToEsbuild(), [
@@ -45,6 +46,41 @@ test('works by loading package.json config', (t) => {
   process.env.NODE_ENV = 'development'
   t.deepEqual(browserslistToEsbuild(), ['chrome120', 'firefox121', 'safari17.2'])
 
+  cwdStub.restore()
+  process.env.NODE_ENV = ''
+})
+
+test('works by loading .browserslist config', (t) => {
+  const browserslistrcDir = path.resolve(__dirname, './fixtures/browserslistrc')
+
+  // makes process.cwd() use that folder
+  if (!t.context.cwd) t.context.cwd = sinon.stub(process, 'cwd')
+  const cwdStub = t.context.cwd.returns(browserslistrcDir)
+
+  t.deepEqual(browserslistToEsbuild(), [
+    'chrome109',
+    'edge119',
+    'firefox119',
+    'ios16.6',
+    'safari16.6',
+  ])
+
+  process.env.BROWSERSLIST_ENV = 'ssr'
+  t.deepEqual(browserslistToEsbuild(), ['node12.22'])
+
+  cwdStub.restore()
+  process.env.BROWSERSLIST_ENV = ''
+})
+
+test('the options argument works', (t) => {
+  const browserslistrcDir = path.resolve(__dirname, './fixtures/browserslistrc')
+
+  // makes process.cwd() use that folder
+  if (!t.context.cwd) t.context.cwd = sinon.stub(process, 'cwd')
+  const cwdStub = t.context.cwd.returns(browserslistrcDir)
+
+  t.deepEqual(browserslistToEsbuild(undefined, { env: 'ssr' }), ['node12.22'])
+
   cwdStub.restore()
 })