fix: provide stdio customization

closes #5

src/main/ts/spawn.ts

@@ -36,14 +36,16 @@ export type TChild = ReturnType<typeof cp.spawn>
 
 export type TInput = string | Buffer | Stream
 
+export type IO = 'pipe' | 'ignore' | 'inherit'
+
 export interface TSpawnCtxNormalized {
   id:         string,
   cwd:        string
   cmd:        string
   sync:       boolean
   args:       ReadonlyArray<string>
   input:      TInput | null
-  stdio:      ['pipe', 'pipe', 'pipe']
+  stdio:      [IO, IO, IO]
   detached:   boolean
   env:        Record<string, string | undefined>
   ee:         EventEmitter
@@ -182,12 +184,12 @@ export const invoke = (c: TSpawnCtxNormalized): TSpawnCtxNormalized => {
         })
         processInput(child, c.input || c.stdin)
 
-        child.stdout.pipe(c.stdout).on('data', d => {
+        child.stdout?.pipe(c.stdout).on('data', d => {
           stdout.push(d)
           stdall.push(d)
           c.ee.emit('stdout', d, c)
         })
-        child.stderr.pipe(c.stderr).on('data', d => {
+        child.stderr?.pipe(c.stderr).on('data', d => {
           stderr.push(d)
           stdall.push(d)
           c.ee.emit('stderr', d, c)

src/test/ts/x.test.ts

@@ -55,6 +55,10 @@ describe('$()', () => {
     assert.equal((await sorted).toString(), '1\n2\n3\n4\n5')
   })
 
+  it('handles custom stdio', async () => {
+    await $({stdio: ['inherit', 'inherit', 'inherit']})`ls`
+  })
+
   it('supports presets', () => {
     const $$ = $({sync: true, cmd: 'echo foo'})
     const $$$ = $$({cmd: 'echo bar'})