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Use inherited stdin instead of piped #192

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merged 1 commit into from
Aug 16, 2021
Merged

Use inherited stdin instead of piped #192

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99 changes: 55 additions & 44 deletions index.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -32,9 +32,10 @@ export const globby = Object.assign(function globby(...args) {
}, globbyModule)

export function $(pieces, ...args) {
let {verbose, cwd, shell, prefix} = $
let __from = (new Error().stack.split(/^\s*at\s/m)[2]).trim()

let cmd = pieces[0], i = 0
let verbose = $.verbose
while (i < args.length) {
let s
if (Array.isArray(args[i])) {
Expand All @@ -44,19 +45,26 @@ export function $(pieces, ...args) {
}
cmd += s + pieces[++i]
}
if (verbose) {
printCmd(cmd)
}
let options = {
cwd: $.cwd,
shell: typeof $.shell === 'string' ? $.shell : true,
windowsHide: true,
}
let child = spawn($.prefix + cmd, options)
let promise = new ProcessPromise((resolve, reject) => {

let resolve, reject
let promise = new ProcessPromise((...args) => [resolve, reject] = args)

promise._run = () => {
if (promise.child) return
if (promise._prerun) promise._prerun()
if (verbose) {
printCmd(cmd)
}

let child = spawn(prefix + cmd, {
cwd,
shell: typeof shell === 'string' ? shell : true,
stdio: [promise._inheritStdin ? 'inherit' : 'pipe', 'pipe', 'pipe'],
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Why use 'inherit' instead of 'pipe' for this parameter.

in cases like this, errors are reported：

#!/usr/bin/env zx
const sleep = () => new Promise((resolve) => setTimeout(resolve, 1000));

let p = $`read var; echo "$var";`

await sleep();

p.stdin.write('Hello, stdin!\n')  //  p.stdin is null

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stdin of the child process is not necessarily a synchronous call, so is there a flaw in the design?

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@antonmedv antonmedv Apr 11, 2022 •
edited

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This is done to allow interactively work with subprocesses if nothing is "touched".

This way to can make it work:

#!/usr/bin/env zx

// sleep() already defined in zx

let p = $`read var; echo "$var";`
let stdin = p.stdin // force piped mode.

await sleep(1000);

stdin.write('Hello, stdin!\n')

See http://go/gh/google/zx/blob/main/examples/interactive.mjs

Well, probably we can create separate API for setting inherited stdin. Like

$`...`.inheritStdin()

windowsHide: true,
})

child.on('exit', code => {
child.on('close', () => {
if (piped) process.stdin.unpipe(child.stdin)
let output = new ProcessOutput({
code, stdout, stderr, combined,
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combined, message props are not declaredProcessOutput iface. The rest seems fine to me.

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Yes, message goes to the parent class. And combined is used inside toString() func.

message: `${stderr || '\n'} at ${__from}\n exit code: ${code}` + (exitCodeInfo(code) ? ' (' + exitCodeInfo(code) + ')' : '')
Expand All @@ -65,30 +73,23 @@ export function $(pieces, ...args) {
promise._resolved = true
})
})
})

let stdout = '', stderr = '', combined = '', piped = process.stdin.isTTY
if (piped) process.stdin.pipe(child.stdin)

function onStdout(data) {
if (verbose) process.stdout.write(data)
stdout += data
combined += data
}

function onStderr(data) {
if (verbose) process.stderr.write(data)
stderr += data
combined += data
}

child.stdout.on('data', onStdout)
child.stderr.on('data', onStderr)
promise._stop = () => {
child.stdout.off('data', onStdout)
child.stderr.off('data', onStderr)
let stdout = '', stderr = '', combined = ''
let onStdout = data => {
if (verbose) process.stdout.write(data)
stdout += data
combined += data
}
let onStderr = data => {
if (verbose) process.stderr.write(data)
stderr += data
combined += data
}
if (!promise._piped) child.stdout.on('data', onStdout)
child.stderr.on('data', onStderr)
promise.child = child
if (promise._postrun) promise._postrun()
}
promise.child = child
return promise
}

Expand Down Expand Up @@ -161,19 +162,26 @@ export function nothrow(promise) {

export class ProcessPromise extends Promise {
child = undefined
_stop = () => void 0
_nothrow = false
_resolved = false
_inheritStdin = true
_piped = false
_prerun = undefined
_postrun = undefined

get stdin() {
this._inheritStdin = false
this._run()
return this.child.stdin
}

get stdout() {
this._run()
return this.child.stdout
}

get stderr() {
this._run()
return this.child.stderr
}

Expand All @@ -183,25 +191,28 @@ export class ProcessPromise extends Promise {
.catch(p => p.exitCode)
}

then(onfulfilled, onrejected) {
if (this._run) this._run()
return super.then(onfulfilled, onrejected)
}

pipe(dest) {
if (typeof dest === 'string') {
throw new Error('The pipe() method does not take strings. Forgot $?')
}
if (this._resolved === true) {
if (dest instanceof ProcessPromise) {
nothrow(dest)
dest.child.kill()
}
throw new Error('The pipe() method shouldn\'t be called after promise is already resolved!')
}
this._stop()
this._piped = true
if (dest instanceof ProcessPromise) {
process.stdin.unpipe(dest.stdin)
this.stdout.pipe(dest.stdin)
dest._inheritStdin = false
dest._prerun = this._run
dest._postrun = () => this.stdout.pipe(dest.child.stdin)
return dest
} else {
this._postrun = () => this.stdout.pipe(dest)
return this
}
this.stdout.pipe(dest)
return this
}
}

Expand Down
1 change: 1 addition & 0 deletions test.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -141,6 +141,7 @@ import path from 'path'
out = await p.pipe($`less`)
} catch (err) {
console.log(err)
assert.equal(err.message, `The pipe() method shouldn't be called after promise is already resolved!`)
console.log('☝️ Error above is expected')
}
if (out) {
Expand Down