Commit dd5e07f
child_process: attach child in promisification
This commit updates the custom exec() and execFile()
promisification to attach the ChildProcess instance to the
returned Promise.
PR-URL: #28325
Fixes: #28244
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Wyatt Preul <wpreul@gmail.com>1 parent 632fc1f commit dd5e07f
3 files changed
Lines changed: 42 additions & 21 deletions
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -214,10 +214,11 @@ Unlike the exec(3) POSIX system call, `child_process.exec()` does not replace | |||
| 214 | 214 | the existing process and uses a shell to execute the command. | |
| 215 | 215 | ||
| 216 | 216 | If this method is invoked as its [`util.promisify()`][]ed version, it returns | |
| 217 | - a `Promise` for an `Object` with `stdout` and `stderr` properties. In case of an | ||
| 218 | - error (including any error resulting in an exit code other than 0), a rejected | ||
| 219 | - promise is returned, with the same `error` object given in the callback, but | ||
| 220 | - with an additional two properties `stdout` and `stderr`. | ||
| 217 | + a `Promise` for an `Object` with `stdout` and `stderr` properties. The returned | ||
| 218 | + `ChildProcess` instance is attached to the `Promise` as a `child` property. In | ||
| 219 | + case of an error (including any error resulting in an exit code other than 0), a | ||
| 220 | + rejected promise is returned, with the same `error` object given in the | ||
| 221 | + callback, but with an additional two properties `stdout` and `stderr`. | ||
| 221 | 222 | ||
| 222 | 223 | ```js | |
| 223 | 224 | const util = require('util'); | |
@@ -295,9 +296,10 @@ stderr output. If `encoding` is `'buffer'`, or an unrecognized character | |||
| 295 | 296 | encoding, `Buffer` objects will be passed to the callback instead. | |
| 296 | 297 | ||
| 297 | 298 | If this method is invoked as its [`util.promisify()`][]ed version, it returns | |
| 298 | - a `Promise` for an `Object` with `stdout` and `stderr` properties. In case of an | ||
| 299 | - error (including any error resulting in an exit code other than 0), a rejected | ||
| 300 | - promise is returned, with the same `error` object given in the | ||
| 299 | + a `Promise` for an `Object` with `stdout` and `stderr` properties. The returned | ||
| 300 | + `ChildProcess` instance is attached to the `Promise` as a `child` property. In | ||
| 301 | + case of an error (including any error resulting in an exit code other than 0), a | ||
| 302 | + rejected promise is returned, with the same `error` object given in the | ||
| 301 | 303 | callback, but with an additional two properties `stdout` and `stderr`. | |
| 302 | 304 | ||
| 303 | 305 | ```js | |
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -149,17 +149,24 @@ function exec(command, options, callback) { | |||
| 149 | 149 | ||
| 150 | 150 | const customPromiseExecFunction = (orig) => { | |
| 151 | 151 | return (...args) => { | |
| 152 | - return new Promise((resolve, reject) => { | ||
| 153 | - orig(...args, (err, stdout, stderr) => { | ||
| 154 | - if (err !== null) { | ||
| 155 | - err.stdout = stdout; | ||
| 156 | - err.stderr = stderr; | ||
| 157 | - reject(err); | ||
| 158 | - } else { | ||
| 159 | - resolve({ stdout, stderr }); | ||
| 160 | - } | ||
| 161 | - }); | ||
| 152 | + let resolve; | ||
| 153 | + let reject; | ||
| 154 | + const promise = new Promise((res, rej) => { | ||
| 155 | + resolve = res; | ||
| 156 | + reject = rej; | ||
| 162 | 157 | }); | |
| 158 | + | ||
| 159 | + promise.child = orig(...args, (err, stdout, stderr) => { | ||
| 160 | + if (err !== null) { | ||
| 161 | + err.stdout = stdout; | ||
| 162 | + err.stderr = stderr; | ||
| 163 | + reject(err); | ||
| 164 | + } else { | ||
| 165 | + resolve({ stdout, stderr }); | ||
| 166 | + } | ||
| 167 | + }); | ||
| 168 | + | ||
| 169 | + return promise; | ||
| 163 | 170 | }; | |
| 164 | 171 | }; | |
| 165 | 172 | ||
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -8,25 +8,37 @@ const exec = promisify(child_process.exec); | |||
| 8 | 8 | const execFile = promisify(child_process.execFile); | |
| 9 | 9 | ||
| 10 | 10 | { | |
| 11 | - exec(`${process.execPath} -p 42`).then(common.mustCall((obj) => { | ||
| 11 | + const promise = exec(`${process.execPath} -p 42`); | ||
| 12 | + | ||
| 13 | + assert(promise.child instanceof child_process.ChildProcess); | ||
| 14 | + promise.then(common.mustCall((obj) => { | ||
| 12 | 15 | assert.deepStrictEqual(obj, { stdout: '42\n', stderr: '' }); | |
| 13 | 16 | })); | |
| 14 | 17 | } | |
| 15 | 18 | ||
| 16 | 19 | { | |
| 17 | - execFile(process.execPath, ['-p', '42']).then(common.mustCall((obj) => { | ||
| 20 | + const promise = execFile(process.execPath, ['-p', '42']); | ||
| 21 | + | ||
| 22 | + assert(promise.child instanceof child_process.ChildProcess); | ||
| 23 | + promise.then(common.mustCall((obj) => { | ||
| 18 | 24 | assert.deepStrictEqual(obj, { stdout: '42\n', stderr: '' }); | |
| 19 | 25 | })); | |
| 20 | 26 | } | |
| 21 | 27 | ||
| 22 | 28 | { | |
| 23 | - exec('doesntexist').catch(common.mustCall((err) => { | ||
| 29 | + const promise = exec('doesntexist'); | ||
| 30 | + | ||
| 31 | + assert(promise.child instanceof child_process.ChildProcess); | ||
| 32 | + promise.catch(common.mustCall((err) => { | ||
| 24 | 33 | assert(err.message.includes('doesntexist')); | |
| 25 | 34 | })); | |
| 26 | 35 | } | |
| 27 | 36 | ||
| 28 | 37 | { | |
| 29 | - execFile('doesntexist', ['-p', '42']).catch(common.mustCall((err) => { | ||
| 38 | + const promise = execFile('doesntexist', ['-p', '42']); | ||
| 39 | + | ||
| 40 | + assert(promise.child instanceof child_process.ChildProcess); | ||
| 41 | + promise.catch(common.mustCall((err) => { | ||
| 30 | 42 | assert(err.message.includes('doesntexist')); | |
| 31 | 43 | })); | |
| 32 | 44 | } | |
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