npm@npmcli/run-script
Run a lifecycle script for a package (descendant of npm-lifecycle)
USAGE
const runScript = require('@npmcli/run-script')
runScript({
// required, the script to run
event: 'install',
// extra args to pass to the command, defaults to []
args: [],
// required, the folder where the package lives
path: '/path/to/package/folder',
// optional, these paths will be put at the beginning of `$PATH`, even
// after run-script adds the node_modules/.bin folder(s) from
// `process.cwd()`. This is for commands like `npm init`, `npm exec`,
// and `npx` to make sure manually installed packages come before
// anything that happens to be in the tree in `process.cwd()`.
binPaths: [
'/path/to/npx/node_modules/.bin',
'/path/to/npm/prefix/node_modules/.bin',
],
// optional, defaults to /bin/sh on unix, or cmd.exe on windows
scriptShell: '/bin/bash',
// optional, passed directly to `@npmcli/promise-spawn` which defaults it to true
// return stdout and stderr as strings rather than buffers
stdioString: false,
// optional, additional environment variables to add
// note that process.env IS inherited by default
// Always set:
// - npm_package_json The package.json file in the folder
// - npm_lifecycle_event The event that this is being run for
// - npm_lifecycle_script The script being run
// The fields described in https://github.com/npm/rfcs/pull/183
env: {
npm_package_from: 'foo@bar',
npm_package_resolved: 'https://registry.npmjs.org/foo/-/foo-1.2.3.tgz',
npm_package_integrity: 'sha512-foobarbaz',
},
// defaults to 'pipe'. Can also pass an array like you would to node's
// exec or spawn functions. Note that if it's anything other than
// 'pipe' then the stdout/stderr values on the result will be missing.
// npm cli sets this to 'inherit' for explicit run-scripts (test, etc.)
// but leaves it as 'pipe' for install scripts that run in parallel.
stdio: 'inherit',
// print the package id and script, and the command to be run, like:
// > somepackage@1.2.3 postinstall
// > make all-the-things
})
.then(({ code, signal, stdout, stderr, pkgid, path, event, script }) => {
// do something with the results
})
.catch(er => {
// command did not work.
// er is decorated with:
// - code
// - signal
// - stdout
// - stderr
// - path
// - pkgid (name@version string)
// - event
// - script
})API
Call the exported runScript function with an options object.
Returns a promise that resolves to the result of the execution. Promise rejects if the execution fails (exits non-zero) or has any other error. Rejected errors are decorated with the same values as the result object.
If the stdio options mean that it'll have a piped stdin, then the stdin is ended immediately on the child process. If stdin is shared with the parent terminal, then it is up to the user to end it, of course.
Results
codeProcess exit codesignalProcess exit signalstdoutstdout data (Buffer, or String whenstdioStringset to true)stderrstderr data (Buffer, or String whenstdioStringset to true)pathPath to the package executing its scripteventLifecycle event being runscriptCommand being run
If stdio is inherit this package will emit a banner with the package
name and version, event name, and script command to be run, and send it
to proc-log.output.standard. Consuming
libraries can decide whether or not to display this.
Options
pathRequired. The path to the package having its script run.eventRequired. The event being executed.argsOptional, default[]. Extra arguments to pass to the script.envOptional, object of fields to add to the environment of the subprocess. Note that process.env IS inherited by default These are always set:npm_package_jsonThe package.json file in the foldernpm_lifecycle_eventThe event that this is being run fornpm_lifecycle_scriptThe script being run- The
package.jsonfields described in RFC183.
scriptShellOptional, defaults to/bin/shon Unix, defaults toenv.ComSpecorcmdon Windows. Custom script to use to execute the command.stdioOptional, defaults to'pipe'. The same as thestdioargument passed tochild_processfunctions in Node.js. Note that if a stdio output is set to anything other thanpipe, it will not be present in the result/error object.cmdOptional. Override the script from thepackage.jsonwith something else, which will be run in an otherwise matching environment.stdioStringOptional, passed directly to@npmcli/promise-spawnwhich defaults it totrue. Return string values forstderrandstdoutrather than Buffers.
Note that this does not run pre-event and post-event scripts. The caller has to manage that process themselves.
Differences from npm-lifecycle
This is an implementation to satisfy RFC 90, RFC 77, and RFC 73.
Apart from those behavior changes in npm v7, this is also just refresh of the codebase, with modern coding techniques and better test coverage.
Functionally, this means:
- Output is not dumped to the top level process's stdio by default.
- Less stuff is put into the environment.
- It is not opinionated about logging. (So, at least with the logging
framework in npm v7.0 and before, the caller has to call
log.disableProgress()andlog.enableProgress()at the appropriate times, if necessary.) - The directory containing the
nodeexecutable is never added to thePATHenvironment variable. (Ie,--scripts-prepend-node-pathis effectively always set tofalse.) Doing so causes more unintended side effects than it ever prevented. - Hook scripts are not run by this module. If the caller wishes to run
hook scripts, then they can override the default package script with an
explicit
cmdoption pointing to thenode_modules/.hook/${event}script.
Escaping
In order to ensure that arguments are handled consistently, this module writes a temporary script file containing the command as it exists in the package.json, followed by the user supplied arguments having been escaped to ensure they are processed as literal strings. We then instruct the shell to execute the script file, and when the process exits we remove the temporary file.
In Windows, when the shell is cmd, and when the initial command in the script
is a known batch file (i.e. something.cmd) we double escape additional
arguments so that the shim scripts npm installs work correctly.
The actual implementation of the escaping is in lib/escape.js.