feat: add --stdin flag

README.md

@@ -89,6 +89,14 @@ $ sort-package-json "**/package.json" --check --quiet
 $ sort-package-json "**/package.json" --quiet
 ```
 
+### `--stdin` flag
+
+To read from `stdin` and output the result to `stdout` use the `--stdin` flag.
+
+```bash
+$ cat package.json | sort-package-json --stdin
+```
+
 ## API
 
 ### Install

cli.js

@@ -4,6 +4,18 @@ import fs from 'node:fs'
 import sortPackageJson from './index.js'
 import Reporter from './reporter.js'
 
+/** @param {import("node:stream").Stream} stream */
+async function streamToString(stream) {
+ // see https://stackoverflow.com/a/63361543/6051261
+ const chunks = []
+
+ for await (const chunk of stream) {
+ chunks.push(Buffer.from(chunk))
+ }
+
+ return Buffer.concat(chunks).toString('utf-8')
+}
+
 function showVersion() {
  const { name, version } = JSON.parse(
  fs.readFileSync(new URL('package.json', import.meta.url)),
@@ -23,6 +35,7 @@ If file/glob is omitted, './package.json' file will be processed.
  -q, --quiet Don't output success messages
  -h, --help Display this help
  -v, --version Display the package version
+ --stdin Reads package.json from stdin
  `,
  )
 }
@@ -57,6 +70,10 @@ function sortPackageJsonFiles(patterns, options) {
  reporter.printSummary()
 }
 
+async function sortPackageJsonFromStdin() {
+ console.log(sortPackageJson(await streamToString(process.stdin)))
+}
+
 function run() {
  const cliArguments = process.argv.slice(2)
 
@@ -74,6 +91,10 @@ function run() {
  return showVersion()
  }
 
+ if (cliArguments.some((argument) => argument === '--stdin')) {
+ return sortPackageJsonFromStdin()
+ }
+
  const patterns = []
  let isCheck = false
  let shouldBeQuiet = false

tests/snapshots/cli.js.md

@@ -25,6 +25,7 @@ Generated by [AVA](https://avajs.dev).
  -q, --quiet Don't output success messages␊
  -h, --help Display this help␊
  -v, --version Display the package version␊
+ --stdin Reads package.json from stdin␊
  ␊
  `,
  },
@@ -52,6 +53,7 @@ Generated by [AVA](https://avajs.dev).
  -q, --quiet Don't output success messages␊
  -h, --help Display this help␊
  -v, --version Display the package version␊
+ --stdin Reads package.json from stdin␊
  ␊
  `,
  },
@@ -78,6 +80,7 @@ Generated by [AVA](https://avajs.dev).
  -q, --quiet Don't output success messages␊
  -h, --help Display this help␊
  -v, --version Display the package version␊
+ --stdin Reads package.json from stdin␊
  ␊
  `,
  },
@@ -105,6 +108,7 @@ Generated by [AVA](https://avajs.dev).
  -q, --quiet Don't output success messages␊
  -h, --help Display this help␊
  -v, --version Display the package version␊
+ --stdin Reads package.json from stdin␊
  ␊
  `,
  },
@@ -202,6 +206,7 @@ Generated by [AVA](https://avajs.dev).
  -q, --quiet Don't output success messages␊
  -h, --help Display this help␊
  -v, --version Display the package version␊
+ --stdin Reads package.json from stdin␊
  ␊
  `,
  },