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

@@ -1,6 +1,7 @@
 #!/usr/bin/env node
 import { globbySync } from 'globby'
 import fs from 'node:fs'
+import getStdin from 'get-stdin'
 import sortPackageJson from './index.js'
 import Reporter from './reporter.js'
 
@@ -23,6 +24,7 @@ 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       Read package.json from stdin
   `,
   )
 }
@@ -57,6 +59,10 @@ function sortPackageJsonFiles(patterns, options) {
   reporter.printSummary()
 }
 
+async function sortPackageJsonFromStdin() {
+  console.log(sortPackageJson(await getStdin()))
+}
+
 function run() {
   const cliArguments = process.argv.slice(2)
 
@@ -74,6 +80,10 @@ function run() {
     return showVersion()
   }
 
+  if (cliArguments.some((argument) => argument === '--stdin')) {
+    return sortPackageJsonFromStdin()
+  }
+
   const patterns = []
   let isCheck = false
   let shouldBeQuiet = false

package.json

@@ -69,6 +69,8 @@
   "dependencies": {
     "detect-indent": "^7.0.1",
     "detect-newline": "^4.0.0",
+    "get-stdin": "^9.0.0",
+    "get-stream": "^6.0.1",
     "git-hooks-list": "^3.0.0",
     "globby": "^13.1.2",
     "is-plain-obj": "^4.1.0",

tests/cli.js

@@ -1,4 +1,6 @@
 import test from 'ava'
+import getStream from 'get-stream'
+import { spawn } from 'node:child_process'
 import fs from 'node:fs'
 import { cliScript, macro } from './_helpers.js'
 
@@ -488,3 +490,11 @@ test('run `cli --quiet` on 1 non-json file', macro.testCLI, {
   args: ['*/package.json', '--quiet'],
   message: 'Should output error message',
 })
+
+test('run `cli --stdin` piping a json file from stdin', async (t) => {
+  const cp = spawn('node', ['cli.js', '--stdin'])
+  cp.stdin.end(`{\n  "description": "Description",\n  "name": "Name"\n}\n\n`)
+
+  const out = await getStream(cp.stdout)
+  t.is(out, `{\n  "name": "Name",\n  "description": "Description"\n}\n\n`)
+})

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       Read 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       Read 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       Read 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       Read 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       Read package.json from stdin␊
           ␊
         `,
       },