fix: Retarget symlink only on non-windows, rerun exe otherwise

CHANGELOG.md

@@ -26,8 +26,6 @@
 
 * Create symlink properly when installed globally ([60f7861](https://github.com/prantlf/node-newchanges/commit/60f786189f43428292e33cdb2ad746091c11b00a))
 
-# Changes
-
 ## 2023-10-26 (0.0.1)
 
 Initial release

README.md

@@ -3,16 +3,16 @@
 [![Latest version](https://img.shields.io/npm/v/newchanges)
  ![Dependency status](https://img.shields.io/librariesio/release/npm/newchanges)
 ](https://www.npmjs.com/package/newchanges)
-[![Coverage](https://codecov.io/gh/prantlf/node-newchanges/branch/master/graph/badge.svg)](https://codecov.io/gh/prantlf/node-newchanges)
 
 Creates or updates the changelog file from commit messages formatted according to [Conventional Commits]. Installs [newchanges] in [Node.js] environments.
 
 ## Installation
 
-This package is usually installed globally, so that you can use the `newchanges` executable:
+This package is usually installed globally, so that you can use the `newchanges` executable from any directory. You can install it during the first usage with `npx` too:
 
 ```sh
 $ npm i -g newchanges
+$ npx newchanges ...
 ```
 
 Make sure, that you use [Node.js] version 18 or newer.

bin/newchanges.js

@@ -1,7 +1,8 @@
 #!/usr/bin/env node
 
+import { spawn } from 'child_process'
 import debug from 'debug'
-import { access, symlink, unlink } from 'fs/promises'
+import { access, lstat, symlink, unlink } from 'fs/promises'
 import { platform } from 'os'
 import { dirname, join } from 'path'
 import { fileURLToPath } from 'url'
@@ -11,7 +12,26 @@ const __dirname = dirname(__filename)
 const exists = file => access(file).then(() => true, () => false)
 const log = debug('newchanges')
 
-try {
+async function findExe(name) {
+  const exe = join(__dirname, '..', platform() != 'win32' ? name : `${name}.exe`)
+  if (!await exists(exe)) {
+    log('exe "%s"', exe)
+    throw new Error('missing executable')
+  }
+  return exe
+}
+
+function runExe(exe) {
+  const [,, ...args] = process.argv
+  log('run "%s" with %d args', exe, args.length)
+  return new Promise((resolve, reject) =>
+    spawn(exe, args, { stdio: 'inherit' })
+      .on('error', reject)
+      .on('exit', code => code ? reject(code) : resolve())
+  )
+}
+
+async function findBin() {
   // installed locally
   let bin = join(__dirname, '..', '..', '.bin')
   log('local bin "%s"', bin)
@@ -26,17 +46,46 @@ try {
     }
     if (!await exists(bin)) throw new Error('cannot find bin directory')
   }
+  return bin
+}
 
-  const exe = join(__dirname, '..', platform() != 'win32' ? 'newchanges' : `newchanges.exe`)
-  log('exe "%s"', exe)
-  if (!await exists(exe)) throw new Error('missing executable')
-  const link = join(bin, 'newchanges')
-  log('unlink "%s"', link)
-  await unlink(link)
-  log('link "%s"', link)
-  await symlink(exe, link, 'junction')
-  console.log('installation finished, re-run the same command')
+async function replaceLink(bin, name, exe) {
+  const link = join(bin, name)
+  log('stat "%s"', link)
+  const { mode } = await lstat(link)
+  if (mode & 0o222) {
+    log('unlink "%s"', link)
+    await unlink(link)
+    log('link "%s"', link)
+    await symlink(exe, link, 'junction')
+    return true
+  } else {
+    log('not writable')
+  }
+}
+
+async function runAndReplaceLink(name) {
+  const exe = await findExe(name)
+  if (platform() != 'win32') {
+    const bin = await findBin()
+    await replaceLink(bin, name, exe)
+  }
+  await runExe(exe)
+}
+
+function reportError(err) {
+  let code
+  if (typeof err !== 'number') {
+    console.error(err)
+    code = 1
+  } else {
+    code = err
+  }
+  process.exitCode = code
+}
+
+try {
+  await runAndReplaceLink('newchanges')
 } catch (err) {
-  console.error(err)
-  process.exitCode = 1
+  reportError(err)
 }