fix: make prepare have feature parity with legacy read-package-json

Full list of changes are as follows:
- ignore `directories.bin` if `bin` is present
- walk up filesystem to look for git directory
- log a warning for inaccessible bin entries but dont delete

These changes will be tracked in npm/statusboard#487 to see if they
should be made as breaking changes with npm 10.

These changes are tested by including `read-package-json` as a dev
dependency and running the `test/prepare.js` test suite against both
packages. This test can be removed once we have decided to make these
breaking changes.

Ref: npm/cli#6470
Fixes: #35

lib/index.js

@@ -44,6 +44,7 @@ class PackageJson {
     'authors',
     'readme',
     'mans',
+    'bin',
     'binDir',
     'gitHead',
     'fillTypes',

lib/normalize.js

@@ -3,10 +3,13 @@ const { glob } = require('glob')
 const normalizePackageBin = require('npm-normalize-package-bin')
 const normalizePackageData = require('normalize-package-data')
 const path = require('path')
+const log = require('proc-log')
+const git = require('@npmcli/git')
 
-const normalize = async (pkg, { strict, steps }) => {
+const normalize = async (pkg, { strict, steps, root }) => {
   const data = pkg.content
   const scripts = data.scripts || {}
+  const pkgId = `${data.name ?? ''}@${data.version ?? ''}`
 
   // remove attributes that start with "_"
   if (steps.includes('_attributes')) {
@@ -20,7 +23,7 @@ const normalize = async (pkg, { strict, steps }) => {
   // build the "_id" attribute
   if (steps.includes('_id')) {
     if (data.name && data.version) {
-      data._id = `${data.name}@${data.version}`
+      data._id = pkgId
     }
   }
 
@@ -158,7 +161,7 @@ const normalize = async (pkg, { strict, steps }) => {
   }
 
   // expand "directories.bin"
-  if (steps.includes('binDir') && data.directories?.bin) {
+  if (steps.includes('binDir') && data.directories?.bin && !data.bin) {
     const binsDir = path.resolve(pkg.path, path.join('.', path.join('/', data.directories.bin)))
     const bins = await glob('**', { cwd: binsDir })
     data.bin = bins.reduce((acc, binFile) => {
@@ -174,25 +177,28 @@ const normalize = async (pkg, { strict, steps }) => {
 
   // populate "gitHead" attribute
   if (steps.includes('gitHead') && !data.gitHead) {
+    const gitRoot = await git.find({ cwd: pkg.path, root })
     let head
-    try {
-      head = await fs.readFile(path.resolve(pkg.path, '.git/HEAD'), 'utf8')
-    } catch (err) {
+    if (gitRoot) {
+      try {
+        head = await fs.readFile(path.resolve(gitRoot, '.git/HEAD'), 'utf8')
+      } catch (err) {
       // do nothing
+      }
     }
     let headData
     if (head) {
       if (head.startsWith('ref: ')) {
         const headRef = head.replace(/^ref: /, '').trim()
-        const headFile = path.resolve(pkg.path, '.git', headRef)
+        const headFile = path.resolve(gitRoot, '.git', headRef)
         try {
           headData = await fs.readFile(headFile, 'utf8')
           headData = headData.replace(/^ref: /, '').trim()
         } catch (err) {
           // do nothing
         }
         if (!headData) {
-          const packFile = path.resolve(pkg.path, '.git/packed-refs')
+          const packFile = path.resolve(gitRoot, '.git/packed-refs')
           try {
             let refs = await fs.readFile(packFile, 'utf8')
             if (refs) {
@@ -271,11 +277,11 @@ const normalize = async (pkg, { strict, steps }) => {
   // in normalize-package-data if it had access to the file path.
   if (steps.includes('binRefs') && data.bin instanceof Object) {
     for (const key in data.bin) {
-      const binPath = path.resolve(pkg.path, data.bin[key])
       try {
-        await fs.access(binPath)
+        await fs.access(path.resolve(pkg.path, data.bin[key]))
       } catch {
-        delete data.bin[key]
+        log.warn('package-json', pkgId, `No bin file found at ${data.bin[key]}`)
+        // XXX: should a future breaking change delete bin entries that cannot be accessed?
       }
     }
   }

package.json

@@ -26,13 +26,16 @@
   "devDependencies": {
     "@npmcli/eslint-config": "^4.0.0",
     "@npmcli/template-oss": "4.15.1",
+    "read-package-json": "^6.0.3",
     "tap": "^16.0.1"
   },
   "dependencies": {
+    "@npmcli/git": "file:../git/npmcli-git-4.0.4.tgz",
     "glob": "^10.2.2",
     "json-parse-even-better-errors": "^3.0.0",
     "normalize-package-data": "^5.0.0",
-    "npm-normalize-package-bin": "^3.0.1"
+    "npm-normalize-package-bin": "^3.0.1",
+    "proc-log": "^3.0.0"
   },
   "repository": {
     "type": "git",