fix: don't unpack file duplicates

.changeset/hot-wombats-sort.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/cafs": patch
+---
+
+Don't unpack file duplicates to the content-addressable store.

packages/cafs/src/addFilesFromTarball.ts

@@ -14,9 +14,9 @@ export default async function (
   const extract = tar.extract()
   const filesIndex = {}
   await new Promise((resolve, reject) => {
-    extract.on('entry', async (header, fileStream, next) => {
-      const filename = header.name.substr(header.name.indexOf('/') + 1)
-      if (header.type !== 'file' || ignore(filename)) {
+    extract.on('entry', (header, fileStream, next) => {
+      const filename = header.name.substr(header.name.indexOf('/') + 1).replace(/\/\//g, '/')
+      if (header.type !== 'file' || ignore(filename) || filesIndex[filename]) {
         fileStream.resume()
         next()
         return

packages/cafs/test/index.ts

@@ -52,3 +52,19 @@ describe('checkFilesIntegrity()', () => {
     })).toBeFalsy()
   })
 })
+
+test('file names are normalized when unpacking a tarball', async () => {
+  const dest = tempy.directory()
+  console.log(dest)
+  const cafs = createCafs(dest)
+  const filesIndex = await cafs.addFilesFromTarball(
+    fs.createReadStream(path.join(__dirname, 'fixtures/colorize-semver-diff.tgz'))
+  )
+  expect(Object.keys(filesIndex).sort()).toStrictEqual([
+    'LICENSE',
+    'README.md',
+    'lib/index.d.ts',
+    'lib/index.js',
+    'package.json',
+  ])
+})