From ad4f2db0a04c68f54ee6dc6b1b1ef52b7a861a63 Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Sun, 23 May 2021 21:56:56 -0700
Subject: [PATCH] Do not rimraf /, override with preserveRoot:false

---
 README.md        |  2 ++
 lib/index.js     | 20 ++++++++++----------
 lib/path-arg.js  | 24 ++++++++++++++++--------
 test/path-arg.js |  5 +++++
 4 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/README.md b/README.md
index b9403998..6a312d5b 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,8 @@ Options:
 * `tmp`: Temp folder to use to place files and folders for the Windows
   implementation.  Must be on the same physical device as the path being
   deleted.  Defaults to `dirname(f)`.
+* `preserveRoot`: If set to boolean `false`, then allow the recursive
+  removal of the root directory.  Otherwise, this is not allowed.
 
 Any other options are provided to the native Node.js `fs.rm` implementation
 when that is used.
diff --git a/lib/index.js b/lib/index.js
index 41111553..6f40b65e 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -8,14 +8,14 @@ const {rimrafPosix, rimrafPosixSync} = require('./rimraf-posix.js')
 const {useNative, useNativeSync} = require('./use-native.js')
 
 const rimraf = (path, opts) => {
-  path = pathArg(path)
+  path = pathArg(path, opts)
   opts = optsArg(opts)
   return useNative(opts) ? rimrafNative(path, opts)
     : rimrafManual(path, opts)
 }
 
 const rimrafSync = async (path, opts) => {
-  path = pathArg(path)
+  path = pathArg(path, opts)
   opts = optsArg(opts)
   return useNativeSync(opts) ? rimrafNativeSync(path, opts)
     : rimrafManualSync(path, opts)
@@ -25,33 +25,33 @@ rimraf.rimraf = rimraf
 rimraf.sync = rimraf.rimrafSync = rimrafSync
 
 const native = async (path, opts) =>
-  rimrafNative(pathArg(path), optsArg(opts))
+  rimrafNative(pathArg(path, opts), optsArg(opts))
 const nativeSync = (path, opts) =>
-  rimrafNativeSync(pathArg(path), optsArg(opts))
+  rimrafNativeSync(pathArg(path, opts), optsArg(opts))
 native.sync = nativeSync
 rimraf.native = native
 rimraf.nativeSync = nativeSync
 
 const manual = async (path, opts) =>
-  rimrafManual(pathArg(path), optsArg(opts))
+  rimrafManual(pathArg(path, opts), optsArg(opts))
 const manualSync = (path, opts) =>
-  rimrafManualSync(pathArg(path), optsArg(opts))
+  rimrafManualSync(pathArg(path, opts), optsArg(opts))
 manual.sync = manualSync
 rimraf.manual = manual
 rimraf.manualSync = manualSync
 
 const windows = async (path, opts) =>
-  rimrafWindows(pathArg(path), optsArg(opts))
+  rimrafWindows(pathArg(path, opts), optsArg(opts))
 const windowsSync = (path, opts) =>
-  rimrafWindowsSync(pathArg(path), optsArg(opts))
+  rimrafWindowsSync(pathArg(path, opts), optsArg(opts))
 windows.sync = windowsSync
 rimraf.windows = windows
 rimraf.windowsSync = windowsSync
 
 const posix = async (path, opts) =>
-  rimrafPosix(pathArg(path), optsArg(opts))
+  rimrafPosix(pathArg(path, opts), optsArg(opts))
 const posixSync = (path, opts) =>
-  rimrafPosixSync(pathArg(path), optsArg(opts))
+  rimrafPosixSync(pathArg(path, opts), optsArg(opts))
 posix.sync = posixSync
 rimraf.posix = posix
 rimraf.posixSync = posixSync
diff --git a/lib/path-arg.js b/lib/path-arg.js
index d57677de..905b36f5 100644
--- a/lib/path-arg.js
+++ b/lib/path-arg.js
@@ -1,18 +1,26 @@
 const platform = require('./platform.js')
 const { resolve, parse } = require('path')
-const pathArg = path => {
+const pathArg = (path, opts = {}) => {
   if (/\0/.test(path)) {
     // simulate same failure that node raises
-    throw Object.assign(
-      new TypeError('path must be a string without null bytes'),
-      {
-        path,
-        code: 'ERR_INVALID_ARG_VALUE',
-      }
-    )
+    const msg = 'path must be a string without null bytes'
+    throw Object.assign(new TypeError(msg), {
+      path,
+      code: 'ERR_INVALID_ARG_VALUE',
+    })
   }
 
   path = resolve(path)
+  const { root } = parse(path)
+
+  if (path === root && opts.preserveRoot !== false) {
+    const msg = 'refusing to remove root directory without preserveRoot:false'
+    throw Object.assign(new Error(msg), {
+      path,
+      code: 'ERR_PRESERVE_ROOT',
+    })
+  }
+
   if (platform === 'win32') {
     const badWinChars = /[*|"<>?:]/
     const {root} = parse(path)
diff --git a/test/path-arg.js b/test/path-arg.js
index 1be5e33a..5cef8cd3 100644
--- a/test/path-arg.js
+++ b/test/path-arg.js
@@ -37,3 +37,8 @@ if (platform === 'win32') {
     t.throws(() => pathArg(path), er)
   }
 }
+
+t.throws(() => pathArg('/'), { code: 'ERR_PRESERVE_ROOT' })
+t.throws(() => pathArg('/', { preserveRoot: null }),
+  { code: 'ERR_PRESERVE_ROOT' })
+t.equal(pathArg('/', { preserveRoot: false }), resolve('/'))