From 44d9bb5fa1f9e3d3b985d69ced2400020992fb93 Mon Sep 17 00:00:00 2001
From: Zoltan Kochan <z@kochan.io>
Date: Sat, 24 Aug 2024 02:35:41 +0200
Subject: [PATCH] fix: don't throw an error if correct symlink already exists

---
 src/index.ts  | 22 ++++++++++++++++------
 test/async.ts | 19 +++++++++++++++++++
 test/sync.ts  | 19 +++++++++++++++++++
 3 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 728f892..4a5dc93 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -42,6 +42,7 @@ async function forceSymlink (
     renameTried?: boolean
   }
 ): Promise<{ reused: boolean, warn?: string }> {
+  let initialErr: Error
   try {
     await fs.symlink(target, path, symlinkType)
     return { reused: false }
@@ -60,9 +61,7 @@ async function forceSymlink (
         return { reused: false }
       case 'EEXIST':
       case 'EISDIR':
-        if (opts?.overwrite === false) {
-          throw err
-        }
+        initialErr = err
         // If the target file already exists then we proceed.
         // Additional checks are done below.
         break
@@ -75,6 +74,9 @@ async function forceSymlink (
   try {
     linkString = await fs.readlink(path)
   } catch (err) {
+    if (opts?.overwrite === false) {
+      throw initialErr
+    }
     // path is not a link
     const parentDir = pathLib.dirname(path)
     let warn!: string
@@ -98,6 +100,9 @@ async function forceSymlink (
   if (target === linkString) {
     return { reused: true }
   }
+  if (opts?.overwrite === false) {
+    throw initialErr
+  }
   await fs.unlink(path)
   return await forceSymlink(target, path, opts)
 }
@@ -128,10 +133,12 @@ function forceSymlinkSync (
     renameTried?: boolean
   }
 ): { reused: boolean, warn?: string } {
+  let initialErr: Error
   try {
     symlinkSync(target, path, symlinkType)
     return { reused: false }
   } catch (err) {
+    initialErr = err
     switch ((<NodeJS.ErrnoException>err).code) {
       case 'ENOENT':
         try {
@@ -146,9 +153,6 @@ function forceSymlinkSync (
         return { reused: false }
       case 'EEXIST':
       case 'EISDIR':
-        if (opts?.overwrite === false) {
-          throw err
-        }
         // If the target file already exists then we proceed.
         // Additional checks are done below.
         break
@@ -161,6 +165,9 @@ function forceSymlinkSync (
   try {
     linkString = readlinkSync(path)
   } catch (err) {
+    if (opts?.overwrite === false) {
+      throw initialErr
+    }
     // path is not a link
     const parentDir = pathLib.dirname(path)
     let warn!: string
@@ -184,6 +191,9 @@ function forceSymlinkSync (
   if (target === linkString) {
     return { reused: true }
   }
+  if (opts?.overwrite === false) {
+    throw initialErr
+  }
   unlinkSync(path)
   return forceSymlinkSync(target, path, opts)
 }
diff --git a/test/async.ts b/test/async.ts
index 764a05b..8e288c7 100644
--- a/test/async.ts
+++ b/test/async.ts
@@ -40,6 +40,25 @@ test('do not rename target folder if overwrite is set to false', async (t) => {
   t.end()
 })
 
+test('do not fail if correct target folder already exists', async (t) => {
+  const temp = tempy.directory()
+  t.comment(`testing in ${temp}`)
+  process.chdir(temp)
+
+  await fs.mkdir('src')
+  await symlink('src', 'dest', { overwrite: false })
+
+  let err!: Error
+  try {
+    await symlink('src', 'dest', { overwrite: false })
+  } catch (_err) {
+    err = _err
+  }
+
+  t.equals(err, undefined)
+  t.end()
+})
+
 test('rename target file if it exists', async (t) => {
   const temp = tempy.directory()
   t.comment(`testing in ${temp}`)
diff --git a/test/sync.ts b/test/sync.ts
index ac5cf98..050c746 100644
--- a/test/sync.ts
+++ b/test/sync.ts
@@ -40,6 +40,25 @@ test('do not rename target folder if overwrite is set to false', async (t) => {
   t.end()
 })
 
+test('do not fail if correct target folder already exists', async (t) => {
+  const temp = tempy.directory()
+  t.comment(`testing in ${temp}`)
+  process.chdir(temp)
+
+  await fs.mkdir('src')
+  symlink.sync('src', 'dest', { overwrite: false })
+
+  let err!: Error
+  try {
+    symlink.sync('src', 'dest', { overwrite: false })
+  } catch (_err) {
+    err = _err
+  }
+
+  t.equals(err, undefined)
+  t.end()
+})
+
 test('rename target file if it exists', async (t) => {
   const temp = tempy.directory()
   t.comment(`testing in ${temp}`)