From 56d2be9a4143f0c7e66e623588379eab1d82fc6c Mon Sep 17 00:00:00 2001
From: Evan Wallace <evan.exe@gmail.com>
Date: Mon, 3 Aug 2020 08:54:55 -0700
Subject: [PATCH] fix #310: support symlinks with absolute paths

---
 CHANGELOG.md                |  6 ++++++
 internal/fs/fs.go           |  5 ++++-
 scripts/end-to-end-tests.js | 14 +++++++++++++-
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b3afe9edc14..f8b1335acd3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+* Support symlinks with absolute paths in `node_modules` ([#310](https://github.com/evanw/esbuild/issues/310))
+
+    Previously esbuild only supported symlinks with relative paths, not absolute paths. Adding support for absolute paths in symlinks fixes issues with esbuild and [pnpm](https://github.com/pnpm/pnpm) on Windows.
+
 ## 0.6.14
 
 * Add support for parsing top-level await ([#253](https://github.com/evanw/esbuild/issues/253))
diff --git a/internal/fs/fs.go b/internal/fs/fs.go
index 4b5bb9ebe33..69c2bb071b6 100644
--- a/internal/fs/fs.go
+++ b/internal/fs/fs.go
@@ -234,7 +234,10 @@ func (fs *realFS) ReadDirectory(dir string) map[string]Entry {
 					if err != nil {
 						continue // Skip over this entry
 					}
-					symlink = filepath.Clean(filepath.Join(dir, link))
+					if !filepath.IsAbs(link) {
+						link = filepath.Join(dir, link)
+					}
+					symlink = filepath.Clean(link)
 
 					// Re-run "lstat" on the symlink target
 					stat2, err2 := os.Lstat(symlink)
diff --git a/scripts/end-to-end-tests.js b/scripts/end-to-end-tests.js
index fa4743e7c83..1857f50ca5e 100644
--- a/scripts/end-to-end-tests.js
+++ b/scripts/end-to-end-tests.js
@@ -77,6 +77,18 @@
         'registry/node_modules/bar/index.js': `export const bar = 123`,
         'node_modules/foo/index.js': { symlink: `../../registry/node_modules/foo/index.js` },
       }),
+      test(['--bundle', 'in.js', '--outfile=node.js'], {
+        'in.js': `import {foo} from 'foo'; if (foo !== 123) throw 'fail'`,
+        'registry/node_modules/foo/index.js': `export {bar as foo} from 'bar'`,
+        'registry/node_modules/bar/index.js': `export const bar = 123`,
+        'node_modules/foo': { symlink: `TEST_DIR_ABS_PATH/registry/node_modules/foo` },
+      }),
+      test(['--bundle', 'in.js', '--outfile=node.js'], {
+        'in.js': `import {foo} from 'foo'; if (foo !== 123) throw 'fail'`,
+        'registry/node_modules/foo/index.js': `export {bar as foo} from 'bar'`,
+        'registry/node_modules/bar/index.js': `export const bar = 123`,
+        'node_modules/foo/index.js': { symlink: `TEST_DIR_ABS_PATH/registry/node_modules/foo/index.js` },
+      }),
     )
   }
 
@@ -793,7 +805,7 @@
             mkdirp.sync(path.dirname(filePath))
 
             // Optionally symlink the file if the test requests it
-            if (contents.symlink) await symlinkAsync(contents.symlink, filePath)
+            if (contents.symlink) await symlinkAsync(contents.symlink.replace('TEST_DIR_ABS_PATH', thisTestDir), filePath)
             else await writeFileAsync(filePath, contents)
           }