1 files changed, 57 insertions, 0 deletions
diff --git a/node_modules/bin-links/lib/link-gently.js b/node_modules/bin-links/lib/link-gently.js
new file mode 100644
index 000000000..75b157618
--- /dev/null
+++ b/node_modules/bin-links/lib/link-gently.js
@@ -0,0 +1,57 @@
+// if the thing isn't there, skip it
+// if there's a non-symlink there already, eexist
+// if there's a symlink already, pointing somewhere else, eexist
+// if there's a symlink already, pointing into our pkg, remove it first
+// then create the symlink
+
+const { promisify } = require('util')
+const { resolve, dirname } = require('path')
+const mkdirp = require('mkdirp-infer-owner')
+const fs = require('fs')
+const symlink = promisify(fs.symlink)
+const readlink = promisify(fs.readlink)
+const lstat = promisify(fs.lstat)
+const throwNonEnoent = er => { if (er.code !== 'ENOENT') throw er }
+
+// disable glob in our rimraf calls
+const rimraf = promisify(require('rimraf'))
+const rm = path => rimraf(path, { glob: false })
+
+const SKIP = Symbol('skip - missing or already installed')
+
+const linkGently = ({path, to, from, absFrom, force}) => {
+  // if the script or manpage isn't there, just ignore it.
+  // this arguably *should* be an install error of some sort,
+  // or at least a warning, but npm has always behaved this
+  // way in the past, so it'd be a breaking change
+  return Promise.all([
+    lstat(absFrom).catch(throwNonEnoent),
+    lstat(to).catch(throwNonEnoent),
+  ]).then(([stFrom, stTo]) => {
+    // not present in package, skip it
+    if (!stFrom)
+      return SKIP
+
+    // exists! maybe clobber if we can
+    if (stTo) {
+      if (!stTo.isSymbolicLink())
+        return force ? rm(to) : Promise.resolve()
+
+      return readlink(to).then(target => {
+        if (target === from)
+          return SKIP // skip it, already set up like we want it.
+
+        target = resolve(dirname(to), target)
+        if (target.indexOf(path) === 0 || force)
+          return rm(to)
+      })
+    } else {
+      // doesn't exist, dir might not either
+      return mkdirp(dirname(to))
+    }
+  })
+  // this will fail if we didn't remove it
+  .then(skip => skip !== SKIP && symlink(from, to, 'file').then(() => true))
+}
+
+module.exports = linkGently