Add symlink support (Fixes #42)

Author: JonAbrams

README.md

@@ -72,12 +72,24 @@ This is just [glob-watcher]
   - mode - Specify the mode the files should be created with. Default is the mode of the input file (file.stat.mode)
 - Returns a Readable/Writable stream.
 - On write the stream will save the [vinyl] File to disk at the folder/cwd specified.
-- After writing the file to disk, it will be emitted from the stream so you can keep piping these around
-- The file will be modified after being written to this stream
+- After writing the file to disk, it will be emitted from the stream so you can keep piping these around.
+- The file will be modified after being written to this stream:
   - `cwd`, `base`, and `path` will be overwritten to match the folder
   - `stat.mode` will be overwritten if you used a mode parameter
   - `contents` will have it's position reset to the beginning if it is a stream
 
+### symlink(folder[, opt])
+
+- Takes a folder path as the first argument.
+- First argument can also be a function that takes in a file and returns a folder path.
+- Possible options for the second argument:
+  - cwd - Specify the working directory the folder is relative to. Default is `process.cwd()`
+- Returns a Readable/Writable stream.
+- On write the stream will create a symbolic link (i.e. symlink) on disk at the folder/cwd specified.
+- After creating the symbolic link, it will be emitted from the stream so you can keep piping these around.
+- The file will be modified after being written to this stream:
+  - `cwd`, `base`, and `path` will be overwritten to match the folder
+
 [glob-stream]: https://github.com/wearefractal/glob-stream
 [node-glob]: https://github.com/isaacs/node-glob
 [gaze]: https://github.com/shama/gaze

index.js

@@ -3,5 +3,6 @@
 module.exports = {
   src: require('./lib/src'),
   dest: require('./lib/dest'),
+  symlink: require('./lib/symlink'),
   watch: require('glob-watcher')
 };

lib/symlink/index.js

@@ -0,0 +1,61 @@
+'use strict';
+
+var assign = require('object-assign');
+var path = require('path');
+var through2 = require('through2');
+var mkdirp = require('mkdirp');
+var fs = require('graceful-fs');
+
+function symlink(outFolder, opt) {
+  opt = opt || {};
+  if (typeof outFolder !== 'string' && typeof outFolder !== 'function') {
+    throw new Error('Invalid output folder');
+  }
+
+  var options = assign({
+    cwd: process.cwd()
+  }, opt);
+
+  var cwd = path.resolve(options.cwd);
+
+  function linkFile (file, enc, cb) {
+    var basePath;
+    if (typeof outFolder === 'string') {
+      basePath = path.resolve(cwd, outFolder);
+    }
+    if (typeof outFolder === 'function') {
+      basePath = path.resolve(cwd, outFolder(file));
+    }
+    var writePath = path.resolve(basePath, file.relative);
+    var writeFolder = path.dirname(writePath);
+    var srcPath = file.path;
+
+    // wire up new properties
+    file.stat = file.stat ? file.stat : new fs.Stats();
+    file.stat.mode = (options.mode || file.stat.mode);
+    file.cwd = cwd;
+    file.base = basePath;
+    file.path = writePath;
+
+    // mkdirp the folder the file is going in
+    mkdirp(writeFolder, function(err){
+      if (err) {
+        return cb(err);
+      }
+      fs.symlink(srcPath, writePath, function (err) {
+        if (err && err.code !== 'EEXIST') {
+          return cb(err);
+        }
+
+        cb(null, file);
+      });
+    });
+  }
+
+  var stream = through2.obj(linkFile);
+  // TODO: option for either backpressure or lossy
+  stream.resume();
+  return stream;
+}
+
+module.exports = symlink;