Changed the contract of DefaultDirectorySearcher in two significant ways:

* `search()` takes an array of `Directory` objects rather than an individual object.
* `options.didSearchPaths` now takes the `Directory` in addition to the `count` as an argument.

spec/workspace-spec.coffee

@@ -978,7 +978,8 @@ describe "Workspace", ->
               ]
             onFakeSearchCreated = (fakeSearch) ->
               fakeSearch.options.didMatch(searchResult)
-              fakeSearch.options.didSearchPaths(numPathsToPretendToSearchInCustomDirectorySearcher)
+              directory1 = atom.project.getDirectories()[atom.project.getPaths().indexOf(dir1)]
+              fakeSearch.options.didSearchPaths(directory1, numPathsToPretendToSearchInCustomDirectorySearcher)
               fakeSearch.hoistedResolve()
 
             resultPaths = []

src/default-directory-searcher.coffee

@@ -4,9 +4,7 @@ Task = require './task'
 #
 # Implements thenable so it can be used with `Promise.all()`.
 class DirectorySearch
-  # Public: Creates a new DirectorySearch that will not start running until the
-  # `emitter` that is private to this file emits an event with the specified `id`.
-  constructor: (rootPath, regex, options) ->
+  constructor: (directory, regex, options) ->
     scanHandlerOptions =
       ignoreCase: regex.ignoreCase
       inclusions: options.inclusions
@@ -17,10 +15,10 @@ class DirectorySearch
     @task = new Task(require.resolve('./scan-handler'))
     @task.on 'scan:result-found', options.didMatch
     @task.on 'scan:file-error', options.didError
-    @task.on 'scan:paths-searched', options.didSearchPaths
+    @task.on 'scan:paths-searched', (count) -> options.didSearchPaths(directory, count)
     @promise = new Promise (resolve, reject) =>
       @task.on('task:cancelled', reject)
-      @task.start([rootPath], regex.source, scanHandlerOptions, resolve)
+      @task.start([directory.getPath()], regex.source, scanHandlerOptions, resolve)
 
   # Public: Implementation of `then()` to satisfy the *thenable* contract.
   # This makes it possible to use a `DirectorySearch` with `Promise.all()`.
@@ -66,6 +64,7 @@ class DefaultDirectorySearcher
   #         * `range` {Range} Identifies the matching region in the file. (Likely as an array of numeric arrays.)
   #   * `didError` {Function} call with an Error if there is a problem during the search.
   #   * `didSearchPaths` {Function} periodically call with the number of paths searched thus far.
+  #   This takes two arguments: the `Directory` and the count.
   #   * `inclusions` {Array} of glob patterns (as strings) to search within. Note that this
   #   array may be empty, indicating that all files should be searched.
   #
@@ -80,15 +79,16 @@ class DefaultDirectorySearcher
   # Returns a *thenable* `DirectorySearch` that includes a `cancel()` method. If `cancel()` is
   # invoked before the `DirectorySearch` is determined, it will reject the `DirectorySearch`.
   search: (directories, regex, options) ->
-    rootPaths = directories.map (directory) -> directory.getPath()
+    # Make a mutable copy of the directories array.
+    directories = directories.slice(0)
     isCancelled = false
     promise = new Promise (resolve, reject) ->
       run = ->
         if isCancelled
           reject()
-        else if rootPaths.length
-          rootPath = rootPaths.shift()
-          thenable = new DirectorySearch(rootPath, regex, options)
+        else if directories.length
+          directory = directories.shift()
+          thenable = new DirectorySearch(directory, regex, options)
           thenable.then(run, reject)
         else
           resolve()

src/workspace.coffee

@@ -811,15 +811,20 @@ class Workspace extends Model
       iterator = options
       options = {}
 
-    # Find a searcher for every Directory in the project.
-    searchersAndDirectories = []
+    # Find a searcher for every Directory in the project. Each searcher that is matched
+    # will be associated with an Array of Directory objects in the Map.
+    directoriesForSearcher = new Map()
     for directory in atom.project.getDirectories()
       searcher = @defaultDirectorySearcher
       for directorySearcher in @directorySearchers
         if directorySearcher.canSearchDirectory(directory)
           searcher = directorySearcher
           break
-      searchersAndDirectories.push({searcher, directory})
+      directories = directoriesForSearcher.get(searcher)
+      unless directories
+        directories = []
+        directoriesForSearcher.set(searcher, directories)
+      directories.push(directory)
 
     # Define the onPathsSearched callback.
     if _.isFunction(options.onPathsSearched)
@@ -838,22 +843,23 @@ class Workspace extends Model
     else
       onPathsSearched = ->
 
+    # Build up the options object that will be shared by all searchers.
+    searchOptions =
+      inclusions: options.paths or []
+      includeHidden: true
+      excludeVcsIgnores: atom.config.get('core.excludeVcsIgnoredPaths')
+      exclusions: atom.config.get('core.ignoredNames')
+      follow: atom.config.get('core.followSymlinks')
+      didMatch: (result) ->
+        iterator(result) unless atom.project.isPathModified(result.filePath)
+      didError: (error) ->
+        iterator(null, error)
+      didSearchPaths: onPathsSearched
+
     # Kick off all of the searches and unify them into one Promise.
     allSearches = []
-    for entry in searchersAndDirectories
-      {searcher, directory} = entry
-      searchOptions =
-        inclusions: options.paths or []
-        includeHidden: true
-        excludeVcsIgnores: atom.config.get('core.excludeVcsIgnoredPaths')
-        exclusions: atom.config.get('core.ignoredNames')
-        follow: atom.config.get('core.followSymlinks')
-        didMatch: (result) ->
-          iterator(result) unless atom.project.isPathModified(result.filePath)
-        didError: (error) ->
-          iterator(null, error)
-        didSearchPaths: onPathsSearched.bind(undefined, directory)
-      directorySearcher = searcher.search([directory], regex, searchOptions)
+    directoriesForSearcher.forEach (directories, searcher) ->
+      directorySearcher = searcher.search(directories, regex, searchOptions)
       allSearches.push(directorySearcher)
     searchPromise = Promise.all(allSearches)