Merge branch 'master' into jl-bump-mdpv

2026-01-24 06:18:03 -05:00 · 2015-03-26 17:30:02 -07:00
parent 7d66288e1a 127e0fbf6b
commit dde7069d37
25 changed files with 351 additions and 148 deletions
--- a/10
+++ b/10
@@ -2,7 +2,7 @@
 # DESCRIPTION:    Image to build Atom and create a .rpm file

 # Base docker image
-FROM fedora:20
+FROM fedora:21

 # Install dependencies
 RUN yum install -y \
@@ -12,11 +12,11 @@ RUN yum install -y \
    glibc-devel \
    git-core \
    libgnome-keyring-devel \
-    rpmdevtools
+    rpmdevtools \
+    nodejs \
+    npm

-# Install node
-RUN curl -sL https://rpm.nodesource.com/setup | bash -
-RUN yum install -y nodejs
+RUN npm install -g npm@1.4.28 --loglevel error

 ADD . /atom
 WORKDIR /atom
--- a/LICENSE.md
+++ b/LICENSE.md
@@ -1,4 +1,4 @@
-Copyright (c) 2014 GitHub Inc.
+Copyright (c) 2015 GitHub Inc.

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
--- a/apm/package.json
+++ b/apm/package.json
@@ -6,6 +6,6 @@
    "url": "https://github.com/atom/atom.git"
  },
  "dependencies": {
-    "atom-package-manager": "0.149.0"
+    "atom-package-manager": "0.152.0"
  }
 }
--- a/build/tasks/set-version-task.coffee
+++ b/build/tasks/set-version-task.coffee
@@ -46,7 +46,7 @@ module.exports = (grunt) ->
        strings =
          CompanyName: 'GitHub, Inc.'
          FileDescription: 'Atom'
-          LegalCopyright: 'Copyright (C) 2014 GitHub, Inc. All rights reserved'
+          LegalCopyright: 'Copyright (C) 2015 GitHub, Inc. All rights reserved'
          ProductName: 'Atom'
          ProductVersion: version

--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
      "url": "http://github.com/atom/atom/raw/master/LICENSE.md"
    }
  ],
-  "atomShellVersion": "0.21.3",
+  "atomShellVersion": "0.22.2",
  "dependencies": {
    "async": "0.2.6",
    "atom-keymap": "^4",
@@ -64,8 +64,9 @@
    "space-pen": "3.8.2",
    "stacktrace-parser": "0.1.1",
    "temp": "0.8.1",
-    "text-buffer": "^5.0.2",
+    "text-buffer": "^5.1.0",
    "theorist": "^1.0.2",
+    "typescript-simple": "^1.0.0",
    "underscore-plus": "^1.6.6"
  },
  "packageDependencies": {
@@ -110,19 +111,19 @@
    "package-generator": "0.38.0",
    "release-notes": "0.52.0",
    "settings-view": "0.185.0",
-    "snippets": "0.85.0",
+    "snippets": "0.86.0",
    "spell-check": "0.55.0",
    "status-bar": "0.64.0",
    "styleguide": "0.44.0",
-    "symbols-view": "0.92.0",
+    "symbols-view": "0.93.0",
    "tabs": "0.67.0",
    "timecop": "0.31.0",
    "tree-view": "0.168.0",
    "update-package-dependencies": "0.9.0",
-    "welcome": "0.25.0",
+    "welcome": "0.26.0",
    "whitespace": "0.29.0",
    "wrap-guide": "0.31.0",
-    "language-c": "0.41.0",
+    "language-c": "0.42.0",
    "language-clojure": "0.13.0",
    "language-coffee-script": "0.39.0",
    "language-csharp": "0.5.0",
@@ -143,12 +144,12 @@
    "language-php": "0.21.0",
    "language-property-list": "0.8.0",
    "language-python": "0.32.0",
-    "language-ruby": "0.49.0",
+    "language-ruby": "0.50.0",
    "language-ruby-on-rails": "0.21.0",
    "language-sass": "0.36.0",
    "language-shellscript": "0.13.0",
    "language-source": "0.9.0",
-    "language-sql": "0.14.0",
+    "language-sql": "0.15.0",
    "language-text": "0.6.0",
    "language-todo": "0.17.0",
    "language-toml": "0.15.0",
--- a/script/cibuild
+++ b/script/cibuild
@@ -48,7 +48,7 @@ function removeNodeModules() {

 readEnvironmentVariables();
 removeNodeModules();
-cp.safeExec.bind(global, 'npm install npm', {cwd: path.resolve(__dirname, '..', 'build')}, function() {
+cp.safeExec.bind(global, 'npm install npm --loglevel error', {cwd: path.resolve(__dirname, '..', 'build')}, function() {
  cp.safeExec.bind(global, 'node script/bootstrap', function(error) {
    if (error)
      process.exit(1);
--- a/script/utils/verify-requirements.js
+++ b/script/utils/verify-requirements.js
@@ -57,7 +57,7 @@ function verifyNpm(cb) {
    var npmMajorVersion = +versionArray[0] || 0;
    var npmMinorVersion = +versionArray[1] || 0;
    if (npmMajorVersion === 1 && npmMinorVersion < 4)
-      cb("npm v1.4+ is required to build Atom.");
+      cb("npm v1.4+ is required to build Atom. Version " + npmVersion + " was detected.");
    else
      cb(null, "npm: v" + npmVersion);
  });
--- a/spec/compile-cache-spec.coffee
+++ b/spec/compile-cache-spec.coffee
@@ -3,26 +3,37 @@ CSON = require 'season'
 CoffeeCache = require 'coffee-cash'

 babel = require '../src/babel'
+typescript = require '../src/typescript'
 CompileCache = require '../src/compile-cache'

 describe "Compile Cache", ->
  describe ".addPathToCache(filePath)", ->
-    it "adds the path to the correct CSON, CoffeeScript, or babel cache", ->
+    it "adds the path to the correct CSON, CoffeeScript, babel or typescript cache", ->
      spyOn(CSON, 'readFileSync').andCallThrough()
      spyOn(CoffeeCache, 'addPathToCache').andCallThrough()
      spyOn(babel, 'addPathToCache').andCallThrough()
+      spyOn(typescript, 'addPathToCache').andCallThrough()

      CompileCache.addPathToCache(path.join(__dirname, 'fixtures', 'cson.cson'))
      expect(CSON.readFileSync.callCount).toBe 1
      expect(CoffeeCache.addPathToCache.callCount).toBe 0
      expect(babel.addPathToCache.callCount).toBe 0
+      expect(typescript.addPathToCache.callCount).toBe 0

      CompileCache.addPathToCache(path.join(__dirname, 'fixtures', 'coffee.coffee'))
      expect(CSON.readFileSync.callCount).toBe 1
      expect(CoffeeCache.addPathToCache.callCount).toBe 1
      expect(babel.addPathToCache.callCount).toBe 0
+      expect(typescript.addPathToCache.callCount).toBe 0

      CompileCache.addPathToCache(path.join(__dirname, 'fixtures', 'babel', 'babel-double-quotes.js'))
      expect(CSON.readFileSync.callCount).toBe 1
      expect(CoffeeCache.addPathToCache.callCount).toBe 1
      expect(babel.addPathToCache.callCount).toBe 1
+      expect(typescript.addPathToCache.callCount).toBe 0
+
+      CompileCache.addPathToCache(path.join(__dirname, 'fixtures', 'typescript', 'valid.ts'))
+      expect(CSON.readFileSync.callCount).toBe 1
+      expect(CoffeeCache.addPathToCache.callCount).toBe 1
+      expect(babel.addPathToCache.callCount).toBe 1
+      expect(typescript.addPathToCache.callCount).toBe 1
--- a/spec/default-directory-provider-spec.coffee
+++ b/spec/default-directory-provider-spec.coffee
@@ -15,8 +15,8 @@ describe "DefaultDirectoryProvider", ->
      provider = new DefaultDirectoryProvider()
      tmp = temp.mkdirSync()
      nonNormalizedPath = tmp + path.sep +  ".." + path.sep + path.basename(tmp)
-      expect(tmp.contains("..")).toBe false
-      expect(nonNormalizedPath.contains("..")).toBe true
+      expect(tmp.includes("..")).toBe false
+      expect(nonNormalizedPath.includes("..")).toBe true

      directory = provider.directoryForURISync(nonNormalizedPath)
      expect(directory.getPath()).toEqual tmp
--- a/spec/display-buffer-spec.coffee
+++ b/spec/display-buffer-spec.coffee
@@ -48,7 +48,6 @@ describe "DisplayBuffer", ->
      expect(displayBuffer.getLineCount()).toBe 100 + originalLineCount

    it "reassigns the scrollTop if it exceeds the max possible value after lines are removed", ->
-      displayBuffer.manageScrollPosition = true
      displayBuffer.setHeight(50)
      displayBuffer.setLineHeightInPixels(10)
      displayBuffer.setScrollTop(80)
@@ -287,7 +286,6 @@ describe "DisplayBuffer", ->
    it "sets ::scrollLeft to 0 and keeps it there when soft wrapping is enabled", ->
      displayBuffer.setDefaultCharWidth(10)
      displayBuffer.setWidth(85)
-      displayBuffer.manageScrollPosition = true

      displayBuffer.setSoftWrapped(false)
      displayBuffer.setScrollLeft(Infinity)
@@ -1174,7 +1172,6 @@ describe "DisplayBuffer", ->

  describe "::setScrollTop", ->
    beforeEach ->
-      displayBuffer.manageScrollPosition = true
      displayBuffer.setLineHeightInPixels(10)

    it "disallows negative values", ->
@@ -1196,7 +1193,6 @@ describe "DisplayBuffer", ->
    describe "when editor.scrollPastEnd is false", ->
      beforeEach ->
        atom.config.set("editor.scrollPastEnd", false)
-        displayBuffer.manageScrollPosition = true
        displayBuffer.setLineHeightInPixels(10)

      it "does not add the height of the view to the scroll height", ->
@@ -1209,7 +1205,6 @@ describe "DisplayBuffer", ->
    describe "when editor.scrollPastEnd is true", ->
      beforeEach ->
        atom.config.set("editor.scrollPastEnd", true)
-        displayBuffer.manageScrollPosition = true
        displayBuffer.setLineHeightInPixels(10)

      it "adds the height of the view to the scroll height", ->
@@ -1221,7 +1216,6 @@ describe "DisplayBuffer", ->

  describe "::setScrollLeft", ->
    beforeEach ->
-      displayBuffer.manageScrollPosition = true
      displayBuffer.setLineHeightInPixels(10)
      displayBuffer.setDefaultCharWidth(10)

@@ -1242,18 +1236,21 @@ describe "DisplayBuffer", ->

  describe "::scrollToScreenPosition(position, [options])", ->
    beforeEach ->
-      displayBuffer.manageScrollPosition = true
      displayBuffer.setLineHeightInPixels(10)
      displayBuffer.setDefaultCharWidth(10)
      displayBuffer.setHorizontalScrollbarHeight(0)
      displayBuffer.setHeight(50)
-      displayBuffer.setWidth(50)
+      displayBuffer.setWidth(150)

    it "sets the scroll top and scroll left so the given screen position is in view", ->
      displayBuffer.scrollToScreenPosition([8, 20])
      expect(displayBuffer.getScrollBottom()).toBe (9 + displayBuffer.getVerticalScrollMargin()) * 10
      expect(displayBuffer.getScrollRight()).toBe (20 + displayBuffer.getHorizontalScrollMargin()) * 10

+      displayBuffer.scrollToScreenPosition([8, 20])
+      expect(displayBuffer.getScrollBottom()).toBe (9 + displayBuffer.getVerticalScrollMargin()) * 10
+      expect(displayBuffer.getScrollRight()).toBe (20 + displayBuffer.getHorizontalScrollMargin()) * 10
+
    describe "when the 'center' option is true", ->
      it "vertically scrolls to center the given position vertically", ->
        displayBuffer.scrollToScreenPosition([8, 20], center: true)
@@ -1320,6 +1317,7 @@ describe "DisplayBuffer", ->
      expect(displayBuffer.getVisibleRowRange()).toEqual [0, 0]

    it "ends at last buffer row even if there's more space available", ->
+      displayBuffer.setHeight(150)
      displayBuffer.setScrollTop(60)

-      expect(displayBuffer.getVisibleRowRange()).toEqual [6, 13]
+      expect(displayBuffer.getVisibleRowRange()).toEqual [0, 13]
--- a/spec/fixtures/typescript/invalid.ts
+++ b/spec/fixtures/typescript/invalid.ts
@@ -0,0 +1 @@
+var foo = 123 123; // Syntax error
--- a/spec/fixtures/typescript/valid.ts
+++ b/spec/fixtures/typescript/valid.ts
@@ -0,0 +1,2 @@
+var inc = v => v + 1
+export = inc
--- a/spec/text-editor-component-spec.coffee
+++ b/spec/text-editor-component-spec.coffee
@@ -693,7 +693,7 @@ describe "TextEditorComponent", ->
  describe "cursor rendering", ->
    it "renders the currently visible cursors", ->
      cursor1 = editor.getLastCursor()
-      cursor1.setScreenPosition([0, 5])
+      cursor1.setScreenPosition([0, 5], autoscroll: false)

      wrapperNode.style.height = 4.5 * lineHeightInPixels + 'px'
      wrapperNode.style.width = 20 * lineHeightInPixels + 'px'
@@ -706,8 +706,8 @@ describe "TextEditorComponent", ->
      expect(cursorNodes[0].offsetWidth).toBe charWidth
      expect(cursorNodes[0].style['-webkit-transform']).toBe "translate(#{5 * charWidth}px, #{0 * lineHeightInPixels}px)"

-      cursor2 = editor.addCursorAtScreenPosition([8, 11])
-      cursor3 = editor.addCursorAtScreenPosition([4, 10])
+      cursor2 = editor.addCursorAtScreenPosition([8, 11], autoscroll: false)
+      cursor3 = editor.addCursorAtScreenPosition([4, 10], autoscroll: false)
      nextAnimationFrame()

      cursorNodes = componentNode.querySelectorAll('.cursor')
@@ -1524,7 +1524,7 @@ describe "TextEditorComponent", ->
      expect(inputNode.offsetLeft).toBe 0

      # In bounds, not focused
-      editor.setCursorBufferPosition([5, 4])
+      editor.setCursorBufferPosition([5, 4], autoscroll: false)
      nextAnimationFrame()
      expect(inputNode.offsetTop).toBe 0
      expect(inputNode.offsetLeft).toBe 0
@@ -1542,7 +1542,7 @@ describe "TextEditorComponent", ->
      expect(inputNode.offsetLeft).toBe 0

      # Out of bounds, not focused
-      editor.setCursorBufferPosition([1, 2])
+      editor.setCursorBufferPosition([1, 2], autoscroll: false)
      nextAnimationFrame()
      expect(inputNode.offsetTop).toBe 0
      expect(inputNode.offsetLeft).toBe 0
--- a/spec/text-editor-presenter-spec.coffee
+++ b/spec/text-editor-presenter-spec.coffee
@@ -351,11 +351,11 @@ describe "TextEditorPresenter", ->
          expectValues presenter.getState().hiddenInput, {top: 0, left: 0}

          expectStateUpdate presenter, -> editor.setCursorBufferPosition([11, 43])
-          expectValues presenter.getState().hiddenInput, {top: 50 - 10, left: 300 - 10}
+          expectValues presenter.getState().hiddenInput, {top: 11 * 10 - editor.getScrollTop(), left: 43 * 10 - editor.getScrollLeft()}

          newCursor = null
          expectStateUpdate presenter, -> newCursor = editor.addCursorAtBufferPosition([6, 10])
-          expectValues presenter.getState().hiddenInput, {top: (6 * 10) - 40, left: (10 * 10) - 70}
+          expectValues presenter.getState().hiddenInput, {top: (6 * 10) - editor.getScrollTop(), left: (10 * 10) - editor.getScrollLeft()}

          expectStateUpdate presenter, -> newCursor.destroy()
          expectValues presenter.getState().hiddenInput, {top: 50 - 10, left: 300 - 10}
@@ -1417,33 +1417,33 @@ describe "TextEditorPresenter", ->
          expect(stateForSelection(presenter, 1)).toBeUndefined()

          # moving into view
-          expectStateUpdate presenter, -> editor.getSelections()[1].setBufferRange([[2, 4], [2, 6]])
+          expectStateUpdate presenter, -> editor.getSelections()[1].setBufferRange([[2, 4], [2, 6]], autoscroll: false)
          expectValues stateForSelection(presenter, 1), {
            regions: [{top: 2 * 10, left: 4 * 10, width: 2 * 10, height: 10}]
          }

          # becoming empty
-          expectStateUpdate presenter, -> editor.getSelections()[1].clear()
+          expectStateUpdate presenter, -> editor.getSelections()[1].clear(autoscroll: false)
          expect(stateForSelection(presenter, 1)).toBeUndefined()

          # becoming non-empty
-          expectStateUpdate presenter, -> editor.getSelections()[1].setBufferRange([[2, 4], [2, 6]])
+          expectStateUpdate presenter, -> editor.getSelections()[1].setBufferRange([[2, 4], [2, 6]], autoscroll: false)
          expectValues stateForSelection(presenter, 1), {
            regions: [{top: 2 * 10, left: 4 * 10, width: 2 * 10, height: 10}]
          }

          # moving out of view
-          expectStateUpdate presenter, -> editor.getSelections()[1].setBufferRange([[3, 4], [3, 6]])
+          expectStateUpdate presenter, -> editor.getSelections()[1].setBufferRange([[3, 4], [3, 6]], autoscroll: false)
          expect(stateForSelection(presenter, 1)).toBeUndefined()

          # adding
-          expectStateUpdate presenter, -> editor.addSelectionForBufferRange([[1, 4], [1, 6]])
+          expectStateUpdate presenter, -> editor.addSelectionForBufferRange([[1, 4], [1, 6]], autoscroll: false)
          expectValues stateForSelection(presenter, 2), {
            regions: [{top: 1 * 10, left: 4 * 10, width: 2 * 10, height: 10}]
          }

          # moving added selection
-          expectStateUpdate presenter, -> editor.getSelections()[2].setBufferRange([[1, 4], [1, 8]])
+          expectStateUpdate presenter, -> editor.getSelections()[2].setBufferRange([[1, 4], [1, 8]], autoscroll: false)
          expectValues stateForSelection(presenter, 2), {
            regions: [{top: 1 * 10, left: 4 * 10, width: 4 * 10, height: 10}]
          }
--- a/spec/text-editor-spec.coffee
+++ b/spec/text-editor-spec.coffee
@@ -921,7 +921,6 @@ describe "TextEditor", ->

    describe "autoscroll", ->
      beforeEach ->
-        editor.manageScrollPosition = true
        editor.setVerticalScrollMargin(2)
        editor.setHorizontalScrollMargin(2)
        editor.setLineHeightInPixels(10)
@@ -971,9 +970,8 @@ describe "TextEditor", ->

      it "scrolls left when the last cursor gets closer than ::horizontalScrollMargin to the left of the editor", ->
        editor.setScrollRight(editor.getScrollWidth())
-        editor.setCursorScreenPosition([6, 62])
-
        expect(editor.getScrollRight()).toBe editor.getScrollWidth()
+        editor.setCursorScreenPosition([6, 62], autoscroll: false)

        editor.moveLeft()
        expect(editor.getScrollLeft()).toBe 59 * 10
@@ -994,6 +992,38 @@ describe "TextEditor", ->
        editor.undo()
        expect(editor.getScrollTop()).toBe 0

+      it "honors the autoscroll option on cursor and selection manipulation methods", ->
+        expect(editor.getScrollTop()).toBe 0
+        editor.addCursorAtScreenPosition([11, 11], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.addCursorAtBufferPosition([11, 11], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.setCursorScreenPosition([11, 11], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.setCursorBufferPosition([11, 11], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.addSelectionForBufferRange([[11, 11], [11, 11]], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.addSelectionForScreenRange([[11, 11], [11, 12]], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.setSelectedBufferRange([[11, 0], [11, 1]], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.setSelectedScreenRange([[11, 0], [11, 6]], autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+        editor.clearSelections(autoscroll: false)
+        expect(editor.getScrollTop()).toBe 0
+
+        editor.addSelectionForScreenRange([[0, 0], [0, 4]])
+
+        editor.getCursors()[0].setScreenPosition([11, 11], autoscroll: true)
+        expect(editor.getScrollTop()).toBeGreaterThan 0
+        editor.getCursors()[0].setBufferPosition([0, 0], autoscroll: true)
+        expect(editor.getScrollTop()).toBe 0
+        editor.getSelections()[0].setScreenRange([[11, 0], [11, 4]], autoscroll: true)
+        expect(editor.getScrollTop()).toBeGreaterThan 0
+        editor.getSelections()[0].setBufferRange([[0, 0], [0, 4]], autoscroll: true)
+        expect(editor.getScrollTop()).toBe 0
+
    describe '.logCursorScope()', ->
      beforeEach ->
        spyOn(atom.notifications, 'addInfo')
@@ -1254,7 +1284,6 @@ describe "TextEditor", ->
        expect(editor.getSelectedBufferRange()).toEqual [[0,0], [2,0]]

      it "autoscrolls to the selection", ->
-        editor.manageScrollPosition = true
        editor.setLineHeightInPixels(10)
        editor.setDefaultCharWidth(10)
        editor.setHeight(50)
@@ -1521,24 +1550,28 @@ describe "TextEditor", ->
        expect(selection1.getScreenRange()).toEqual [[2, 2], [3, 4]]

    describe ".setSelectedBufferRange(range)", ->
-      describe "when the 'autoscroll' option is true", ->
-        it "autoscrolls to the selection", ->
-          editor.manageScrollPosition = true
-          editor.setLineHeightInPixels(10)
-          editor.setDefaultCharWidth(10)
-          editor.setHeight(50)
-          editor.setWidth(50)
-          editor.setHorizontalScrollbarHeight(0)
+      it "autoscrolls the selection if it is last unless the 'autoscroll' option is false", ->
+        editor.setVerticalScrollMargin(2)
+        editor.setHorizontalScrollMargin(2)
+        editor.setLineHeightInPixels(10)
+        editor.setDefaultCharWidth(10)
+        editor.setHeight(70)
+        editor.setWidth(100)
+        editor.setHorizontalScrollbarHeight(0)

-          expect(editor.getScrollTop()).toBe 0
+        expect(editor.getScrollTop()).toBe 0

-          editor.setSelectedBufferRange([[5, 6], [6, 8]], autoscroll: true)
-          expect(editor.getScrollBottom()).toBe (7 + editor.getVerticalScrollMargin()) * 10
-          expect(editor.getScrollRight()).toBe 50
+        editor.setSelectedBufferRange([[5, 6], [6, 8]])
+        expect(editor.getScrollBottom()).toBe (7 + editor.getVerticalScrollMargin()) * 10
+        expect(editor.getScrollRight()).toBe (8 + editor.getHorizontalScrollMargin()) * 10

-          editor.setSelectedBufferRange([[6, 6], [6, 8]], autoscroll: true)
-          expect(editor.getScrollBottom()).toBe (7 + editor.getVerticalScrollMargin()) * 10
-          expect(editor.getScrollRight()).toBe (8 + editor.getHorizontalScrollMargin()) * 10
+        editor.setSelectedBufferRange([[0, 0], [0, 0]])
+        expect(editor.getScrollTop()).toBe 0
+        expect(editor.getScrollLeft()).toBe 0
+
+        editor.setSelectedBufferRange([[6, 6], [6, 8]])
+        expect(editor.getScrollBottom()).toBe (7 + editor.getVerticalScrollMargin()) * 10
+        expect(editor.getScrollRight()).toBe (8 + editor.getHorizontalScrollMargin()) * 10

    describe ".selectMarker(marker)", ->
      describe "if the marker is valid", ->
@@ -1560,16 +1593,15 @@ describe "TextEditor", ->
        expect(editor.getSelectedBufferRanges()).toEqual [[[0, 0], [0, 0]], [[3, 4], [5, 6]]]

      it "autoscrolls to the added selection if needed", ->
-        editor.manageScrollPosition = true
-
+        editor.setVerticalScrollMargin(2)
+        editor.setHorizontalScrollMargin(2)
        editor.setLineHeightInPixels(10)
        editor.setDefaultCharWidth(10)
-        editor.setHeight(50)
-        editor.setWidth(50)
-
+        editor.setHeight(80)
+        editor.setWidth(100)
        editor.addSelectionForBufferRange([[8, 10], [8, 15]])
-        expect(editor.getScrollTop()).toBe 75
-        expect(editor.getScrollLeft()).toBe 160
+        expect(editor.getScrollBottom()).toBe (9 * 10) + (2 * 10)
+        expect(editor.getScrollRight()).toBe (15 * 10) + (2 * 10)

    describe ".addSelectionBelow()", ->
      describe "when the selection is non-empty", ->
@@ -1922,7 +1954,6 @@ describe "TextEditor", ->
            expect(cursor2.getBufferPosition()).toEqual [2, 7]

          it "autoscrolls to the last cursor", ->
-            editor.manageScrollPosition = true
            editor.setCursorScreenPosition([1, 2])
            editor.addCursorAtScreenPosition([10, 4])
            editor.setLineHeightInPixels(10)
@@ -4056,7 +4087,7 @@ describe "TextEditor", ->
      editor.setLineHeightInPixels(10)
      editor.setDefaultCharWidth(10)
      editor.setHeight(60)
-      editor.setWidth(50)
+      editor.setWidth(130)
      editor.setHorizontalScrollbarHeight(0)
      expect(editor.getScrollTop()).toBe 0
      expect(editor.getScrollLeft()).toBe 0
@@ -4072,8 +4103,6 @@ describe "TextEditor", ->

  describe ".pageUp/Down()", ->
    it "scrolls one screen height up or down and moves the cursor one page length", ->
-      editor.manageScrollPosition = true
-
      editor.setLineHeightInPixels(10)
      editor.setHeight(50)
      expect(editor.getScrollHeight()).toBe 130
@@ -4097,8 +4126,6 @@ describe "TextEditor", ->

  describe ".selectPageUp/Down()", ->
    it "selects one screen height of text up or down", ->
-      editor.manageScrollPosition = true
-
      editor.setLineHeightInPixels(10)
      editor.setHeight(50)
      expect(editor.getScrollHeight()).toBe 130
--- a/spec/typescript-spec.coffee
+++ b/spec/typescript-spec.coffee
@@ -0,0 +1,30 @@
+typescript = require '../src/typescript'
+crypto = require 'crypto'
+
+describe "TypeScript transpiler support", ->
+  describe "::createTypeScriptVersionAndOptionsDigest", ->
+    it "returns a digest for the library version and specified options", ->
+      defaultOptions =
+        target: 1 # ES5
+        module: 'commonjs'
+        sourceMap: true
+      version = '1.4.1'
+      shasum = crypto.createHash('sha1')
+      shasum.update('typescript', 'utf8')
+      shasum.update('\0', 'utf8')
+      shasum.update(version, 'utf8')
+      shasum.update('\0', 'utf8')
+      shasum.update(JSON.stringify(defaultOptions))
+      expectedDigest = shasum.digest('hex')
+
+      observedDigest = typescript.createTypeScriptVersionAndOptionsDigest(version, defaultOptions)
+      expect(observedDigest).toEqual expectedDigest
+
+  describe "when there is a .ts file", ->
+    it "transpiles it using typescript", ->
+      transpiled = require('./fixtures/typescript/valid.ts')
+      expect(transpiled(3)).toBe 4
+
+  describe "when the .ts file is invalid", ->
+    it "does not transpile", ->
+      expect(-> require('./fixtures/typescript/invalid.ts')).toThrow()
--- a/src/compile-cache.coffee
+++ b/src/compile-cache.coffee
@@ -2,6 +2,7 @@ path = require 'path'
 CSON = require 'season'
 CoffeeCache = require 'coffee-cash'
 babel = require './babel'
+typescript = require './typescript'

 # This file is required directly by apm so that files can be cached during
 # package install so that the first package load in Atom doesn't have to
@@ -16,6 +17,7 @@ exports.addPathToCache = (filePath, atomHome) ->
  CoffeeCache.setCacheDirectory(path.join(cacheDir, 'coffee'))
  CSON.setCacheDir(path.join(cacheDir, 'cson'))
  babel.setCacheDirectory(path.join(cacheDir, 'js', 'babel'))
+  typescript.setCacheDirectory(path.join(cacheDir, 'ts'))

  switch path.extname(filePath)
    when '.coffee'
@@ -24,3 +26,5 @@ exports.addPathToCache = (filePath, atomHome) ->
      CSON.readFileSync(filePath)
    when '.js'
      babel.addPathToCache(filePath)
+    when '.ts'
+      typescript.addPathToCache(filePath)
--- a/src/cursor.coffee
+++ b/src/cursor.coffee
@@ -15,7 +15,6 @@ class Cursor extends Model
  bufferPosition: null
  goalColumn: null
  visible: true
-  needsAutoscroll: null

  # Instantiated by a {TextEditor}
  constructor: ({@editor, @marker, id}) ->
@@ -30,10 +29,6 @@ class Cursor extends Model
      {textChanged} = e
      return if oldHeadScreenPosition.isEqual(newHeadScreenPosition)

-      # Supports old editor view
-      @needsAutoscroll ?= @isLastCursor() and !textChanged
-      @autoscroll() if @editor.manageScrollPosition and @isLastCursor() and textChanged
-
      @goalColumn = null

      movedEvent =
@@ -53,7 +48,6 @@ class Cursor extends Model
      @emit 'destroyed'
      @emitter.emit 'did-destroy'
      @emitter.dispose()
-    @needsAutoscroll = true

  destroy: ->
    @marker.destroy()
@@ -128,8 +122,9 @@ class Cursor extends Model
  #
  # * `bufferPosition` {Array} of two numbers: the buffer row, and the buffer column.
  # * `options` (optional) {Object} with the following keys:
-  #   * `autoscroll` A Boolean which, if `true`, scrolls the {TextEditor} to wherever
-  #     the cursor moves to.
+  #   * `autoscroll` {Boolean} indicating whether to autoscroll to the new
+  #     position. Defaults to `true` if this is the most recently added cursor,
+  #     `false` otherwise.
  setBufferPosition: (bufferPosition, options={}) ->
    @changePosition options, =>
      @marker.setHeadBufferPosition(bufferPosition, options)
@@ -600,7 +595,6 @@ class Cursor extends Model
  setVisible: (visible) ->
    if @visible != visible
      @visible = visible
-      @needsAutoscroll ?= true if @visible and @isLastCursor()
      @emit 'visibility-changed', @visible
      @emitter.emit 'did-change-visibility', @visible

@@ -628,11 +622,10 @@ class Cursor extends Model

  # Public: Prevents this cursor from causing scrolling.
  clearAutoscroll: ->
-    @needsAutoscroll = null

  # Public: Deselects the current selection.
-  clearSelection: ->
-    @selection?.clear()
+  clearSelection: (options) ->
+    @selection?.clear(options)

  # Public: Get the RegExp used by the cursor to determine what a "word" is.
  #
@@ -655,12 +648,9 @@ class Cursor extends Model
  ###

  changePosition: (options, fn) ->
-    @clearSelection()
-    @needsAutoscroll = options.autoscroll ? @isLastCursor()
+    @clearSelection(options)
    fn()
-    if @needsAutoscroll
-      @emit 'autoscrolled' # Support legacy editor
-      @autoscroll() if @needsAutoscroll and @editor.manageScrollPosition # Support react editor view
+    @autoscroll() if options.autoscroll ? @isLastCursor()

  getPixelRect: ->
    @editor.pixelRectForScreenRange(@getScreenRange())
--- a/src/display-buffer.coffee
+++ b/src/display-buffer.coffee
@@ -22,7 +22,6 @@ class DisplayBuffer extends Model
  Serializable.includeInto(this)

  @properties
-    manageScrollPosition: false
    softWrapped: null
    editorWidthInChars: null
    lineHeightInPixels: null
@@ -200,12 +199,22 @@ class DisplayBuffer extends Model
  # visible - A {Boolean} indicating of the tokenized buffer is shown
  setVisible: (visible) -> @tokenizedBuffer.setVisible(visible)

-  getVerticalScrollMargin: -> @verticalScrollMargin
+  getVerticalScrollMargin: -> Math.min(@verticalScrollMargin, (@getHeight() - @getLineHeightInPixels()) / 2)
  setVerticalScrollMargin: (@verticalScrollMargin) -> @verticalScrollMargin

-  getHorizontalScrollMargin: -> @horizontalScrollMargin
+  getVerticalScrollMarginInPixels: ->
+    scrollMarginInPixels = @getVerticalScrollMargin() * @getLineHeightInPixels()
+    maxScrollMarginInPixels = (@getHeight() - @getLineHeightInPixels()) / 2
+    Math.min(scrollMarginInPixels, maxScrollMarginInPixels)
+
+  getHorizontalScrollMargin: -> Math.min(@horizontalScrollMargin, (@getWidth() - @getDefaultCharWidth()) / 2)
  setHorizontalScrollMargin: (@horizontalScrollMargin) -> @horizontalScrollMargin

+  getHorizontalScrollMarginInPixels: ->
+    scrollMarginInPixels = @getHorizontalScrollMargin() * @getDefaultCharWidth()
+    maxScrollMarginInPixels = (@getWidth() - @getDefaultCharWidth()) / 2
+    Math.min(scrollMarginInPixels, maxScrollMarginInPixels)
+
  getHorizontalScrollbarHeight: -> @horizontalScrollbarHeight
  setHorizontalScrollbarHeight: (@horizontalScrollbarHeight) -> @horizontalScrollbarHeight

@@ -268,26 +277,19 @@ class DisplayBuffer extends Model

  getScrollTop: -> @scrollTop
  setScrollTop: (scrollTop) ->
-    if @manageScrollPosition
-      @scrollTop = Math.round(Math.max(0, Math.min(@getMaxScrollTop(), scrollTop)))
-    else
-      @scrollTop = Math.round(scrollTop)
+    @scrollTop = Math.round(Math.max(0, Math.min(@getMaxScrollTop(), scrollTop)))

  getMaxScrollTop: ->
    @getScrollHeight() - @getClientHeight()

-  getScrollBottom: -> @scrollTop + @height
+  getScrollBottom: -> @scrollTop + @getClientHeight()
  setScrollBottom: (scrollBottom) ->
    @setScrollTop(scrollBottom - @getClientHeight())
    @getScrollBottom()

  getScrollLeft: -> @scrollLeft
  setScrollLeft: (scrollLeft) ->
-    if @manageScrollPosition
-      @scrollLeft = Math.round(Math.max(0, Math.min(@getScrollWidth() - @getClientWidth(), scrollLeft)))
-      @scrollLeft
-    else
-      @scrollLeft = Math.round(scrollLeft)
+    @scrollLeft = Math.round(Math.max(0, Math.min(@getScrollWidth() - @getClientWidth(), scrollLeft)))

  getMaxScrollLeft: ->
    @getScrollWidth() - @getClientWidth()
@@ -372,15 +374,16 @@ class DisplayBuffer extends Model
    @intersectsVisibleRowRange(start.row, end.row + 1)

  scrollToScreenRange: (screenRange, options) ->
-    verticalScrollMarginInPixels = @getVerticalScrollMargin() * @getLineHeightInPixels()
-    horizontalScrollMarginInPixels = @getHorizontalScrollMargin() * @getDefaultCharWidth()
+    verticalScrollMarginInPixels = @getVerticalScrollMarginInPixels()
+    horizontalScrollMarginInPixels = @getHorizontalScrollMarginInPixels()

-    {top, left, height, width} = @pixelRectForScreenRange(screenRange)
-    bottom = top + height
-    right = left + width
+    {top, left} = @pixelRectForScreenRange(new Range(screenRange.start, screenRange.start))
+    {top: endTop, left: endLeft, height: endHeight} = @pixelRectForScreenRange(new Range(screenRange.end, screenRange.end))
+    bottom = endTop + endHeight
+    right = endLeft

    if options?.center
-      desiredScrollCenter = top + height / 2
+      desiredScrollCenter = (top + bottom) / 2
      unless @getScrollTop() < desiredScrollCenter < @getScrollBottom()
        desiredScrollTop =  desiredScrollCenter - @getHeight() / 2
        desiredScrollBottom =  desiredScrollCenter + @getHeight() / 2
@@ -391,15 +394,26 @@ class DisplayBuffer extends Model
    desiredScrollLeft = left - horizontalScrollMarginInPixels
    desiredScrollRight = right + horizontalScrollMarginInPixels

-    if desiredScrollTop < @getScrollTop()
-      @setScrollTop(desiredScrollTop)
-    else if desiredScrollBottom > @getScrollBottom()
-      @setScrollBottom(desiredScrollBottom)
+    if options?.reversed ? true
+      if desiredScrollBottom > @getScrollBottom()
+        @setScrollBottom(desiredScrollBottom)
+      if desiredScrollTop < @getScrollTop()
+        @setScrollTop(desiredScrollTop)

-    if desiredScrollLeft < @getScrollLeft()
-      @setScrollLeft(desiredScrollLeft)
-    else if desiredScrollRight > @getScrollRight()
-      @setScrollRight(desiredScrollRight)
+      if desiredScrollRight > @getScrollRight()
+        @setScrollRight(desiredScrollRight)
+      if desiredScrollLeft < @getScrollLeft()
+        @setScrollLeft(desiredScrollLeft)
+    else
+      if desiredScrollTop < @getScrollTop()
+        @setScrollTop(desiredScrollTop)
+      if desiredScrollBottom > @getScrollBottom()
+        @setScrollBottom(desiredScrollBottom)
+
+      if desiredScrollLeft < @getScrollLeft()
+        @setScrollLeft(desiredScrollLeft)
+      if desiredScrollRight > @getScrollRight()
+        @setScrollRight(desiredScrollRight)

  scrollToScreenPosition: (screenPosition, options) ->
    @scrollToScreenRange(new Range(screenPosition, screenPosition), options)
@@ -1113,7 +1127,7 @@ class DisplayBuffer extends Model
  handleTokenizedBufferChange: (tokenizedBufferChange) =>
    {start, end, delta, bufferChange} = tokenizedBufferChange
    @updateScreenLines(start, end + 1, delta, delayChangeEvent: bufferChange?)
-    @setScrollTop(Math.min(@getScrollTop(), @getMaxScrollTop())) if @manageScrollPosition and delta < 0
+    @setScrollTop(Math.min(@getScrollTop(), @getMaxScrollTop())) if delta < 0

  updateScreenLines: (startBufferRow, endBufferRow, bufferDelta=0, options={}) ->
    startBufferRow = @rowMap.bufferRowRangeForBufferRow(startBufferRow)[0]
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -686,7 +686,7 @@ class Pane extends Model
    true

  handleSaveError: (error) ->
-    if error.message.endsWith('is a directory')
+    if error.code is 'EISDIR' or error.message.endsWith('is a directory')
      atom.notifications.addWarning("Unable to save file: #{error.message}")
    else if error.code is 'EACCES' and error.path?
      atom.notifications.addWarning("Unable to save file: Permission denied '#{error.path}'")
--- a/src/selection.coffee
+++ b/src/selection.coffee
@@ -1,6 +1,6 @@
 {Point, Range} = require 'text-buffer'
 {Model} = require 'theorist'
-{pick} = require 'underscore-plus'
+{pick} = _ = require 'underscore-plus'
 {Emitter} = require 'event-kit'
 Grim = require 'grim'

@@ -14,7 +14,6 @@ class Selection extends Model
  editor: null
  initialScreenRange: null
  wordwise: false
-  needsAutoscroll: null

  constructor: ({@cursor, @marker, @editor, id}) ->
    @emitter = new Emitter
@@ -35,6 +34,9 @@ class Selection extends Model
  destroy: ->
    @marker.destroy()

+  isLastSelection: ->
+    this is @editor.getLastSelection()
+
  ###
  Section: Event Subscription
  ###
@@ -96,19 +98,20 @@ class Selection extends Model
  #
  # * `screenRange` The new {Range} to select.
  # * `options` (optional) {Object} with the keys:
-  #   * `preserveFolds` if `true`, the fold settings are preserved after the selection moves.
-  #   * `autoscroll` if `true`, the {TextEditor} scrolls to the new selection.
+  #   * `preserveFolds` if `true`, the fold settings are preserved after the
+  #     selection moves.
+  #   * `autoscroll` {Boolean} indicating whether to autoscroll to the new
+  #     range. Defaults to `true` if this is the most recently added selection,
+  #     `false` otherwise.
  setBufferRange: (bufferRange, options={}) ->
    bufferRange = Range.fromObject(bufferRange)
-    @needsAutoscroll = options.autoscroll
    options.reversed ?= @isReversed()
    @editor.destroyFoldsContainingBufferRange(bufferRange) unless options.preserveFolds
    @modifySelection =>
      needsFlash = options.flash
      delete options.flash if options.flash?
-      @cursor.needsAutoscroll = false if @needsAutoscroll?
      @marker.setBufferRange(bufferRange, options)
-      @autoscroll() if @needsAutoscroll and @editor.manageScrollPosition
+      @autoscroll() if options?.autoscroll ? @isLastSelection()
      @decoration.flash('flash', @editor.selectionFlashDuration) if needsFlash

  # Public: Returns the starting and ending buffer rows the selection is
@@ -184,9 +187,15 @@ class Selection extends Model
  ###

  # Public: Clears the selection, moving the marker to the head.
-  clear: ->
+  #
+  # * `options` (optional) {Object} with the following keys:
+  #   * `autoscroll` {Boolean} indicating whether to autoscroll to the new
+  #     range. Defaults to `true` if this is the most recently added selection,
+  #     `false` otherwise.
+  clear: (options) ->
    @marker.setProperties(goalScreenRange: null)
    @marker.clearTail() unless @retainSelection
+    @autoscroll() if options?.autoscroll ? @isLastSelection()
    @finalize()

  # Public: Selects the text from the current cursor position to a given screen
@@ -359,7 +368,6 @@ class Selection extends Model
    @editor.unfoldBufferRow(oldBufferRange.end.row)
    wasReversed = @isReversed()
    @clear()
-    @cursor.needsAutoscroll = @cursor.isLastCursor()

    autoIndentFirstLine = false
    precedingText = @editor.getTextInRange([[oldBufferRange.start.row, 0], oldBufferRange.start])
@@ -398,6 +406,8 @@ class Selection extends Model
    else if options.autoDecreaseIndent and NonWhitespaceRegExp.test(text)
      @editor.autoDecreaseIndentForBufferRow(newBufferRange.start.row)

+    @autoscroll() if @isLastSelection()
+
    newBufferRange

  # Public: Removes the first character before the selection if the selection
@@ -713,7 +723,7 @@ class Selection extends Model
    else
      options.goalScreenRange = myGoalScreenRange ? otherGoalScreenRange

-    @setBufferRange(@getBufferRange().union(otherSelection.getBufferRange()), options)
+    @setBufferRange(@getBufferRange().union(otherSelection.getBufferRange()), _.extend(autoscroll: false, options))
    otherSelection.destroy()

  ###
@@ -755,10 +765,12 @@ class Selection extends Model
      @linewise = false

  autoscroll: ->
-    @editor.scrollToScreenRange(@getScreenRange())
+    if @marker.hasTail()
+      @editor.scrollToScreenRange(@getScreenRange(), reversed: @isReversed())
+    else
+      @cursor.autoscroll()

  clearAutoscroll: ->
-    @needsAutoscroll = null

  modifySelection: (fn) ->
    @retainSelection = true
--- a/src/text-editor-component.coffee
+++ b/src/text-editor-component.coffee
@@ -39,7 +39,6 @@ class TextEditorComponent
    @lineOverdrawMargin = lineOverdrawMargin if lineOverdrawMargin?
    @disposables = new CompositeDisposable

-    @editor.manageScrollPosition = true
    @observeConfig()
    @setScrollSensitivity(atom.config.get('editor.scrollSensitivity'))

--- a/src/text-editor.coffee
+++ b/src/text-editor.coffee
@@ -76,7 +76,7 @@ class TextEditor extends Model

  @delegatesProperties '$lineHeightInPixels', '$defaultCharWidth', '$height', '$width',
    '$verticalScrollbarWidth', '$horizontalScrollbarHeight', '$scrollTop', '$scrollLeft',
-    'manageScrollPosition', toProperty: 'displayBuffer'
+    toProperty: 'displayBuffer'

  constructor: ({@softTabs, initialLine, initialColumn, tabLength, softWrapped, @displayBuffer, buffer, registerEditor, suppressCursorCreation, @mini, @placeholderText, @gutterVisible}) ->
    super
@@ -1132,13 +1132,13 @@ class TextEditor extends Model

  # Essential: Undo the last change.
  undo: ->
-    @getLastCursor().needsAutoscroll = true
-    @buffer.undo(this)
+    @buffer.undo()
+    @getLastSelection().autoscroll()

  # Essential: Redo the last change.
  redo: ->
-    @getLastCursor().needsAutoscroll = true
    @buffer.redo(this)
+    @getLastSelection().autoscroll()

  # Extended: Batch multiple operations as a single undo/redo step.
  #
@@ -1608,8 +1608,9 @@ class TextEditor extends Model
  # * `bufferPosition` A {Point} or {Array} of `[row, column]`
  #
  # Returns a {Cursor}.
-  addCursorAtBufferPosition: (bufferPosition) ->
+  addCursorAtBufferPosition: (bufferPosition, options) ->
    @markBufferPosition(bufferPosition, @getSelectionMarkerAttributes())
+    @getLastSelection().cursor.autoscroll() unless options?.autoscroll is false
    @getLastSelection().cursor

  # Essential: Add a cursor at the position in screen coordinates.
@@ -1617,8 +1618,9 @@ class TextEditor extends Model
  # * `screenPosition` A {Point} or {Array} of `[row, column]`
  #
  # Returns a {Cursor}.
-  addCursorAtScreenPosition: (screenPosition) ->
+  addCursorAtScreenPosition: (screenPosition, options) ->
    @markScreenPosition(screenPosition, @getSelectionMarkerAttributes())
+    @getLastSelection().cursor.autoscroll() unless options?.autoscroll is false
    @getLastSelection().cursor

  # Essential: Returns {Boolean} indicating whether or not there are multiple cursors.
@@ -1949,9 +1951,8 @@ class TextEditor extends Model
  # Returns the added {Selection}.
  addSelectionForBufferRange: (bufferRange, options={}) ->
    @markBufferRange(bufferRange, _.defaults(@getSelectionMarkerAttributes(), options))
-    selection = @getLastSelection()
-    selection.autoscroll() if @manageScrollPosition
-    selection
+    @getLastSelection().autoscroll() unless options.autoscroll is false
+    @getLastSelection()

  # Essential: Add a selection for the given range in screen coordinates.
  #
@@ -1963,9 +1964,8 @@ class TextEditor extends Model
  # Returns the added {Selection}.
  addSelectionForScreenRange: (screenRange, options={}) ->
    @markScreenRange(screenRange, _.defaults(@getSelectionMarkerAttributes(), options))
-    selection = @getLastSelection()
-    selection.autoscroll() if @manageScrollPosition
-    selection
+    @getLastSelection().autoscroll() unless options.autoscroll is false
+    @getLastSelection()

  # Essential: Select from the current cursor position to the given position in
  # buffer coordinates.
@@ -2271,6 +2271,7 @@ class TextEditor extends Model
    @selections.push(selection)
    selectionBufferRange = selection.getBufferRange()
    @mergeIntersectingSelections(preserveFolds: marker.getProperties().preserveFolds)
+
    if selection.destroyed
      for selection in @getSelections()
        if selection.intersectsBufferRange(selectionBufferRange)
@@ -2288,9 +2289,9 @@ class TextEditor extends Model

  # Reduce one or more selections to a single empty selection based on the most
  # recently added cursor.
-  clearSelections: ->
+  clearSelections: (options) ->
    @consolidateSelections()
-    @getLastSelection().clear()
+    @getLastSelection().clear(options)

  # Reduce multiple selections to the most recently added selection.
  consolidateSelections: ->
--- a/src/typescript.coffee
+++ b/src/typescript.coffee
@@ -0,0 +1,106 @@
+###
+Cache for source code transpiled by TypeScript.
+
+Inspired by https://github.com/atom/atom/blob/7a719d585db96ff7d2977db9067e1d9d4d0adf1a/src/babel.coffee
+###
+
+crypto = require 'crypto'
+fs = require 'fs-plus'
+path = require 'path'
+tss = null # Defer until used
+
+stats =
+  hits: 0
+  misses: 0
+
+defaultOptions =
+  target: 1 # ES5
+  module: 'commonjs'
+  sourceMap: true
+
+createTypeScriptVersionAndOptionsDigest = (version, options) ->
+  shasum = crypto.createHash('sha1')
+  # Include the version of typescript in the hash.
+  shasum.update('typescript', 'utf8')
+  shasum.update('\0', 'utf8')
+  shasum.update(version, 'utf8')
+  shasum.update('\0', 'utf8')
+  shasum.update(JSON.stringify(options))
+  shasum.digest('hex')
+
+cacheDir = null
+jsCacheDir = null
+
+getCachePath = (sourceCode) ->
+  digest = crypto.createHash('sha1').update(sourceCode, 'utf8').digest('hex')
+
+  unless jsCacheDir?
+    tssVersion = require('typescript-simple/package.json').version
+    jsCacheDir = path.join(cacheDir, createTypeScriptVersionAndOptionsDigest(tssVersion, defaultOptions))
+
+  path.join(jsCacheDir, "#{digest}.js")
+
+getCachedJavaScript = (cachePath) ->
+  if fs.isFileSync(cachePath)
+    try
+      cachedJavaScript = fs.readFileSync(cachePath, 'utf8')
+      stats.hits++
+      return cachedJavaScript
+  null
+
+# Returns the TypeScript options that should be used to transpile filePath.
+createOptions = (filePath) ->
+  options = filename: filePath
+  for key, value of defaultOptions
+    options[key] = value
+  options
+
+transpile = (sourceCode, filePath, cachePath) ->
+  options = createOptions(filePath)
+  unless tss?
+    {TypeScriptSimple} = require 'typescript-simple'
+    tss = new TypeScriptSimple(options, false)
+  js = tss.compile(sourceCode, filePath)
+  stats.misses++
+
+  try
+    fs.writeFileSync(cachePath, js)
+
+  js
+
+# Function that obeys the contract of an entry in the require.extensions map.
+# Returns the transpiled version of the JavaScript code at filePath, which is
+# either generated on the fly or pulled from cache.
+loadFile = (module, filePath) ->
+  sourceCode = fs.readFileSync(filePath, 'utf8')
+  cachePath = getCachePath(sourceCode)
+  js = getCachedJavaScript(cachePath) ? transpile(sourceCode, filePath, cachePath)
+  module._compile(js, filePath)
+
+register = ->
+  Object.defineProperty(require.extensions, '.ts', {
+    enumerable: true
+    writable: false
+    value: loadFile
+  })
+
+setCacheDirectory = (newCacheDir) ->
+  if cacheDir isnt newCacheDir
+    cacheDir = newCacheDir
+    jsCacheDir = null
+
+module.exports =
+  register: register
+  setCacheDirectory: setCacheDirectory
+  getCacheMisses: -> stats.misses
+  getCacheHits: -> stats.hits
+
+  # Visible for testing.
+  createTypeScriptVersionAndOptionsDigest: createTypeScriptVersionAndOptionsDigest
+
+  addPathToCache: (filePath) ->
+    return if path.extname(filePath) isnt '.ts'
+
+    sourceCode = fs.readFileSync(filePath, 'utf8')
+    cachePath = getCachePath(sourceCode)
+    transpile(sourceCode, filePath, cachePath)
--- a/static/index.js
+++ b/static/index.js
@@ -47,6 +47,7 @@ window.onload = function() {
    setupCsonCache(cacheDir);
    setupSourceMapCache(cacheDir);
    setupBabel(cacheDir);
+    setupTypeScript(cacheDir);

    require(loadSettings.bootstrapScript);
    require('ipc').sendChannel('window-command', 'window:loaded');
@@ -95,6 +96,12 @@ var setupBabel = function(cacheDir) {
  babel.register();
 }

+var setupTypeScript = function(cacheDir) {
+  var typescript = require('../src/typescript');
+  typescript.setCacheDirectory(path.join(cacheDir, 'typescript'));
+  typescript.register();
+}
+
 var setupCsonCache = function(cacheDir) {
  require('season').setCacheDir(path.join(cacheDir, 'cson'));
 }