Own tildify function that leaves path alone if not in home

package.json

@@ -33,7 +33,6 @@
     "async": "~0.2.9",
     "mkdirp": "~0.3.5",
     "rimraf": "~2.2.2",
-    "tildify": "^1.2.0",
     "underscore-plus": "1.x"
   }
 }

spec/fs-plus-spec.coffee

@@ -503,19 +503,74 @@ describe "fs", ->
       expect(fs.normalize('~/foo')).toBe path.join(fs.getHomeDirectory(), 'foo')
 
   describe ".tildify(pathToTildify)", ->
-    it "tildifys the path", ->
+    originalPlatform = null
+    originalHome = null
+    originalSep = null
+    originalNormalize = null
+
+    beforeEach ->
+      originalPlatform = process.platform
+      originalHome = process.env.HOME
+      originalSep = path.sep
+      originalNormalize = path.normalize
+      # path.js changes per platform, mocking the above doesn't help with this function
+      Object.defineProperty path, 'normalize', value: (path) -> originalNormalize(path).replace(/\\/g, '/')
+
+    afterEach ->
+      Object.defineProperty process, 'platform', value: originalPlatform
+      Object.defineProperty process.env, 'HOME', value: originalHome
+      Object.defineProperty path, 'sep', value: originalSep
+      Object.defineProperty path, 'normalize', value: originalNormalize
+
+    it "tildifys the path on macOS", ->
+      Object.defineProperty process, 'platform', value: 'darwin'
+      Object.defineProperty process.env, 'HOME', value: '/Users/Buzz'
+      Object.defineProperty path, 'sep', value: '/'
+
       home = fs.getHomeDirectory()
-      if process.platform is 'win32'
-        expect(fs.tildify(home)).toBe home
-      else
-        expect(fs.tildify(home)).toBe '~'
-        expect(fs.tildify(path.join(home, 'foo'))).toBe '~/foo'
-        fixture = path.join('foo', fs.getHomeDirectory())
-        expect(fs.tildify(fixture)).toBe fixture
-        fixture = path.resolve("#{home}foo", 'tildify')
-        expect(fs.tildify(fixture)).toBe fixture
-        expect(fs.tildify('foo')).toBe 'foo'
+      debugger
+      expect(fs.tildify(home)).toBe '~'
+      expect(fs.tildify(path.join(home, 'foo'))).toBe '~/foo'
+      fixture = path.join('foo', home)
+      expect(fs.tildify(fixture)).toBe fixture
+      fixture = path.resolve("#{home}foo", 'tildify')
+      expect(fs.tildify(fixture)).toBe fixture
+      expect(fs.tildify('foo')).toBe 'foo'
+
+    it "tildifys the path on Linux", ->
+      Object.defineProperty process, 'platform', value: 'linux'
+      Object.defineProperty process.env, 'HOME', value: '/home/buzz'
+      Object.defineProperty path, 'sep', value: '/'
+
+      home = fs.getHomeDirectory()
+      expect(fs.tildify(home)).toBe '~'
+      expect(fs.tildify(path.join(home, 'foo'))).toBe '~/foo'
+      fixture = path.join('foo', home)
+      expect(fs.tildify(fixture)).toBe fixture
+      fixture = path.resolve("#{home}foo", 'tildify')
+      expect(fs.tildify(fixture)).toBe fixture
+      expect(fs.tildify('foo')).toBe 'foo'
+
+    it "doesn't tildify the path on Windows", ->
+      Object.defineProperty process, 'platform', value: 'win32'
+      Object.defineProperty process.env, 'USERPROFILE', value: 'C:\\Users\\Buzz'
+      Object.defineProperty path, 'sep', value: '\\'
+
+      home = fs.getHomeDirectory()
+
+      expect(fs.tildify(home)).toBe home
+      expect(fs.tildify(path.join(home, 'foo'))).toBe path.join(home, 'foo')
+
+    it "doesn't change URLs or paths not tildified", ->
+      Object.defineProperty process, 'platform', value: 'darwin'
+      Object.defineProperty process.env, 'HOME', value: '/Users/Buzz'
+      Object.defineProperty path, 'sep', value: '/'
+
+      urlToLeaveAlone = "https://atom.io/something/fun?abc"
+      expect(fs.tildify(urlToLeaveAlone)).toBe urlToLeaveAlone
 
+      pathToLeaveAlone = "/Library/Support/Atom/State"
+      expect(fs.tildify(pathToLeaveAlone)).toBe pathToLeaveAlone
 
   describe ".move", ->
     tempDir = null

src/fs-plus.coffee

@@ -4,7 +4,6 @@ path = require 'path'
 
 _ = require 'underscore-plus'
 async = require 'async'
-tildify = require 'tildify'
 mkdirp = require 'mkdirp'
 rimraf = require 'rimraf'
 
@@ -61,15 +60,22 @@ fsPlus =
       return "#{fsPlus.getHomeDirectory()}#{relativePath.substring(1)}"
     return relativePath
 
-  # Public: Convert an absolute path to tilde path for linux and mac:
+  # Public: Convert an absolute path to tilde path for Linux and macOS.
   # /Users/username/dev => ~/dev
   #
   # pathToTildify - The {String} containing the full path.
   #
   # Returns a tildified path {String}.
   tildify: (pathToTildify) ->
     return pathToTildify if process.platform is 'win32'
-    return tildify(pathToTildify)
+
+    normalized = fsPlus.normalize(pathToTildify)
+    homeDir = fsPlus.getHomeDirectory()
+
+    return '~' if normalized is homeDir
+    return pathToTildify unless normalized.startsWith(path.join(homeDir, path.sep))
+
+    path.join('~', path.sep, normalized.substring(homeDir.length + 1))
 
   # Public: Get path to store application specific data.
   #