Merge pull request #294 from atom/aw/has-astral

TextBuffer::hasAstral()

Author: smashwilson

package-lock.json

@@ -54,7 +54,7 @@
     "mkdirp": "^0.5.1",
     "pathwatcher": "8.0.1",
     "serializable": "^1.0.3",
-    "superstring": "^2.2.20",
+    "superstring": "2.3.0",
     "underscore-plus": "^1.0.0"
   },
   "standard": {

package.json

@@ -2609,6 +2609,13 @@ describe "TextBuffer", ->
       buffer.setText('\n')
       expect(buffer.isEmpty()).toBeFalsy()
 
+  describe "::hasAstral()", ->
+    it "returns true for buffers containing surrogate pairs", ->
+      expect(new TextBuffer('hooray 😄').hasAstral()).toBeTruthy()
+
+    it "returns false for buffers that do not contain surrogate pairs", ->
+      expect(new TextBuffer('nope').hasAstral()).toBeFalsy()
+
   describe "::onWillChange(callback)", ->
     it "notifies observers before a transaction, an undo or a redo", ->
       changeCount = 0

spec/text-buffer-spec.coffee

@@ -170,6 +170,7 @@ class TextBuffer
     @nextMarkerId = 1
     @outstandingSaveCount = 0
     @loadCount = 0
+    @cachedHasAstral = null
     @_emittedWillChangeEvent = false
 
     @setEncoding(params?.encoding)
@@ -728,6 +729,17 @@ class TextBuffer
         return row unless @isRowBlank(row)
     null
 
+  # Extended: Return true if the buffer contains any astral-plane Unicode characters that
+  # are encoded as surrogate pairs.
+  #
+  # Returns a {Boolean}.
+  hasAstral: ->
+    if @cachedHasAstral isnt null
+      @cachedHasAstral
+    else
+      @cachedHasAstral = @buffer.hasAstral()
+      @cachedHasAstral
+
   ###
   Section: Mutating Text
   ###
@@ -2066,6 +2078,7 @@ class TextBuffer
       @_emittedWillChangeEvent = true
 
   emitDidChangeTextEvent: ->
+    @cachedHasAstral = null
     if @transactCallDepth is 0
       if @changesSinceLastDidChangeTextEvent.length > 0
         compactedChanges = patchFromChanges(@changesSinceLastDidChangeTextEvent).getChanges()