Clear rightmost screen position when resetting a display layer

Author: Antonio Scandurra

spec/display-layer-spec.js

@@ -54,16 +54,24 @@ describe('DisplayLayer', () => {
 
   describe('reset()', () => {
     it('updates the screen lines to reflect the new parameters', () => {
-      const buffer = new TextBuffer({
-        text: 'abc def\nghi jkl\nmno pqr'
-      })
-
+      const buffer = new TextBuffer({text: 'abc def\nghi jkl\nmno pqr'})
       const displayLayer = buffer.addDisplayLayer({})
       expect(displayLayer.translateScreenPosition(Point(1, 3))).toEqual(Point(1, 3))
 
       displayLayer.reset({softWrapColumn: 4})
       expect(displayLayer.translateScreenPosition(Point(1, 3))).toEqual(Point(0, 7))
     })
+
+    it('resets the rightmost screen position', () => {
+      const buffer = new TextBuffer({text: 'abc def\nghi jkl\nmnopqrst'})
+      const displayLayer = buffer.addDisplayLayer({softWrapColumn: 5})
+      expect(displayLayer.getApproximateRightmostScreenPosition()).toEqual(Point(0, 0))
+      expect(displayLayer.getRightmostScreenPosition()).toEqual(Point(4, 5))
+
+      displayLayer.reset({softWrapColumn: 4})
+      expect(displayLayer.getApproximateRightmostScreenPosition()).toEqual(Point(0, 0))
+      expect(displayLayer.getRightmostScreenPosition()).toEqual(Point(0, 4))
+    })
   })
 
   describe('destroy', function () {

src/display-layer.js

@@ -128,6 +128,7 @@ class DisplayLayer {
     this.cachedScreenLines.length = 0
     this.screenLineLengths.length = 0
     this.tabCounts.length = 0
+    this.rightmostScreenPosition = Point(0, 0)
   }
 
   doBackgroundWork (deadline) {