Fix: now highlights in diff view are getting the correct lines.

models/git_diff.go

@@ -77,28 +77,24 @@ func diffToHtml(diffRecord []diffmatchpatch.Diff, lineType DiffLineType) templat
 	return template.HTML(result)
 }
 
-func (diffSection *DiffSection) GetLeftLine(idx int, sliceIdx int) *DiffLine {
-	for i, diffLine := range diffSection.Lines {
-		if diffLine.LeftIdx == idx && diffLine.RightIdx == 0 {
-			// ignore if the lines are too far from each other
-			if i > sliceIdx-5 && i < sliceIdx+5 {
-				return diffLine
-			} else {
-				return nil
-			}
+// get an specific line by type (add or del) and file line number
+func (diffSection *DiffSection) GetLine(lineType DiffLineType, idx int) *DiffLine {
+	difference := 0
+
+	for _, diffLine := range diffSection.Lines {
+		if diffLine.Type == DIFF_LINE_PLAIN {
+			// get the difference of line numbers between ADD and DEL versions
+			difference = diffLine.RightIdx - diffLine.LeftIdx
+			continue
 		}
-	}
-	return nil
-}
 
-func (diffSection *DiffSection) GetRightLine(idx int, sliceIdx int) *DiffLine {
-	for i, diffLine := range diffSection.Lines {
-		if diffLine.RightIdx == idx && diffLine.LeftIdx == 0 {
-			// ignore if the lines are too far from each other
-			if i > sliceIdx-5 && i < sliceIdx+5 {
+		if lineType == DIFF_LINE_DEL {
+			if diffLine.RightIdx == 0 && diffLine.LeftIdx == idx - difference {
+				return diffLine
+			}
+		} else if lineType == DIFF_LINE_ADD {
+			if diffLine.LeftIdx == 0 && diffLine.RightIdx == idx + difference {
 				return diffLine
-			} else {
-				return nil
 			}
 		}
 	}
@@ -107,7 +103,7 @@ func (diffSection *DiffSection) GetRightLine(idx int, sliceIdx int) *DiffLine {
 
 // computes diff of each diff line and set the HTML on diffLine.ParsedContent
 func (diffSection *DiffSection) ComputeLinesDiff() {
-	for i, diffLine := range diffSection.Lines {
+	for _, diffLine := range diffSection.Lines {
 		var compareDiffLine *DiffLine
 		var diff1, diff2 string
 
@@ -121,14 +117,14 @@ func (diffSection *DiffSection) ComputeLinesDiff() {
 
 		// try to find equivalent diff line. ignore, otherwise
 		if diffLine.Type == DIFF_LINE_ADD {
-			compareDiffLine = diffSection.GetLeftLine(diffLine.RightIdx, i)
+			compareDiffLine = diffSection.GetLine(DIFF_LINE_DEL, diffLine.RightIdx)
 			if compareDiffLine == nil {
 				continue
 			}
 			diff1 = compareDiffLine.Content
 			diff2 = diffLine.Content
 		} else {
-			compareDiffLine = diffSection.GetRightLine(diffLine.LeftIdx, i)
+			compareDiffLine = diffSection.GetLine(DIFF_LINE_ADD, diffLine.LeftIdx)
 			if compareDiffLine == nil {
 				continue
 			}

models/git_diff_test.go

@@ -12,6 +12,12 @@ func assertEqual(t *testing.T, s1 string, s2 template.HTML) {
   }
 }
 
+func assertLineEqual(t *testing.T, d1 *DiffLine, d2 *DiffLine) {
+  if d1 != d2 {
+    t.Errorf("%v should be equal %v", d1, d2)
+  }
+}
+
 func TestDiffToHtml(t *testing.T) {
   assertEqual(t, "foo <span class=\"added-code\">bar</span> biz", diffToHtml([]dmp.Diff{
     dmp.Diff{dmp.DiffEqual, "foo "},
@@ -27,3 +33,38 @@ func TestDiffToHtml(t *testing.T) {
     dmp.Diff{dmp.DiffEqual, " biz"},
   }, DIFF_LINE_DEL))
 }
+
+// test if GetLine is return the correct lines
+func TestGetLine(t *testing.T) {
+  ds := DiffSection{Lines: []*DiffLine{
+    &DiffLine{LeftIdx: 28,  RightIdx:   28, Type: DIFF_LINE_PLAIN},
+    &DiffLine{LeftIdx: 29,  RightIdx:   29, Type: DIFF_LINE_PLAIN},
+    &DiffLine{LeftIdx: 30,  RightIdx:   30, Type: DIFF_LINE_PLAIN},
+    &DiffLine{LeftIdx: 31,  RightIdx:    0, Type: DIFF_LINE_DEL},
+    &DiffLine{LeftIdx:  0,  RightIdx:   31, Type: DIFF_LINE_ADD},
+    &DiffLine{LeftIdx:  0,  RightIdx:   32, Type: DIFF_LINE_ADD},
+    &DiffLine{LeftIdx: 32,  RightIdx:   33, Type: DIFF_LINE_PLAIN},
+    &DiffLine{LeftIdx: 33,  RightIdx:    0, Type: DIFF_LINE_DEL},
+    &DiffLine{LeftIdx: 34,  RightIdx:    0, Type: DIFF_LINE_DEL},
+    &DiffLine{LeftIdx: 35,  RightIdx:    0, Type: DIFF_LINE_DEL},
+    &DiffLine{LeftIdx: 36,  RightIdx:    0, Type: DIFF_LINE_DEL},
+    &DiffLine{LeftIdx:  0,  RightIdx:   34, Type: DIFF_LINE_ADD},
+    &DiffLine{LeftIdx:  0,  RightIdx:   35, Type: DIFF_LINE_ADD},
+    &DiffLine{LeftIdx:  0,  RightIdx:   36, Type: DIFF_LINE_ADD},
+    &DiffLine{LeftIdx:  0,  RightIdx:   37, Type: DIFF_LINE_ADD},
+    &DiffLine{LeftIdx: 37,  RightIdx:   38, Type: DIFF_LINE_PLAIN},
+    &DiffLine{LeftIdx: 38,  RightIdx:   39, Type: DIFF_LINE_PLAIN},
+  }}
+
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_ADD, 31), ds.Lines[4])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_DEL, 31), ds.Lines[3])
+
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_ADD, 33), ds.Lines[11])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_ADD, 34), ds.Lines[12])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_ADD, 35), ds.Lines[13])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_ADD, 36), ds.Lines[14])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_DEL, 34), ds.Lines[7])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_DEL, 35), ds.Lines[8])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_DEL, 36), ds.Lines[9])
+  assertLineEqual(t, ds.GetLine(DIFF_LINE_DEL, 37), ds.Lines[10])
+}