plumbing: diff, fix coloring of hunk context

2 files changed, 51 insertions, 15 deletions

diff --git a/plumbing/format/diff/unified_encoder.go b/plumbing/format/diff/unified_encoder.go
index 7b0c31e..6472db2 100644
--- a/plumbing/format/diff/unified_encoder.go
+++ b/plumbing/format/diff/unified_encoder.go
@@ -15,7 +15,7 @@ const (
 
 	chunkStart  = "@@ -"
 	chunkMiddle = " +"
-	chunkEnd    = " @@%s\n"
+	chunkEnd    = " @@"
 	chunkCount  = "%d,%d"
 
 	noFilePath = "/dev/null"
@@ -230,7 +230,7 @@ func (c *hunksGenerator) processHunk(i int, op Operation) {
 	var ctxPrefix string
 	linesBefore := len(c.beforeContext)
 	if linesBefore > c.ctxLines {
-		ctxPrefix = " " + c.beforeContext[linesBefore-c.ctxLines-1]
+		ctxPrefix = c.beforeContext[linesBefore-c.ctxLines-1]
 		c.beforeContext = c.beforeContext[linesBefore-c.ctxLines:]
 		linesBefore = c.ctxLines
 	}
@@ -337,9 +337,18 @@ func (c *hunk) WriteTo(buf *bytes.Buffer, color ColorConfig) {
 		fmt.Fprintf(buf, chunkCount, c.toLine, c.toCount)
 	}
 
-	fmt.Fprintf(buf, chunkEnd, c.ctxPrefix)
+	buf.WriteString(chunkEnd)
 	buf.WriteString(color.Reset())
 
+	if c.ctxPrefix != "" {
+		buf.WriteByte(' ')
+		buf.WriteString(color[Func])
+		buf.WriteString(c.ctxPrefix)
+		buf.WriteString(color.Reset())
+	}
+
+	buf.WriteByte('\n')
+
 	for _, d := range c.ops {
 		buf.WriteString(d.String(color))
 	}
diff --git a/plumbing/format/diff/unified_encoder_test.go b/plumbing/format/diff/unified_encoder_test.go
index f72424a..6eaec72 100644
--- a/plumbing/format/diff/unified_encoder_test.go
+++ b/plumbing/format/diff/unified_encoder_test.go
@@ -894,12 +894,11 @@ index 0adddcde4fd38042c354518351820eb06c417c82..d39ae38aad7ba9447b5e7998b2e4714f
 		color.Bold + "diff --git a/README.md b/README.md\n" +
 		"index 94954abda49de8615a048f8d2e64b5de848e27a1..f3dad9514629b9ff9136283ae331ad1fc95748a8 100644\n" +
 		"--- a/README.md\n" +
-		"+++ b/README.md\n" +
-		color.Reset + color.Cyan + "@@ -1,2 +1,2 @@\n" +
-		color.Normal + color.Reset + " hello\n" +
-		color.Reset + color.Red + "-world\n" +
-		color.Reset + color.Green + "+bug\n" +
-		color.Reset,
+		"+++ b/README.md\n" + color.Reset +
+		color.Cyan + "@@ -1,2 +1,2 @@" + color.Reset + "\n" +
+		color.Normal + " hello\n" + color.Reset +
+		color.Red + "-world\n" + color.Reset +
+		color.Green + "+bug\n" + color.Reset,
 }, {
 	patch: testPatch{
 		message: "",
@@ -927,16 +926,44 @@ index 0adddcde4fd38042c354518351820eb06c417c82..d39ae38aad7ba9447b5e7998b2e4714f
 
 	desc:    "one line change with color",
 	context: 1,
-	color:   NewColorConfig(),
+	color: NewColorConfig(
+		WithColor(Func, color.Reverse),
+	),
 	diff: "" +
 		color.Bold + "diff --git a/test.txt b/test.txt\n" +
 		"index 9daeafb9864cf43055ae93beb0afd6c7d144bfa4..180cf8328022becee9aaa2577a8f84ea2b9f3827 100644\n" +
 		"--- a/test.txt\n" +
-		"+++ b/test.txt\n" +
-		color.Reset + color.Cyan + "@@ -1 +1 @@\n" +
-		color.Reset + color.Red + "-test\n" +
-		color.Reset + color.Green + "+test2\n" +
-		color.Reset,
+		"+++ b/test.txt\n" + color.Reset +
+		color.Cyan + "@@ -1 +1 @@" + color.Reset + "\n" +
+		color.Red + "-test\n" + color.Reset +
+		color.Green + "+test2\n" + color.Reset,
+}, {
+	patch:   oneChunkPatch,
+	desc:    "modified deleting lines file with context to 1 with color",
+	context: 1,
+	color: NewColorConfig(
+		WithColor(Func, color.Reverse),
+	),
+	diff: "" +
+		color.Bold + "diff --git a/onechunk.txt b/onechunk.txt\n" +
+		"index ab5eed5d4a2c33aeef67e0188ee79bed666bde6f..0adddcde4fd38042c354518351820eb06c417c82 100644\n" +
+		"--- a/onechunk.txt\n" +
+		"+++ b/onechunk.txt\n" + color.Reset +
+		color.Cyan + "@@ -1,2 +1 @@" + color.Reset + "\n" +
+		color.Red + "-A\n" + color.Reset +
+		color.Normal + " B\n" + color.Reset +
+		color.Cyan + "@@ -7,3 +6,2 @@" + color.Reset + " " + color.Reverse + "F" + color.Reset + "\n" +
+		color.Normal + " G\n" + color.Reset +
+		color.Red + "-H\n" + color.Reset +
+		color.Normal + " I\n" + color.Reset +
+		color.Cyan + "@@ -14,3 +12,2 @@" + color.Reset + " " + color.Reverse + "M" + color.Reset + "\n" +
+		color.Normal + " N\n" + color.Reset +
+		color.Red + "-Ñ\n" + color.Reset +
+		color.Normal + " O\n" + color.Reset +
+		color.Cyan + "@@ -21,3 +18,2 @@" + color.Reset + " " + color.Reverse + "S" + color.Reset + "\n" +
+		color.Normal + " T\n" + color.Reset +
+		color.Red + "-U\n" + color.Reset +
+		color.Normal + " V\n" + color.Reset,
 }}
 
 type testPatch struct {