plumbing: diff, Add initial colored output support. Fixes #33.

1 files changed, 96 insertions, 0 deletions

diff --git a/plumbing/format/diff/colorconfig.go b/plumbing/format/diff/colorconfig.go
new file mode 100644
index 0000000..b7c32e6
--- /dev/null
+++ b/plumbing/format/diff/colorconfig.go
@@ -0,0 +1,96 @@
+package diff
+
+import "github.com/go-git/go-git/v5/internal/color"
+
+// A ColorKey is a key into a ColorConfig map and also equal to the key in the
+// diff.color subsection of the config. See
+// https://github.com/git/git/blob/v2.26.2/diff.c#L83-L106.
+type ColorKey string
+
+// ColorKeys.
+const (
+	Context                   ColorKey = "context"
+	Meta                      ColorKey = "meta"
+	Frag                      ColorKey = "frag"
+	Old                       ColorKey = "old"
+	New                       ColorKey = "new"
+	Commit                    ColorKey = "commit"
+	Whitespace                ColorKey = "whitespace"
+	Func                      ColorKey = "func"
+	OldMoved                  ColorKey = "oldMoved"
+	OldMovedAlternative       ColorKey = "oldMovedAlternative"
+	OldMovedDimmed            ColorKey = "oldMovedDimmed"
+	OldMovedAlternativeDimmed ColorKey = "oldMovedAlternativeDimmed"
+	NewMoved                  ColorKey = "newMoved"
+	NewMovedAlternative       ColorKey = "newMovedAlternative"
+	NewMovedDimmed            ColorKey = "newMovedDimmed"
+	NewMovedAlternativeDimmed ColorKey = "newMovedAlternativeDimmed"
+	ContextDimmed             ColorKey = "contextDimmed"
+	OldDimmed                 ColorKey = "oldDimmed"
+	NewDimmed                 ColorKey = "newDimmed"
+	ContextBold               ColorKey = "contextBold"
+	OldBold                   ColorKey = "oldBold"
+	NewBold                   ColorKey = "newBold"
+)
+
+// A ColorConfig is a color configuration. A nil or empty ColorConfig
+// corresponds to no color.
+type ColorConfig map[ColorKey]string
+
+// A ColorConfigOption sets an option on a ColorConfig.
+type ColorConfigOption func(ColorConfig)
+
+// WithColor sets the color for key.
+func WithColor(key ColorKey, color string) ColorConfigOption {
+	return func(cc ColorConfig) {
+		cc[key] = color
+	}
+}
+
+// defaultColorConfig is the default color configuration. See
+// https://github.com/git/git/blob/v2.26.2/diff.c#L57-L81.
+var defaultColorConfig = ColorConfig{
+	Context:                   color.Normal,
+	Meta:                      color.Bold,
+	Frag:                      color.Cyan,
+	Old:                       color.Red,
+	New:                       color.Green,
+	Commit:                    color.Yellow,
+	Whitespace:                color.BgRed,
+	Func:                      color.Normal,
+	OldMoved:                  color.BoldMagenta,
+	OldMovedAlternative:       color.BoldBlue,
+	OldMovedDimmed:            color.Faint,
+	OldMovedAlternativeDimmed: color.FaintItalic,
+	NewMoved:                  color.BoldCyan,
+	NewMovedAlternative:       color.BoldYellow,
+	NewMovedDimmed:            color.Faint,
+	NewMovedAlternativeDimmed: color.FaintItalic,
+	ContextDimmed:             color.Faint,
+	OldDimmed:                 color.FaintRed,
+	NewDimmed:                 color.FaintGreen,
+	ContextBold:               color.Bold,
+	OldBold:                   color.BoldRed,
+	NewBold:                   color.BoldGreen,
+}
+
+// NewColorConfig returns a new ColorConfig.
+func NewColorConfig(options ...ColorConfigOption) ColorConfig {
+	cc := make(ColorConfig)
+	for key, value := range defaultColorConfig {
+		cc[key] = value
+	}
+	for _, option := range options {
+		option(cc)
+	}
+	return cc
+}
+
+// Reset returns the ANSI escape sequence to reset a color set from cc. If cc is
+// nil or empty then no reset is needed so it returns the empty string.
+func (cc ColorConfig) Reset() string {
+	if len(cc) == 0 {
+		return ""
+	}
+	return color.Reset
+}