add 'sprintf' vs. 'printf' | add simple coloring test

colors.go

@@ -8,20 +8,35 @@ import (
 
 type terminalColor uint32
 
-var colorMap = make(map[string]terminalColor)
+type Theme map[string]terminalColor
+
+var theme Theme = make(map[string]terminalColor)
 
 func init() {
-	colorMap["red"] = 0xff0000
+	theme["black"] = 0x000000
-	colorMap["green"] = 0x00ff00
+	theme["white"] = 0xffffff
-	colorMap["blue"] = 0x0000ff
+	theme["red"] = 0xff0000
+	theme["green"] = 0x00ff00
+	theme["blue"] = 0x0000ff
+	theme["yellow"] = 0xffff00
+	theme["orange"] = 0xff8c00
+	theme["purple"] = 0x800080
+	theme["navy"] = 0x000080
+	theme["aqua"] = 0x00ffff
+	theme["gray"] = 0x808080
+	theme["silver"] = 0xc0c0c0
+	theme["fuchsia"] = 0xff00ff
+	theme["olive"] = 0x808000
+	theme["teal"] = 0x008080
+	theme["brown"] = 0x800000
 }
 
 // fromName returns the integer value of a color name
 // from the built-in color map ; it is case insensitive
 func fromName(s string) (terminalColor, error) {
-	value, ok := colorMap[s]
+	value, ok := theme[s]
 	if !ok {
-		return 0, fmt.Errorf("unknown color name '%'", s)
+		return 0, fmt.Errorf("unknown color name '%s'", s)
 	}
 	return value, nil
 }

printer.go

@@ -16,7 +16,8 @@ import (
 // - [Format] -> ${Text}(:Color)      # background color only
 var extractor = regexp.MustCompile(`(?m)\${([^$]+)}\(((?:[a-z]+|#(?:[0-9a-f]{3}|[0-9a-f]{6})))?(?:\:((?:[a-z]+|#(?:[0-9a-f]{3}|[0-9a-f]{6}))))?\)`)
 
-func Printf(format string, a ...interface{}) error {
+// Sprintf returns a terminal-colorized output following the coloring format
+func Sprintf(format string, a ...interface{}) (string, error) {
 	// 1. Pre-process format with 'fmt'
 	input := fmt.Sprintf(format, a...)
 	output := ""
@@ -45,14 +46,14 @@ func Printf(format string, a ...interface{}) error {
 			sForeground = input[match[4]:match[5]]
 			foreground, err = parseColor(sForeground)
 			if err != nil {
-				return err
+				return "", err
 			}
 		}
 		if match[7]-match[6] > 0 {
 			sBackground = input[match[6]:match[7]]
 			background, err = parseColor(sBackground)
 			if err != nil {
-				return err
+				return "", err
 			}
 		}
 
@@ -72,7 +73,16 @@ func Printf(format string, a ...interface{}) error {
 	}
 
 	// 3. print final output
-	fmt.Print(output)
+	return output, nil
+}
+
+func Printf(format string, a ...interface{}) error {
+	s, err := Sprintf(format, a...)
+	if err != nil {
+		return err
+	}
+
+	fmt.Print(s)
 	return nil
 }
 

printer_test.go

@@ -0,0 +1,85 @@
+package clifmt
+
+import (
+	"testing"
+)
+
+func TestColoring(t *testing.T) {
+
+	tests := []struct {
+		Input  string
+		Output string
+	}{
+		// foreground + background
+		{
+			"start ${some text input}(#ff0000:#00ff00) end\n",
+			"start \033[48;2;0;255;0m\033[38;2;255;0;0msome text input\033[0m\033[0m end\n",
+		}, {
+			"start ${some text input}(#f00:#0f0) end\n",
+			"start \033[48;2;0;255;0m\033[38;2;255;0;0msome text input\033[0m\033[0m end\n",
+		}, {
+			"start ${some text input}(red:green) end\n",
+			"start \033[48;2;0;255;0m\033[38;2;255;0;0msome text input\033[0m\033[0m end\n",
+		},
+
+		// mixed notations
+		{
+			"start ${some text input}(red:#00ff00) end\n",
+			"start \033[48;2;0;255;0m\033[38;2;255;0;0msome text input\033[0m\033[0m end\n",
+		}, {
+			"start ${some text input}(red:#0f0) end\n",
+			"start \033[48;2;0;255;0m\033[38;2;255;0;0msome text input\033[0m\033[0m end\n",
+		}, {
+			"start ${some text input}(#ff0000:green) end\n",
+			"start \033[48;2;0;255;0m\033[38;2;255;0;0msome text input\033[0m\033[0m end\n",
+		}, {
+			"start ${some text input}(#f00:green) end\n",
+			"start \033[48;2;0;255;0m\033[38;2;255;0;0msome text input\033[0m\033[0m end\n",
+		},
+
+		// foreground only
+		{
+			"start ${some text input}(red) end\n",
+			"start \033[38;2;255;0;0msome text input\033[0m end\n",
+		}, {
+			"start ${some text input}(#ff0000) end\n",
+			"start \033[38;2;255;0;0msome text input\033[0m end\n",
+		}, {
+			"start ${some text input}(#f00) end\n",
+			"start \033[38;2;255;0;0msome text input\033[0m end\n",
+		},
+
+		// background only
+		{
+			"start ${some text input}(:blue) end\n",
+			"start \033[48;2;0;0;255msome text input\033[0m end\n",
+		}, {
+			"start ${some text input}(:#0000ff) end\n",
+			"start \033[48;2;0;0;255msome text input\033[0m end\n",
+		}, {
+			"start ${some text input}(:#00f) end\n",
+			"start \033[48;2;0;0;255msome text input\033[0m end\n",
+		},
+
+		// multi matches
+		{
+			"start ${text1}(red) separation ${text2}(#0f0) end\n",
+			"start \033[38;2;255;0;0mtext1\033[0m separation \033[38;2;0;255;0mtext2\033[0m end\n",
+		}, {
+			"start ${text1}(:red) separation ${text2}(:#0f0) end\n",
+			"start \033[48;2;255;0;0mtext1\033[0m separation \033[48;2;0;255;0mtext2\033[0m end\n",
+		}}
+
+	for i, test := range tests {
+		output, err := Sprintf(test.Input)
+		if err != nil {
+			t.Errorf("[%d] unexpected error <%v>", i, err)
+			break
+		}
+
+		if output != test.Output {
+			t.Errorf("[%d] expected '%s', got '%s'", i, test.Output, output)
+		}
+
+	}
+}