vercel · gsoltis · Apr 6, 2022 · Apr 3, 2022 · Apr 5, 2022 · Apr 6, 2022
@@ -41,10 +41,10 @@ jobs:
         run: pnpm install
 
       - name: Build & Unit Test
-        run: pnpm turbo run test --scope=cli
+        run: pnpm turbo -- run test --scope=cli --color
 
       - name: Lint
-        run: pnpm turbo run lint --scope=cli
+        run: pnpm turbo -- run lint --scope=cli --color
 
       - name: E2E Tests
         run: |
@@ -143,4 +143,6 @@ jobs:
 
       - name: Check examples
         shell: bash
+        env:
+          FORCED_COLOR: true
         run: ./scripts/run-examples.sh
@@ -28,6 +28,7 @@ func main() {
 	traceFile := ""
 	cpuprofileFile := ""
 	argsEnd := 0
+	colorMode := uiPkg.GetColorModeFromEnv()
 	for _, arg := range args {
 		switch {
 		case strings.HasPrefix(arg, "--heap="):
@@ -36,6 +37,10 @@ func main() {
 			traceFile = arg[len("--trace="):]
 		case strings.HasPrefix(arg, "--cpuprofile="):
 			cpuprofileFile = arg[len("--cpuprofile="):]
+		case arg == "--color":
+			colorMode = ui.ColorModeForced
+		case arg == "--no-color":
+			colorMode = ui.ColorModeSuppressed
 		default:
 			// Strip any arguments that were handled above
 			args[argsEnd] = arg
@@ -44,10 +49,10 @@ func main() {
 	}
 	args = args[:argsEnd]
 
+	ui := ui.BuildColoredUi(colorMode);
 	c := cli.NewCLI("turbo", turboVersion)
 
 	util.InitPrintf()
-	ui := ui.Default()
 
 	c.Args = args
 	c.HelpWriter = os.Stdout

@@ -810,10 +810,10 @@ func replayLogs(logger hclog.Logger, prefixUi cli.Ui, runOptions *RunOptions, lo
 		if outputLogsMode == HashLogs {
 			//Writing to Stdout only the "cache hit, replaying output" line
 			scan.Scan()
-			prefixUi.Output(ui.StripAnsi(string(scan.Bytes())))
+			prefixUi.Output(string(scan.Bytes()))
 		} else {
 			for scan.Scan() {
-				prefixUi.Output(ui.StripAnsi(string(scan.Bytes()))) //Writing to Stdout
+				prefixUi.Output(string(scan.Bytes())) //Writing to Stdout
 			}
 		}
 	}

@@ -0,0 +1,54 @@
+package ui
+
+import (
+	"os"
+
+	"github.com/fatih/color"
+)
+
+type ColorMode int
+
+const (
+	ColorModeUndefined ColorMode = iota + 1
+	ColorModeSuppressed
+	ColorModeForced
+)
+
+func GetColorModeFromEnv() ColorMode {
+	// The FORCED_COLOR behavior and accepted values are taken from the supports-color NodeJS Package:
+	// The accepted values as documented are "0" to disable, and "1", "2", or "3" to force-enable color
+	// at the specified support level (1 = 16 colors, 2 = 256 colors, 3 = 16M colors).
+	// We don't currently use the level for anything specific, and just treat things as on and off.
+	//
+	// Note: while "false" and "true" aren't documented, the library coerces these values to 0 and 1
+	// respectively, so that behavior is reproduced here as well. 
+	// https://www.npmjs.com/package/supports-color
+
+	switch forcedColor := os.Getenv("FORCED_COLOR"); {
+	case forcedColor == "false" || forcedColor == "0":
+		return ColorModeSuppressed
+	case forcedColor == "true" || forcedColor == "1" || forcedColor == "2" || forcedColor == "3":
+		return ColorModeForced
+	default:
+		return ColorModeUndefined
+	}
+}
+
+func applyColorMode(colorMode ColorMode) ColorMode {
+	switch colorMode {
+	case ColorModeForced:
+		color.NoColor = false
+	case ColorModeSuppressed:
+		color.NoColor = true
+	case ColorModeUndefined:
+	default:
+		// color.NoColor already gets its default value based on
+		// isTTY and/or the presence of the NO_COLOR env variable.
+	}
+
+	if color.NoColor {
+		return ColorModeSuppressed;
+	} else {
+		return ColorModeForced;
+	}
+}
@@ -2,6 +2,7 @@ package ui
 
 import (
 	"fmt"
+	"io"
 	"math"
 	"os"
 	"regexp"
@@ -23,13 +24,6 @@ var WARNING_PREFIX = color.New(color.Bold, color.FgYellow, color.ReverseVideo).S
 
 var ansiRegex = regexp.MustCompile(ansiEscapeStr)
 
-func StripAnsi(str string) string {
-	if !IsTTY {
-		return ansiRegex.ReplaceAllString(str, "")
-	}
-	return str
-}
-
 // Dim prints out dimmed text
 func Dim(str string) string {
 	return gray.Sprint(str)
@@ -50,9 +44,6 @@ func rgb(i int) (int, int, int) {
 
 // Rainbow function returns a formated colorized string ready to print it to the shell/terminal
 func Rainbow(text string) string {
-	if !IsTTY {
-		return text
-	}
 	var rainbowStr []string
 	for index, value := range text {
 		r, g, b := rgb(index)
@@ -63,13 +54,48 @@ func Rainbow(text string) string {
 	return strings.Join(rainbowStr, "")
 }
 
+type stripAnsiWriter struct {
+	wrappedWriter io.Writer
+}
+
+func (into *stripAnsiWriter) Write(p []byte) (int, error) {
+	n, err := into.wrappedWriter.Write(ansiRegex.ReplaceAll(p, []byte{}))
+	if (err != nil) {
+		// The number of bytes returned here isn't directly related to the input bytes
+		// if ansi color codes were being stripped out, but we are counting on Stdout.Write
+		// not failing under typical operation as well.
+		return n, err
+	}
+
+	// Write must return a non-nil error if it returns n < len(p). Consequently, if the
+	// wrappedWrite.Write call succeeded we will return len(p) as the number of bytes
+	// written.
+	return len(p), nil
+}
+
 // Default returns the default colored ui
 func Default() *cli.ColoredUi {
+	return BuildColoredUi(ColorModeUndefined)
+}
+
+func BuildColoredUi(colorMode ColorMode) *cli.ColoredUi {
+	colorMode = applyColorMode(colorMode);
+
+	var outWriter, errWriter io.Writer
+
+	if colorMode == ColorModeSuppressed {
+		outWriter = &stripAnsiWriter{wrappedWriter: os.Stdout}
+		errWriter = &stripAnsiWriter{wrappedWriter: os.Stderr}
+	} else {
+		outWriter = os.Stdout
+		errWriter = os.Stderr
+	}
+
 	return &cli.ColoredUi{
 		Ui: &cli.BasicUi{
 			Reader:      os.Stdin,
-			Writer:      os.Stdout,
-			ErrorWriter: os.Stderr,
+			Writer:      outWriter,
+			ErrorWriter: errWriter,
 		},
 		OutputColor: cli.UiColorNone,
 		InfoColor:   cli.UiColorNone,

@@ -25,6 +25,46 @@ Boolean options can be enabled as follows:
 --<option>=false
 ```
 
+## Global Arguments
+
+The following flags apply to all commands.
+
+#### `--color`
+
+Forces the use of color even when the output stream is not considered to be a TTY terminal.
+This can be used to enable turbo's color output for CI runners such as Github Actions which
+have support for rendering color in their log output.
+
+```sh
+turbo run build --color
+```
+
+Alternatively, you can also enable color using the `FORCED_COLOR` environment variable (borrowed
+from the [supports-color nodejs package](https://www.npmjs.com/package/supports-color)). Going
+this route may also unlock some additional colored output from the actual tasks themselves if
+they use `supports-color` to determine whether or not to output with colored output.
+
+```sh
+declare -x FORCED_COLOR=1
+turbo run build
+```
+
+#### `--no-color`
+
+Suppresses the use of color in the output when running turbo in an interactive / TTY session.
+
+```sh
+turbo run build --no-color
+```
+
+Alternatively, you can also suppress color using the `FORCED_COLOR` environment variable (borrowed
+from the [supports-color nodejs package](https://www.npmjs.com/package/supports-color)).
+
+```sh
+declare -x FORCED_COLOR=0
+turbo run build
+```
+
 ## `turbo run <task>`
 
 Run NPM scripts across all packages in specified scope. Tasks must be specified in your `pipeline` configuration.