1 files changed, 54 insertions, 0 deletions
diff --git a/cli/internal/ui/colors.go b/cli/internal/ui/colors.go
new file mode 100644
index 0000000..4b2eccd
--- /dev/null
+++ b/cli/internal/ui/colors.go
@@ -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 forceColor := os.Getenv("FORCE_COLOR"); {
+	case forceColor == "false" || forceColor == "0":
+		return ColorModeSuppressed
+	case forceColor == "true" || forceColor == "1" || forceColor == "2" || forceColor == "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
+	}
+}