colorwriter

README

colorwriter Package

Thin wrapper that returns a color-profile-aware io.Writer for terminal output, with a no-op stub for wasm builds.

Overview

The colorwriter package provides a factory for io.Writer values that adapt ANSI color output based on the current environment. On non-wasm platforms it wraps the given writer with github.com/charmbracelet/colorprofile so that NO_COLOR, COLORTERM, and terminal capability are consulted automatically. On wasm (js / wasm build tags) the package returns the writer unchanged, since color-profile detection is not supported on that platform.

It is imported by pkg/console and pkg/logger to obtain a consistent stderr writer.

Public API

Symbol	Signature	Description
New	func(w io.Writer, environ []string) io.Writer	Returns a color-profile-aware writer wrapping w using environ (e.g. os.Environ()) to detect NO_COLOR, COLORTERM, and terminal capabilities. On wasm, returns w unchanged.
Stderr	func() io.Writer	Convenience wrapper that calls New(os.Stderr, os.Environ()). On wasm, returns os.Stderr directly.

Build variants

Build constraint	Behavior
!js && !wasm (colorprofile_writer.go)	New delegates to colorprofile.NewWriter; Stderr wraps os.Stderr with the process environment.
js || wasm (colorprofile_writer_wasm.go)	New returns w unchanged; Stderr returns os.Stderr directly. Color-profile detection is not supported on wasm.

Usage Examples

import (
    "os"

    "github.com/github/gh-aw/pkg/colorwriter"
)

// Wrap an arbitrary writer (e.g. for tests or piped output).
w := colorwriter.New(os.Stderr, os.Environ())
fmt.Fprintln(w, "styled output respects NO_COLOR and terminal capabilities")

// Obtain a ready-to-use stderr writer.
stderr := colorwriter.Stderr()
fmt.Fprintln(stderr, "styled output to os.Stderr")

Dependencies

External:

• github.com/charmbracelet/colorprofile — color-profile detection and ANSI downgrading (non-wasm builds only)

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This specification is automatically maintained by the spec-extractor workflow.

Documentation

Index

• func New(w io.Writer, environ []string) io.Writer
• func Stderr() io.Writer

Functions

func New

func New(w io.Writer, environ []string) io.Writer

New returns an io.Writer that adapts color output based on the provided environment variables (e.g. NO_COLOR, COLORTERM, TERM).

func Stderr

func Stderr() io.Writer

Stderr returns a color-profile-aware writer for os.Stderr using the current process environment.