Fix help render when NO_COLOR is specified

Currently, running `--help` with `NO_COLOR` set, results in formatting still being applied via markup to the options and default values.

This complements the previous fix for spectreconsole#211 for that scenario and is related to spectreconsole#1408.

Fixes spectreconsole#1583

src/Spectre.Console.Cli/Internal/Composer.cs

@@ -9,6 +9,11 @@ internal sealed class Composer : IRenderable
  /// </summary>
  private readonly bool _renderMarkup = false;
 
+ /// <summary>
+ /// Whether to avoid all styling in the output.
+ /// </summary>
+ private readonly bool _noColor = Environment.GetEnvironmentVariables().Contains("NO_COLOR");
+
  public Composer()
  {
  _content = new StringBuilder();
@@ -22,12 +27,24 @@ public Composer(bool renderMarkup)
 
  public Composer Text(string text)
  {
+ if (_noColor && !string.IsNullOrWhiteSpace(text))
+ {
+ _content.Append(text.RemoveMarkup());
+ return this;
+ }
+
  _content.Append(text);
  return this;
  }
 
  public Composer Style(Style style, string text)
  {
+ if (_noColor)
+ {
+ _content.Append(text.EscapeMarkup());
+ return this;
+ }
+
  _content.Append('[').Append(style.ToMarkup()).Append(']');
  _content.Append(text.EscapeMarkup());
  _content.Append("[/]");
@@ -37,6 +54,12 @@ public Composer Style(Style style, string text)
 
  public Composer Style(string style, string text)
  {
+ if (_noColor)
+ {
+ _content.Append(text.EscapeMarkup());
+ return this;
+ }
+
  _content.Append('[').Append(style).Append(']');
  _content.Append(text.EscapeMarkup());
  _content.Append("[/]");
@@ -46,6 +69,12 @@ public Composer Style(string style, string text)
 
  public Composer Style(string style, Action<Composer> action)
  {
+ if (_noColor)
+ {
+ action(this);
+ return this;
+ }
+
  _content.Append('[').Append(style).Append(']');
  action(this);
  _content.Append("[/]");
@@ -114,7 +143,7 @@ public Composer Join(string separator, IEnumerable<Composer> composers)
 
  public Measurement Measure(RenderOptions options, int maxWidth)
  {
- if (_renderMarkup)
+ if (_renderMarkup || _noColor)
  {
  return ((IRenderable)new Paragraph(_content.ToString())).Measure(options, maxWidth);
  }
@@ -126,7 +155,7 @@ public Measurement Measure(RenderOptions options, int maxWidth)
 
  public IEnumerable<Segment> Render(RenderOptions options, int maxWidth)
  {
- if (_renderMarkup)
+ if (_renderMarkup || _noColor)
  {
  return ((IRenderable)new Paragraph(_content.ToString())).Render(options, maxWidth);
  }