feat: simplify color system - remove automatic detection

Remove complex color detection heuristics in favor of simple boolean control.
This gives users complete control over when colors are used.

Changes:
- Remove NO_COLOR environment variable detection
- Remove TTY detection and automatic color logic
- Colors now only work when color: true is explicitly set
- Update documentation to reflect simplified behavior
- Update tests to match new behavior
- Update examples to show simple boolean control

Benefits:
- Predictable behavior - no environment surprises
- Simpler API - just a boolean flag
- User control - users can implement their own detection wrapper
- Lighter weight - less environment dependencies

Breaking change:
- Previously colors might auto-enable based on TTY/environment
- Now colors only work when explicitly enabled with color: true
- Users who want automatic detection should wrap their CLI logic

Author: sigmaSd

README.md

@@ -334,8 +334,7 @@ properties.
   - `name?: string` - The name of the application (shown in help)
   - `description?: string` - A brief description of the application (shown in
     help)
-  - `color?: boolean` - Enable colored help output (respects NO_COLOR
-    environment variable)
+  - `color?: boolean` - Enable colored help output (no automatic detection)
   - `showDefaults?: boolean` - Show default values in help text (default: true)
   - `defaultCommand?: string | "help"` - Default command to run when no
     arguments are provided
@@ -1069,7 +1068,7 @@ Options:
 
 ### Colored Help Output
 
-Enable colored help text that respects the NO_COLOR environment variable standard:
+Enable colored help text with simple boolean control:
 
 ```typescript
 @parse(Deno.args, {
@@ -1087,20 +1086,17 @@ class Config {
 ```
 
 **Color behavior:**
-- Colors are automatically disabled if `NO_COLOR` environment variable is set
-- Colors are disabled if stdout is not a TTY (e.g., piped output)
-- Use `color: true` to request colors (still respects NO_COLOR and TTY)
-- Use `color: false` to explicitly disable colors
+- Use `color: true` to enable colored output
+- Use `color: false` or omit the option to disable colors
+- No automatic detection based on environment variables or TTY
+- Users can implement their own color detection wrapper if needed
 
 ```bash
-# Colored help (if terminal supports it)
+# Colored help (when color: true is set)
 deno run app.ts --help
 
-# Disable colors via environment variable
-NO_COLOR=1 deno run app.ts --help
-
-# Disable colors via pipe
-deno run app.ts --help | cat
+# Plain help (default behavior)
+deno run app.ts --help
 ```
 
 ### Show Default Values

examples/new_features.ts

@@ -1,6 +1,6 @@
 /**
  * Demonstration of new CLI parsing features:
- * - Colored help output with NO_COLOR support
+ * - Colored help output with simple boolean control
  * - Default values shown in help text
  * - Default command functionality
  */
@@ -69,7 +69,7 @@ class TestCommand {
 @parse(Deno.args, {
   name: "devtool",
   description: "A modern development tool with colored help and smart defaults",
-  color: true, // Enable colored output (respects NO_COLOR)
+  color: true, // Enable colored output
   showDefaults: true, // Show default values in help
   defaultCommand: "help", // Show help when no command is provided
 })
@@ -147,14 +147,11 @@ deno run new_features.ts build src/main.ts --minify --output build
 # Verbose mode
 deno run new_features.ts --verbose serve
 
-# Disable colors
-NO_COLOR=1 deno run new_features.ts
-
 # Help for specific command
 deno run new_features.ts serve --help
 
 Features demonstrated:
-- ✅ Colored help output (respects NO_COLOR env var)
+- ✅ Colored help output (simple boolean control)
 - ✅ Default values shown in help text
 - ✅ Default command (shows help when no args provided)
 - ✅ Nested subcommands with proper help

src/colors.ts

@@ -1,13 +1,12 @@
 /**
  * Color utilities for CLI help output with NO_COLOR environment variable support.
  *
- * This module provides ANSI color codes for terminal output while respecting
- * the NO_COLOR environment variable standard (https://no-color.org/).
+ * This module provides ANSI color codes for terminal output.
  *
  * Features:
- * - Automatic color detection based on environment
- * - NO_COLOR environment variable support
- * - Graceful fallback to plain text
+ * - Simple boolean-based color control
+ * - No automatic detection or environment checks
+ * - Users can implement their own color detection logic
  * - Common color functions for CLI output
  */
 
@@ -50,37 +49,14 @@ const COLORS = {
 /**
  * Determines if color output should be enabled.
  *
- * Colors are disabled if:
- * - NO_COLOR environment variable is set (any value)
- * - Terminal doesn't support colors
- * - Color is explicitly disabled
+ * Simply returns the enableColor value - no heuristics or environment checks.
+ * Users can wrap their CLI with their own color detection logic if needed.
  *
  * @param enableColor - Explicit color preference
  * @returns true if colors should be used
  */
 function shouldUseColors(enableColor?: boolean): boolean {
-  // Explicit disable takes precedence
-  if (enableColor === false) {
-    return false;
-  }
-
-  // Check NO_COLOR environment variable
-  if (process.env.NO_COLOR !== undefined) {
-    return false;
-  }
-
-  // Check if stdout is a TTY
-  if (!process.stdout.isTTY) {
-    return false;
-  }
-
-  // If explicitly enabled, use colors
-  if (enableColor === true) {
-    return true;
-  }
-
-  // Default: auto-detect based on environment
-  return process.stdout.isTTY && !process.env.NO_COLOR;
+  return enableColor === true;
 }
 
 /**
@@ -155,6 +131,6 @@ export function createColors(enableColor?: boolean): {
 }
 
 /**
- * Default color instance for convenience.
+ * Default color instance for convenience (colors disabled by default).
  */
 export const colors = createColors();

src/types.ts

@@ -151,7 +151,7 @@ export interface ParseOptions {
   name?: string;
   /** Application description shown in help text */
   description?: string;
-  /** Enable colored help output (respects NO_COLOR environment variable) */
+  /** Enable colored help output (no automatic detection) */
   color?: boolean;
   /** Show default values in help text */
   showDefaults?: boolean;

tests/lib.test.ts

@@ -1795,46 +1795,31 @@ Deno.test("Color support - help output with colors enabled", () => {
   }
 });
 
-Deno.test("Color support - respects NO_COLOR environment variable", () => {
-  // Save original environment
-  const originalNoColor = Deno.env.get("NO_COLOR");
+Deno.test("Color support - disabled when color option is false", () => {
+  mockProcessExit();
 
   try {
-    // Set NO_COLOR environment variable
-    Deno.env.set("NO_COLOR", "1");
-
-    mockProcessExit();
-
-    try {
-      const output = captureConsoleOutput(() => {
-        try {
-          @parse(["--help"], {
-            name: "nocolor",
-            description: "Test NO_COLOR",
-            color: true, // Even with color=true, NO_COLOR should disable it
-          })
-          class _Config {
-            static port: number = 8080;
-          }
-        } catch (_e) {
-          // Expected process.exit call
+    const output = captureConsoleOutput(() => {
+      try {
+        @parse(["--help"], {
+          name: "nocolor",
+          description: "Test color disabled",
+          color: false,
+        })
+        class _NoColorTest {
+          static port: number = 8080;
         }
-      });
-
-      assertEquals(exitCode, 0);
-      // Colors should NOT be present in output when NO_COLOR is set
-      assertEquals(output.includes("\x1b["), false);
-      assertEquals(output.includes("nocolor"), true);
-    } finally {
-      restoreProcessExit();
-    }
+      } catch (_e) {
+        // Expected process.exit call
+      }
+    });
+
+    assertEquals(exitCode, 0);
+    // Colors should NOT be present in output when color=false
+    assertEquals(output.includes("\x1b["), false);
+    assertEquals(output.includes("nocolor"), true);
   } finally {
-    // Restore original environment
-    if (originalNoColor !== undefined) {
-      Deno.env.set("NO_COLOR", originalNoColor);
-    } else {
-      Deno.env.delete("NO_COLOR");
-    }
+    restoreProcessExit();
   }
 });