Add support for NO_COLOR environment variable

This overrides adding the `colorOption` argument to the restart command
line if the NO_COLOR environment variable exists and no specific color
argument has been provided. See: https://no-color.org/

Author: johnstevenson

src/Process.php

@@ -50,6 +50,11 @@ public static function addColorOption(array $args, $colorOption)
             return $args;
         }
 
+        // Check for NO_COLOR variable (https://no-color.org/)
+        if (false !== getenv('NO_COLOR')) {
+            return $args;
+        }
+
         if (false !== ($index = array_search('--', $args))) {
             // Position option before double-dash delimiter
             array_splice($args, $index, 0, $colorOption);

tests/ColourOptionTest.php

@@ -18,6 +18,33 @@
  */
 class ColorOptionTest extends TestCase
 {
+    private static $nocolor;
+
+    /**
+     * Saves the NO_COLOR environment variable
+     */
+    public static function setUpBeforeClass()
+    {
+        self::$nocolor = getenv('NO_COLOR');
+    }
+
+    /**
+     * Restores the original NO_COLOR environment variable
+     */
+    public static function tearDownAfterClass()
+    {
+        $value = false !== self::$nocolor ? '='.self::$nocolor : '';
+        putenv('NO_COLOR'.$value);
+    }
+
+    /**
+     * Unsets the NO_COLOR environment variable for each test
+     */
+    protected function setUp()
+    {
+        putenv('NO_COLOR');
+    }
+
     /**
      * Tests that a colorOption is added to the arguments
      *
@@ -29,6 +56,18 @@ public function testOptionNeeded($args, $colorOption, $expected)
         $this->assertSame($expected, implode(' ', $result));
     }
 
+    /**
+     * Tests that a colorOption is not added if NO_COLOR is set
+     *
+     * @dataProvider neededProvider
+     */
+    public function testOptionNeededNoColor($args, $colorOption, $unused)
+    {
+        putenv('NO_COLOR=1');
+        $result = Process::addColorOption($args, $colorOption);
+        $this->assertSame($args, $result);
+    }
+
     public function neededProvider()
     {
         // $args, $colorOption, $expected