[VarDumper][PhpUnitBridge] Fix color detection

Author: nicolas-grekas

DeprecationErrorHandler.php

@@ -403,27 +403,58 @@ private static function hasColorSupport()
             return false;
         }
 
-        if ('Hyper' === getenv('TERM_PROGRAM')) {
+        if (!self::isTty()) {
             return true;
         }
 
-        if (\DIRECTORY_SEPARATOR === '\\') {
-            return (\function_exists('sapi_windows_vt100_support')
-                && sapi_windows_vt100_support(\STDOUT))
-                || false !== getenv('ANSICON')
-                || 'ON' === getenv('ConEmuANSI')
-                || 'xterm' === getenv('TERM');
+        if ('\\' === \DIRECTORY_SEPARATOR
+            && \function_exists('sapi_windows_vt100_support')
+            && @sapi_windows_vt100_support(\STDOUT)
+        ) {
+            return true;
         }
 
+        if ('Hyper' === getenv('TERM_PROGRAM')
+            || false !== getenv('COLORTERM')
+            || false !== getenv('ANSICON')
+            || 'ON' === getenv('ConEmuANSI')
+        ) {
+            return true;
+        }
+
+        if ('dumb' === $term = (string) getenv('TERM')) {
+            return false;
+        }
+
+        // See https://github.com/chalk/supports-color/blob/d4f413efaf8da045c5ab440ed418ef02dbb28bf1/index.js#L157
+        return preg_match('/^((screen|xterm|vt100|vt220|putty|rxvt|ansi|cygwin|linux).*)|(.*-256(color)?(-bce)?)$/', $term);
+    }
+
+    /**
+     * Checks if the stream is a TTY, i.e; whether the output stream is connected to a terminal.
+     *
+     * Reference: Composer\Util\Platform::isTty
+     * https://github.com/composer/composer
+     */
+    private static function isTty(): bool
+    {
+        // Detect msysgit/mingw and assume this is a tty because detection
+        // does not work correctly, see https://github.com/composer/composer/issues/9690
+        if (\in_array(strtoupper((string) getenv('MSYSTEM')), ['MINGW32', 'MINGW64'], true)) {
+            return true;
+        }
+
+        // Modern cross-platform function, includes the fstat fallback so if it is present we trust it
         if (\function_exists('stream_isatty')) {
             return @stream_isatty(\STDOUT);
         }
 
-        if (\function_exists('posix_isatty')) {
-            return @posix_isatty(\STDOUT);
+        // Only trusting this if it is positive, otherwise prefer fstat fallback.
+        if (\function_exists('posix_isatty') && @posix_isatty(\STDOUT)) {
+            return true;
         }
 
-        $stat = fstat(\STDOUT);
+        $stat = @fstat(\STDOUT);
 
         // Check if formatted mode is S_IFCHR
         return $stat ? 0020000 === ($stat['mode'] & 0170000) : false;