Suppress warnings when --no-output is specified

src/Psalm/Config.php

@@ -60,7 +60,6 @@
 use function class_exists;
 use function clearstatcache;
 use function count;
-use function defined;
 use function dirname;
 use function explode;
 use function extension_loaded;
@@ -70,7 +69,6 @@
 use function filetype;
 use function flock;
 use function fopen;
-use function fwrite;
 use function get_class;
 use function get_defined_constants;
 use function get_defined_functions;
@@ -124,7 +122,6 @@
 use const PHP_VERSION_ID;
 use const PSALM_VERSION;
 use const SCANDIR_SORT_NONE;
-use const STDERR;
 
 /**
  * @psalm-suppress PropertyNotSetInConstructor
@@ -705,6 +702,9 @@ class Config
      */
     private array $plugins = [];
 
+    /** @var list<string> */
+    public array $config_warnings = [];
+
     /** @internal */
     protected function __construct()
     {
@@ -1179,18 +1179,18 @@ private static function fromXmlAndPaths(
             $config->use_igbinary = version_compare($igbinary_version, '2.0.5') >= 0;
         }
 
-        if (!isset($config_xml['findUnusedBaselineEntry']) && !defined('__IS_TEST_ENV__')) {
-            fwrite(STDERR, 'Warning: "findUnusedBaselineEntry" will be defaulted to "true" in Psalm 6. You should'
-                         . ' explicitly enable or disable this setting.' . PHP_EOL);
+        if (!isset($config_xml['findUnusedBaselineEntry'])) {
+            $config->config_warnings[] = '"findUnusedBaselineEntry" will be defaulted to "true" in Psalm 6.'
+                . ' You should explicitly enable or disable this setting.';
         }
 
         if (isset($config_xml['findUnusedCode'])) {
             $attribute_text = (string) $config_xml['findUnusedCode'];
             $config->find_unused_code = $attribute_text === 'true' || $attribute_text === '1';
             $config->find_unused_variables = $config->find_unused_code;
-        } elseif (!defined('__IS_TEST_ENV__')) {
-            fwrite(STDERR, 'Warning: "findUnusedCode" will be defaulted to "true" in Psalm 6. You should explicitly'
-                . ' enable or disable this setting.' . PHP_EOL);
+        } else {
+            $config->config_warnings[] = '"findUnusedCode" will be defaulted to "true" in Psalm 6.'
+                . ' You should explicitly enable or disable this setting.';
         }
 
         if (isset($config_xml['findUnusedVariablesAndParams'])) {

src/Psalm/Internal/Cli/Psalm.php

@@ -597,6 +597,10 @@ private static function initProgress(array $options, Config $config): Progress
                 $progress = new DefaultProgress($show_errors, $show_info);
             }
         }
+        // output buffered warnings
+        foreach ($config->config_warnings as $warning) {
+            $progress->warning($warning);
+        }
         return $progress;
     }
 

src/Psalm/Progress/Progress.php

@@ -9,6 +9,7 @@
 use function stripos;
 
 use const E_ERROR;
+use const PHP_EOL;
 use const PHP_OS;
 use const STDERR;
 
@@ -56,6 +57,11 @@ public function write(string $message): void
         fwrite(STDERR, $message);
     }
 
+    public function warning(string $message): void
+    {
+        $this->write('Warning: ' . $message . PHP_EOL);
+    }
+
     protected static function doesTerminalSupportUtf8(): bool
     {
         if (stripos(PHP_OS, 'WIN') === 0) {

tests/EndToEnd/PsalmEndToEndTest.php

@@ -231,6 +231,19 @@ public function testLegacyConfigWithoutresolveFromConfigFile(): void
         $this->assertStringContainsString('InvalidReturnType', $process->getOutput());
     }
 
+    public function testPsalmWithNoProgressDoesNotProduceOutputOnStderr(): void
+    {
+        $this->runPsalmInit();
+
+        $psalmXml = file_get_contents(self::$tmpDir . '/psalm.xml');
+        $psalmXml = preg_replace('/findUnusedCode="(true|false)"/', '', $psalmXml);
+        file_put_contents(self::$tmpDir . '/psalm.xml', $psalmXml);
+
+        $result = $this->runPsalm(['--no-progress'], self::$tmpDir);
+
+        $this->assertSame('', $result['STDERR']);
+    }
+
     /**
      * @return array{STDOUT: string, STDERR: string, CODE: int|null}
      */