feat(envconfig): Add default config file detection

Author: roxblnfk

src/Common/EnvConfig/Client/ConfigEnv.php

@@ -47,6 +47,10 @@ public function __construct(
          * @var non-empty-lowercase-string|null
          */
         public readonly ?string $currentProfile = null,
+        /**
+         * Path to TOML configuration file from TEMPORAL_CONFIG_FILE
+         * @var non-empty-string|null
+         */
         public readonly ?string $configFile = null,
     ) {}
 

src/Common/EnvConfig/ConfigClient.php

@@ -45,13 +45,15 @@ private function __construct(
      * This is the primary method for loading configuration with full control over sources.
      *
      * Loading order (later overrides earlier):
-     * 1. Profile from TOML file (if $configFile provided or found at default location)
+     * 1. Profile from TOML file (if $configFile provided, or TEMPORAL_CONFIG_FILE is set,
+     *    or file exists at default platform-specific location)
      * 2. Environment variable overrides (if $envProvider provided)
      *
      * @param non-empty-string|null $profileName Profile name to load. If null, uses TEMPORAL_PROFILE
      *        environment variable or 'default' as fallback.
      * @param non-empty-string|null $configFile Path to TOML config file or TOML content string.
-     *        If null, attempts to find config at default platform-specific location.
+     *        If null, checks TEMPORAL_CONFIG_FILE env var, then checks if file exists at
+     *        default platform-specific location.
      * @param EnvProvider $envProvider Environment variable provider for overrides.
      * @param bool $strict Whether to use strict TOML parsing (validates mutual exclusivity, etc.)
      *
@@ -69,7 +71,14 @@ public static function load(
         $profileName ??= $envConfig->currentProfile ?? 'default';
         $profileNameLower = \strtolower($profileName);
 
-        // Load from file
+        // Determine config file path: explicit > env var > default location
+        $configFile ??= $envConfig->configFile;
+        if ($configFile === null) {
+            $configFile = self::getDefaultConfigPath($envProvider);
+            $configFile === null or \file_exists($configFile) or $configFile = null;
+        }
+
+        // Load from file if it exists
         $profile = null;
         $profiles = [];
         if ($configFile !== null) {
@@ -181,4 +190,34 @@ private static function normalizeProfileNames(array $profiles): array
         }
         return $normalized;
     }
+
+    /**
+     * Get the default configuration file path based on the operating system.
+     *
+     * Returns the platform-specific path to temporal.toml configuration file:
+     * - Linux/Unix: $XDG_CONFIG_HOME/temporalio/temporal.toml (default: ~/.config/temporalio/temporal.toml)
+     * - macOS: ~/Library/Application Support/temporalio/temporal.toml
+     * - Windows: %APPDATA%/temporalio/temporal.toml
+     *
+     * Note: This method returns the expected path regardless of whether the file exists.
+     * The caller is responsible for checking file existence.
+     *
+     * @param EnvProvider $envProvider Environment variable provider
+     * @return non-empty-string|null Path to default config file, or null if home directory cannot be determined
+     */
+    private static function getDefaultConfigPath(EnvProvider $envProvider): ?string
+    {
+        $home = $envProvider->get('HOME') ?? $envProvider->get('USERPROFILE');
+        if ($home === null) {
+            return null;
+        }
+
+        $configDir = match (\PHP_OS_FAMILY) {
+            'Windows' => $envProvider->get('APPDATA') ?? ($home . '\\AppData\\Roaming'),
+            'Darwin' => $home . '/Library/Application Support',
+            default => $envProvider->get('XDG_CONFIG_HOME') ?? ($home . '/.config'),
+        };
+
+        return $configDir . \DIRECTORY_SEPARATOR . 'temporalio' . \DIRECTORY_SEPARATOR . 'temporal.toml';
+    }
 }