Properly handle prompt exceptions

Author: josbeir

src/Prompts/AbstractPrompt.php

@@ -4,6 +4,7 @@
 namespace Synapse\Prompts;
 
 use Cake\Core\Configure;
+use Mcp\Exception\PromptGetException;
 
 /**
  * Abstract Prompt Base Class
@@ -30,4 +31,82 @@ public function __construct()
         $this->cakephpVersion = Configure::read('Synapse.prompts.cakephp_version', '5.x');
         $this->phpVersion = Configure::read('Synapse.prompts.php_version', '8.2');
     }
+
+    /**
+     * Validate that a parameter value is one of the allowed values
+     *
+     * @param string $value The parameter value
+     * @param array<string> $allowed Allowed values
+     * @param string $paramName The parameter name (for error message)
+     * @param string $promptName The prompt name (for error message)
+     * @throws \Mcp\Exception\PromptGetException
+     */
+    protected function validateEnumParameter(
+        string $value,
+        array $allowed,
+        string $paramName,
+        string $promptName,
+    ): void {
+        if (!in_array($value, $allowed, true)) {
+            $allowedStr = implode(', ', $allowed);
+            throw new PromptGetException(
+                sprintf("Invalid value for parameter '%s': '%s'. ", $paramName, $value) .
+                sprintf('Expected one of: %s. ', $allowedStr) .
+                'Prompt: ' . $promptName,
+            );
+        }
+    }
+
+    /**
+     * Validate that a parameter is not empty
+     *
+     * @param string $value The parameter value
+     * @param string $paramName The parameter name (for error message)
+     * @param string $promptName The prompt name (for error message)
+     * @throws \Mcp\Exception\PromptGetException
+     */
+    protected function validateNonEmptyParameter(
+        string $value,
+        string $paramName,
+        string $promptName,
+    ): void {
+        if ($value === '' || $value === '0') {
+            throw new PromptGetException(
+                sprintf("Parameter '%s' cannot be empty. Prompt: %s", $paramName, $promptName),
+            );
+        }
+    }
+
+    /**
+     * Validate comma-separated values against allowed list
+     *
+     * @param string $value Comma-separated values
+     * @param array<string> $allowed Allowed values
+     * @param string $paramName The parameter name (for error message)
+     * @param string $promptName The prompt name (for error message)
+     * @throws \Mcp\Exception\PromptGetException
+     */
+    protected function validateCommaSeparatedParameter(
+        string $value,
+        array $allowed,
+        string $paramName,
+        string $promptName,
+    ): void {
+        if ($value === '' || $value === '0') {
+            return;
+        }
+
+        $values = array_map('trim', explode(',', $value));
+        $invalid = array_diff($values, $allowed);
+
+        if ($invalid !== []) {
+            $invalidStr = implode(', ', $invalid);
+            $allowedStr = implode(', ', $allowed);
+            throw new PromptGetException(
+                sprintf("Invalid values for parameter '%s': %s. ", $paramName, $invalidStr) .
+                sprintf('Expected one of: %s. ', $allowedStr) .
+                'Prompt: ' . $promptName,
+            );
+        }
+    }
 }

src/Prompts/CodeReviewerPrompt.php

@@ -30,6 +30,13 @@ public function handle(
         string $code,
         string $focus = 'all',
     ): array {
+        $this->validateEnumParameter(
+            $focus,
+            ['conventions', 'security', 'performance', 'testing', 'all'],
+            'focus',
+            'code-reviewer',
+        );
+
         return [
             new PromptMessage(
                 role: Role::User,

src/Prompts/DatabaseExplorerPrompt.php

@@ -30,6 +30,14 @@ public function handle(
         string $table,
         string $show = 'all',
     ): array {
+        $this->validateNonEmptyParameter($table, 'table', 'database-explorer');
+        $this->validateEnumParameter(
+            $show,
+            ['schema', 'data', 'relationships', 'all'],
+            'show',
+            'database-explorer',
+        );
+
         return [
             new PromptMessage(
                 role: Role::User,

src/Prompts/DebugHelperPrompt.php

@@ -30,6 +30,15 @@ public function handle(
         string $error,
         string $context = '',
     ): array {
+        if ($context !== '' && $context !== '0') {
+            $this->validateEnumParameter(
+                $context,
+                ['controller', 'model', 'database', 'view'],
+                'context',
+                'debug-helper',
+            );
+        }
+
         $contextHint = $context !== '' && $context !== '0' ? sprintf(' in the %s layer', $context) : '';
 
         return [

src/Prompts/DocumentationExpertPrompt.php

@@ -30,6 +30,13 @@ public function handle(
         string $topic,
         string $depth = 'intermediate',
     ): array {
+        $this->validateEnumParameter(
+            $depth,
+            ['basic', 'intermediate', 'advanced'],
+            'depth',
+            'documentation-expert',
+        );
+
         return match ($depth) {
             'basic' => $this->getBasicDocumentationMessages($topic),
             'advanced' => $this->getAdvancedDocumentationMessages($topic),

src/Prompts/FeatureBuilderPrompt.php

@@ -30,6 +30,13 @@ public function handle(
         string $feature,
         string $component = 'full-stack',
     ): array {
+        $this->validateEnumParameter(
+            $component,
+            ['controller', 'model', 'behavior', 'helper', 'middleware', 'command', 'full-stack'],
+            'component',
+            'feature-builder',
+        );
+
         return [
             new PromptMessage(
                 role: Role::User,

src/Prompts/MigrationGuidePrompt.php

@@ -32,6 +32,9 @@ public function handle(
         string $toVersion,
         string $area = 'general',
     ): array {
+        $this->validateNonEmptyParameter($fromVersion, 'fromVersion', 'migration-guide');
+        $this->validateNonEmptyParameter($toVersion, 'toVersion', 'migration-guide');
+
         return [
             new PromptMessage(
                 role: Role::User,

src/Prompts/OrmQueryHelperPrompt.php

@@ -30,6 +30,8 @@ public function handle(
         string $queryGoal,
         string $tables = '',
     ): array {
+        $this->validateNonEmptyParameter($queryGoal, 'queryGoal', 'orm-query-helper');
+
         $tablesHint = $tables !== '' && $tables !== '0' ? '
 Tables involved: ' . $tables : '';
 

src/Prompts/PerformanceAnalyzerPrompt.php

@@ -30,6 +30,8 @@ public function handle(
         string $concern,
         string $context = '',
     ): array {
+        $this->validateNonEmptyParameter($concern, 'concern', 'performance-analyzer');
+
         $contextSection = $context !== '' && $context !== '0' ? '
 
 Context:

src/Prompts/QualityAssurancePrompt.php

@@ -55,6 +55,21 @@ public function handle(
         string $context = 'all',
         string $tools = 'all',
     ): array {
+        $this->validateEnumParameter(
+            $context,
+            ['guidelines', 'integration', 'troubleshooting', 'all'],
+            'context',
+            'quality-assurance',
+        );
+
+        $allowedTools = array_keys($this->qualityTools);
+        $this->validateCommaSeparatedParameter(
+            $tools,
+            array_merge($allowedTools, ['all']),
+            'tools',
+            'quality-assurance',
+        );
+
         $enabledTools = $this->getEnabledTools($tools);
 
         if ($enabledTools === []) {