feat(cli): add /chat debug command for nightly builds (#16339)

packages/core/src/utils/apiConversionUtils.ts

@@ -0,0 +1,57 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { GenerateContentParameters } from '@google/genai';
+
+/**
+ * Transforms a standard SDK GenerateContentParameters object into the
+ * equivalent REST API payload format. This is primarily used for debugging
+ * and exporting requests.
+ */
+export function convertToRestPayload(
+  req: GenerateContentParameters,
+): Record<string, unknown> {
+  // Extract top-level REST fields from the SDK config object.
+  // 'pureGenerationConfig' will capture any remaining hyperparameters (e.g., temperature, topP).
+  const {
+    systemInstruction: sdkSystemInstruction,
+    tools: sdkTools,
+    toolConfig: sdkToolConfig,
+    safetySettings: sdkSafetySettings,
+    cachedContent: sdkCachedContent,
+    abortSignal: _sdkAbortSignal, // Exclude JS-specific abort controller
+    ...pureGenerationConfig
+  } = req.config || {};
+
+  // Normalize systemInstruction to the expected REST Content format.
+  let restSystemInstruction;
+  if (typeof sdkSystemInstruction === 'string') {
+    restSystemInstruction = {
+      parts: [{ text: sdkSystemInstruction }],
+    };
+  } else if (sdkSystemInstruction !== undefined) {
+    restSystemInstruction = sdkSystemInstruction;
+  }
+
+  const restPayload: Record<string, unknown> = {
+    contents: req.contents,
+  };
+
+  // Only include generationConfig if actual hyperparameters exist.
+  if (Object.keys(pureGenerationConfig).length > 0) {
+    restPayload['generationConfig'] = pureGenerationConfig;
+  }
+
+  // Assign extracted capabilities to the root level.
+  if (restSystemInstruction)
+    restPayload['systemInstruction'] = restSystemInstruction;
+  if (sdkTools) restPayload['tools'] = sdkTools;
+  if (sdkToolConfig) restPayload['toolConfig'] = sdkToolConfig;
+  if (sdkSafetySettings) restPayload['safetySettings'] = sdkSafetySettings;
+  if (sdkCachedContent) restPayload['cachedContent'] = sdkCachedContent;
+
+  return restPayload;
+}