AT- 416 Added functionality to fetch PR title & description from Mermaid AI via pr-summary endpoint

packages/sdk/src/index.test.ts

@@ -2,6 +2,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest';
 import { MermaidChart } from './index.js';
 import { AICreditsLimitExceededError } from './errors.js';
 import type { AuthorizationData } from './types.js';
+import { URLS } from './urls.js';
 
 import { OAuth2Client } from '@badgateway/oauth2-client';
 
@@ -171,4 +172,52 @@ describe('MermaidChart', () => {
       ).rejects.toThrow(AICreditsLimitExceededError);
     });
   });
+
+  describe('#suggestPrSummary', () => {
+    beforeEach(async () => {
+      await client.setAccessToken('test-access-token');
+    });
+
+    it('should POST to the pr-summary endpoint with the request body and return response.data', async () => {
+      const jsonResponse = {
+        title: 'Add validation step to flowchart',
+        description: '## What changed\n- Added node C',
+        branchName: 'feature/flowchart-validation',
+        commitMessage: 'Add validation node C',
+      };
+
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const postSpy = vi.spyOn((client as any).axios, 'post').mockResolvedValue({
+        data: jsonResponse,
+      });
+
+      const requestBody = {
+        originalDiagram: 'flowchart TD\n  A --> B',
+        editedDiagram: 'flowchart TD\n  A --> B\n  B --> C[Validate]',
+      };
+
+      const result = await client.suggestPrSummary(requestBody);
+
+      expect(postSpy).toHaveBeenCalledWith(URLS.rest.openai.prSummary, requestBody);
+      expect(result).toEqual(jsonResponse);
+    });
+
+    it('should throw AICreditsLimitExceededError on 402', async () => {
+      // Mock the underlying axios call so the error mapping in suggestPrSummary is exercised.
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      vi.spyOn((client as any).axios, 'post').mockRejectedValue({
+        response: {
+          status: 402,
+          data: 'AI credits limit exceeded',
+        },
+      });
+
+      await expect(
+        client.suggestPrSummary({
+          originalDiagram: 'flowchart TD\n  A --> B',
+          editedDiagram: 'flowchart TD\n  A --> B\n  B --> C',
+        }),
+      ).rejects.toThrow(AICreditsLimitExceededError);
+    });
+  });
 });

packages/sdk/src/index.ts

@@ -19,6 +19,8 @@ import type {
   MCUser,
   RepairDiagramRequest,
   RepairDiagramResponse,
+  PrSummaryRequest,
+  PrSummaryResponse,
   AICreditsUsage,
 } from './types.js';
 import { URLS } from './urls.js';
@@ -330,6 +332,25 @@ export class MermaidChart {
     }
   }
 
+  /**
+   * Suggests a pull request title and body (markdown) from a before/after diagram diff (Mermaid AI).
+   * The response also include  `branchName` and `commitMessage`.
+   *
+   * @param request - `originalDiagram` and `editedDiagram` only
+   * @throws {@link AICreditsLimitExceededError} if credits limit exceeded (HTTP 402)
+   */
+  public async suggestPrSummary(request: PrSummaryRequest): Promise<PrSummaryResponse> {
+    try {
+      const response = await this.axios.post<PrSummaryResponse>(
+        URLS.rest.openai.prSummary,
+        request,
+      );
+      return response.data;
+    } catch (error: unknown) {
+      throwIfAICreditsExceeded(error);
+    }
+  }
+
   /**
    * Chat with Mermaid AI about a diagram.
    *

packages/sdk/src/types.ts

@@ -96,6 +96,24 @@ export interface RepairDiagramRequest {
   userID?: string;
 }
 
+/**
+ * Only the two diagram versions are sent; the server derives user plan and usage from the auth context provided by the access token.
+ */
+export interface PrSummaryRequest {
+  originalDiagram: string;
+  editedDiagram: string;
+}
+
+/**
+ * Public response: suggested PR title and markdown description, branch name, and commit message.
+ */
+export interface PrSummaryResponse {
+  title: string;
+  description: string;
+  branchName?: string;
+  commitMessage?: string;
+}
+
 /**
  * Request parameters for chatting with the Mermaid AI about a diagram.
  */

packages/sdk/src/urls.ts

@@ -41,6 +41,7 @@ export const URLS = {
     },
     openai: {
       repair: `/rest-api/openai/repair`,
+      prSummary: `/rest-api/openai/pr-summary`,
       chat: `/rest-api/openai/chat`,
     },
   },