From d8abf9f44f235f63d7f56eb9e5ca66618e4f1874 Mon Sep 17 00:00:00 2001
From: Paul O'Reilly <paul@upware.dev>
Date: Fri, 22 Nov 2024 09:56:40 +0100
Subject: [PATCH] feat: ability to merge routers with same alias. references
 kevinedry/nestjs-trpc#42

---
 .../__tests__/router.generator.spec.ts        | 47 ++++++++++++++++---
 .../lib/generators/router.generator.ts        | 18 +++++--
 2 files changed, 55 insertions(+), 10 deletions(-)

diff --git a/packages/nestjs-trpc/lib/generators/__tests__/router.generator.spec.ts b/packages/nestjs-trpc/lib/generators/__tests__/router.generator.spec.ts
index e76a669..4a91fd8 100644
--- a/packages/nestjs-trpc/lib/generators/__tests__/router.generator.spec.ts
+++ b/packages/nestjs-trpc/lib/generators/__tests__/router.generator.spec.ts
@@ -2,12 +2,8 @@ import { Test, TestingModule } from '@nestjs/testing';
 import { RouterGenerator } from '../router.generator';
 import { DecoratorGenerator } from '../decorator.generator';
 import { Project, SourceFile } from 'ts-morph';
-import { RoutersFactoryMetadata, } from '../../interfaces/factory.interface';
-import {
-  DecoratorGeneratorMetadata,
-  ProcedureGeneratorMetadata,
-  RouterGeneratorMetadata,
-} from '../../interfaces/generator.interface';
+import { RoutersFactoryMetadata } from '../../interfaces/factory.interface';
+import { DecoratorGeneratorMetadata, RouterGeneratorMetadata } from '../../interfaces/generator.interface';
 import { Query, Mutation } from '../../decorators';
 import { z } from 'zod';
 import { ProcedureGenerator } from '../procedure.generator';
@@ -178,5 +174,44 @@ describe('RouterGenerator', () => {
         '})'
       );
     });
+
+    it.only('should generate merged router string from metadata', () => {
+      const mockRouterMetadata: Array<RouterGeneratorMetadata> = [
+        {
+          name: 'TestRouter',
+          alias: 'test',
+          procedures: [
+            {
+              name: 'testQuery',
+              decorators: [{ name: 'Query', arguments: {} }],
+            },
+            {
+              name: 'testMutation',
+              decorators: [{ name: 'Mutation', arguments: {} }],
+            },
+          ],
+        },
+        {
+          name: 'TestRouter',
+          alias: 'test',
+          procedures: [
+            {
+              name: 'testQueryExtended',
+              decorators: [{ name: 'Query', arguments: {} }],
+            },
+          ],
+        },
+      ];
+
+      const result = routerGenerator.generateRoutersStringFromMetadata(mockRouterMetadata);
+
+      expect(result).toBe(
+        'test: t.router({ ' +
+        'testQuery: publicProcedure.query(async () => "PLACEHOLDER_DO_NOT_REMOVE" as any ),\n' +
+        'testMutation: publicProcedure.mutation(async () => "PLACEHOLDER_DO_NOT_REMOVE" as any ),\n ' +
+        'testQueryExtended: publicProcedure.query(async () => "PLACEHOLDER_DO_NOT_REMOVE" as any ) ' +
+        '})'
+      );
+    });
   });
 });
\ No newline at end of file
diff --git a/packages/nestjs-trpc/lib/generators/router.generator.ts b/packages/nestjs-trpc/lib/generators/router.generator.ts
index 6482b2d..d432b25 100644
--- a/packages/nestjs-trpc/lib/generators/router.generator.ts
+++ b/packages/nestjs-trpc/lib/generators/router.generator.ts
@@ -85,10 +85,20 @@ export class RouterGenerator {
   public generateRoutersStringFromMetadata(
     routers: Array<RouterGeneratorMetadata>,
   ): string {
-    return routers
-      .map((router) => {
-        const { name, procedures, alias } = router;
-        return `${alias ?? camelCase(name)}: t.router({ ${procedures
+    const routersMap: { [key: string]: ProcedureGeneratorMetadata[] } = {};
+
+    routers.forEach((router) => {
+      const { name, procedures, alias } = router;
+      const routerName = alias ?? camelCase(name);
+
+      routersMap[routerName] = (routersMap[routerName] ?? []).concat(
+        procedures,
+      );
+    });
+
+    return Object.entries(routersMap)
+      .map(([routerName, procedures]) => {
+        return `${routerName}: t.router({ ${procedures
           .map(this.procedureGenerator.generateProcedureString)
           .join(',\n')} })`;
       })