Merge pull request #84 from mizdra/implement-build-connection

Implement `buildConnection()`

Author: mizdra

README.md

@@ -233,6 +233,30 @@ expect(await BookFactory.buildList(3)).toStrictEqual([
 ]);
 ```
 
+### Building connection
+
+You can build a [connection](https://relay.dev/graphql/connections.htm) of mock data with the `buildConnection` method.
+
+```ts
+const BookFactory = defineBookFactory({
+  defaultFields: {
+    id: dynamic(({ seq }) => `Book-${seq}`),
+  },
+});
+expect(await BookFactory.buildConnection(3, { first: 2 })).toStrictEqual([
+  edges: [
+    { cursor: "YXJyYXljb25uZWN0aW9uOjA=", node: { id: 'Book-0' } },
+    { cursor: "YXJyYXljb25uZWN0aW9uOjE=", node: { id: 'Book-1' } },
+  ],
+  pageInfo: {
+    startCursor: "YXJyYXljb25uZWN0aW9uOjA=",
+    endCursor: "YXJyYXljb25uZWN0aW9uOjE=",
+    hasPreviousPage: false,
+    hasNextPage: true,
+  },
+]);
+```
+
 ### Build mock data of related types (a.k.a. Associations)
 
 You can build mock data of the relevant type in one shot.

e2e/esm/index.e2e.ts

@@ -22,6 +22,7 @@ import { oneOf } from './test/util.js';
 import { definePrefixTypeFactory } from './__generated__/2-typesPrefix/fabbrica.js';
 import { defineTypeSuffixFactory } from './__generated__/3-typesSuffix/fabbrica.js';
 import { defineNonOptionalDefaultFields_NonOptionalDefaultFieldsTypeFactory } from './__generated__/4-non-optional-fields/fabbrica.js';
+import { offsetToCursor } from 'graphql-relay';
 
 describe('integration test', () => {
   it('circular dependent type', async () => {
@@ -1017,6 +1018,37 @@ describe('TypeFactoryInterface', () => {
       >();
     });
   });
+  describe('buildConnection', () => {
+    it('build connection', async () => {
+      const BookFactory = defineBookFactory({
+        defaultFields: {
+          id: dynamic(({ seq }) => `Book-${seq}`),
+        },
+      });
+      const books1 = await BookFactory.buildConnection(3, { first: 2 });
+      expect(books1).toStrictEqual({
+        edges: [
+          { cursor: offsetToCursor(0), node: { id: 'Book-0' } },
+          { cursor: offsetToCursor(1), node: { id: 'Book-1' } },
+        ],
+        pageInfo: {
+          startCursor: offsetToCursor(0),
+          endCursor: offsetToCursor(1),
+          hasPreviousPage: false,
+          hasNextPage: true,
+        },
+      });
+      expectTypeOf(books1).toEqualTypeOf<{
+        edges: { cursor: string; node: { id: string } }[];
+        pageInfo: {
+          startCursor: string | null;
+          endCursor: string | null;
+          hasPreviousPage: boolean;
+          hasNextPage: boolean;
+        };
+      }>();
+    });
+  });
   describe('resetSequence', () => {
     it('resets sequence', async () => {
       const BookFactory = defineBookFactory({

package-lock.json

@@ -97,6 +97,7 @@
   },
   "dependencies": {
     "@graphql-codegen/plugin-helpers": "^5.0.1",
-    "@graphql-codegen/visitor-plugin-common": "^4.0.1"
+    "@graphql-codegen/visitor-plugin-common": "^4.0.1",
+    "graphql-relay": "^0.10.2"
   }
 }

package.json

@@ -1,5 +1,6 @@
 // MEMO: The tests for this module are covered by `e2e/*.e2e.ts`.
 
+import { Connection, ConnectionArguments, connectionFromArray } from 'graphql-relay';
 import { ResolvedFields, FieldsResolver, resolveFields, FieldResolver } from './field-resolver.js';
 import { getSequenceCounter, resetSequence } from './sequence.js';
 import { Merge } from './util.js';
@@ -40,6 +41,17 @@ export interface TypeFactoryInterface<
     count: number,
     inputFieldsResolver: T,
   ): Promise<Omit<Merge<ResolvedFields<_DefaultFieldsResolver>, ResolvedFields<T>>, keyof TransientFields>[]>;
+  buildConnection(
+    count: number,
+    connectionArgs: ConnectionArguments,
+  ): Promise<
+    Connection<Omit<Merge<ResolvedFields<_DefaultFieldsResolver>, ResolvedFields<{}>>, keyof TransientFields>>
+  >;
+  buildConnection<T extends FieldsResolver<Type & TransientFields>>(
+    count: number,
+    connectionArgs: ConnectionArguments,
+    inputFieldsResolver: T,
+  ): Promise<Connection<Omit<Merge<ResolvedFields<_DefaultFieldsResolver>, ResolvedFields<T>>, keyof TransientFields>>>;
   use<T extends keyof _Traits>(
     traitName: T,
   ): TypeFactoryInterface<Type, TransientFields, Merge<_DefaultFieldsResolver, _Traits[T]['defaultFields']>, _Traits>;
@@ -119,6 +131,22 @@ export function defineTypeFactoryInternal<
       }
       return array;
     },
+    async buildConnection<T extends FieldsResolver<Type & TransientFields>>(
+      count: number,
+      connectionArgs: ConnectionArguments,
+      inputFieldsResolver?: T,
+    ): Promise<
+      Connection<Omit<Merge<ResolvedFields<_DefaultFieldsResolver>, ResolvedFields<T>>, keyof TransientFields>>
+    > {
+      const list = inputFieldsResolver ? await this.buildList(count, inputFieldsResolver) : await this.buildList(count);
+      return connectionFromArray(
+        list as readonly Omit<
+          Merge<ResolvedFields<_DefaultFieldsResolver>, ResolvedFields<T>>,
+          keyof TransientFields
+        >[],
+        connectionArgs,
+      );
+    },
     use<T extends keyof _Traits>(
       traitName: T,
     ): TypeFactoryInterface<