feat: Adds support for making batch calls.

README.md

@@ -54,6 +54,108 @@ const api = new TwistApi(tokenResponse.accessToken)
 const user = await api.users.getSessionUser()
 ```
 
+### Batch Requests
+
+The SDK supports making multiple API calls in a single HTTP request using the `/batch` endpoint. This can significantly improve performance when you need to fetch or update multiple resources.
+
+**Note:** Batch requests are completely optional. If you only need to make a single API call, simply call the method normally without the `{ batch: true }` option.
+
+#### How It Works
+
+To use batch requests:
+
+1. Pass `{ batch: true }` as the last parameter to any API method
+2. This returns a `BatchRequestDescriptor` instead of executing the request immediately
+3. Pass multiple descriptors to `api.batch()` to execute them together
+
+```typescript
+// Single requests (normal usage)
+const user1 = await api.workspaceUsers.getUserById(123, 456)
+const user2 = await api.workspaceUsers.getUserById(123, 789)
+
+// Batch requests - executes in a single HTTP call
+const results = await api.batch(
+    api.workspaceUsers.getUserById(123, 456, { batch: true }),
+    api.workspaceUsers.getUserById(123, 789, { batch: true })
+)
+
+console.log(results[0].data.name) // First user
+console.log(results[1].data.name) // Second user
+```
+
+#### Response Structure
+
+Each item in the batch response includes:
+
+- `code` - HTTP status code for that specific request (e.g., 200, 404)
+- `headers` - Response headers as a key-value object
+- `data` - The parsed and validated response data
+
+```typescript
+const results = await api.batch(
+    api.channels.getChannel(123, { batch: true }),
+    api.channels.getChannel(456, { batch: true })
+)
+
+results.forEach((result) => {
+    if (result.code === 200) {
+        console.log('Success:', result.data.name)
+    } else {
+        console.error('Error:', result.code)
+    }
+})
+```
+
+#### Performance Optimization
+
+When all requests in a batch are GET requests, they are executed in parallel on the server for optimal performance. Mixed GET and POST requests are executed sequentially.
+
+```typescript
+// These GET requests execute in parallel
+const results = await api.batch(
+    api.workspaceUsers.getUserById(123, 456, { batch: true }),
+    api.channels.getChannel(789, { batch: true }),
+    api.threads.getThread(101112, { batch: true })
+)
+```
+
+#### Mixing Different API Calls
+
+You can batch requests across different resource types:
+
+```typescript
+const results = await api.batch(
+    api.workspaceUsers.getUserById(123, 456, { batch: true }),
+    api.channels.getChannels({ workspaceId: 123 }, { batch: true }),
+    api.conversations.getConversations({ workspaceId: 123 }, { batch: true })
+)
+
+const [user, channels, conversations] = results
+// TypeScript maintains proper types for each result
+console.log(user.data.name)
+console.log(channels.data.length)
+console.log(conversations.data.length)
+```
+
+#### Error Handling
+
+Individual requests in a batch can fail independently. Always check the status code of each result:
+
+```typescript
+const results = await api.batch(
+    api.channels.getChannel(123, { batch: true }),
+    api.channels.getChannel(999999, { batch: true }) // Non-existent channel
+)
+
+results.forEach((result, index) => {
+    if (result.code >= 200 && result.code < 300) {
+        console.log(`Request ${index} succeeded:`, result.data)
+    } else {
+        console.error(`Request ${index} failed with status ${result.code}`)
+    }
+})
+```
+
 ## Documentation
 
 For detailed documentation, visit the [Twist SDK Documentation](https://doist.github.io/twist-sdk-typescript/).

src/batch-builder.test.ts

@@ -0,0 +1,186 @@
+import { HttpResponse, http } from 'msw'
+import { beforeEach, describe, expect, it } from 'vitest'
+import { server } from './testUtils/msw-setup'
+import { TEST_API_TOKEN } from './testUtils/test-defaults'
+import { TwistApi } from './twist-api'
+
+describe('BatchBuilder', () => {
+    let api: TwistApi
+
+    beforeEach(() => {
+        api = new TwistApi(TEST_API_TOKEN)
+    })
+
+    describe('batch', () => {
+        it('should have a batch method', () => {
+            expect(typeof api.batch).toBe('function')
+        })
+    })
+
+    describe('add and execute', () => {
+        it('should batch multiple getUserById requests', async () => {
+            const mockUser1 = {
+                id: 456,
+                name: 'User One',
+                email: '[email protected]',
+                user_type: 'USER',
+                short_name: 'U1',
+                timezone: 'UTC',
+                removed: false,
+                bot: false,
+                version: 1,
+            }
+
+            const mockUser2 = {
+                id: 789,
+                name: 'User Two',
+                email: '[email protected]',
+                user_type: 'USER',
+                short_name: 'U2',
+                timezone: 'UTC',
+                removed: false,
+                bot: false,
+                version: 1,
+            }
+
+            server.use(
+                http.post('https://api.twist.com/api/v3/batch', async ({ request }) => {
+                    const body = await request.text()
+                    const params = new URLSearchParams(body)
+                    const requestsStr = params.get('requests')
+                    const parallel = params.get('parallel')
+
+                    expect(requestsStr).toBeDefined()
+                    expect(parallel).toBe('true') // All GET requests
+
+                    const requests = JSON.parse(requestsStr!)
+                    expect(requests).toHaveLength(2)
+                    expect(requests[0].method).toBe('GET')
+                    expect(requests[0].url).toContain('workspace_users/getone')
+                    expect(requests[0].url).toContain('user_id=456')
+                    expect(requests[1].url).toContain('user_id=789')
+
+                    return HttpResponse.json([
+                        {
+                            code: 200,
+                            headers: '',
+                            body: JSON.stringify(mockUser1),
+                        },
+                        {
+                            code: 200,
+                            headers: '',
+                            body: JSON.stringify(mockUser2),
+                        },
+                    ])
+                }),
+            )
+
+            const results = await api.batch(
+                api.workspaceUsers.getUserById(123, 456, { batch: true }),
+                api.workspaceUsers.getUserById(123, 789, { batch: true }),
+            )
+
+            expect(results).toHaveLength(2)
+            expect(results[0].code).toBe(200)
+            expect(results[0].data.id).toBe(456)
+            expect(results[0].data.name).toBe('User One')
+            expect(results[1].code).toBe(200)
+            expect(results[1].data.id).toBe(789)
+            expect(results[1].data.name).toBe('User Two')
+        })
+
+        it('should handle empty batch', async () => {
+            const results = await api.batch()
+            expect(results).toEqual([])
+        })
+
+        it('should handle error responses in batch', async () => {
+            server.use(
+                http.post('https://api.twist.com/api/v3/batch', async () => {
+                    return HttpResponse.json([
+                        {
+                            code: 200,
+                            headers: '',
+                            body: JSON.stringify({
+                                id: 456,
+                                name: 'User One',
+                                email: '[email protected]',
+                                user_type: 'USER',
+                                short_name: 'U1',
+                                timezone: 'UTC',
+                                removed: false,
+                                bot: false,
+                                version: 1,
+                            }),
+                        },
+                        {
+                            code: 404,
+                            headers: '',
+                            body: JSON.stringify({ error: 'User not found' }),
+                        },
+                    ])
+                }),
+            )
+
+            const results = await api.batch(
+                api.workspaceUsers.getUserById(123, 456, { batch: true }),
+                api.workspaceUsers.getUserById(123, 999, { batch: true }),
+            )
+
+            expect(results).toHaveLength(2)
+            expect(results[0].code).toBe(200)
+            expect(results[0].data.name).toBe('User One')
+            expect(results[1].code).toBe(404)
+            // Type assertion needed for error responses - error responses don't match the expected type
+            expect((results[1].data as unknown as { error: string }).error).toBe('User not found')
+        })
+
+        it('should accept array of descriptors', () => {
+            const descriptors = [
+                api.workspaceUsers.getUserById(123, 456, { batch: true }),
+                api.workspaceUsers.getUserById(123, 789, { batch: true }),
+            ]
+            expect(descriptors).toHaveLength(2)
+            expect(descriptors[0].method).toBe('GET')
+            expect(descriptors[0].url).toBe('workspace_users/getone')
+        })
+    })
+
+    describe('getUserById with batch option', () => {
+        it('should return descriptor when batch: true', () => {
+            const descriptor = api.workspaceUsers.getUserById(123, 456, { batch: true })
+
+            expect(descriptor).toEqual({
+                method: 'GET',
+                url: 'workspace_users/getone',
+                params: { id: 123, user_id: 456 },
+                schema: expect.any(Object), // WorkspaceUserSchema
+            })
+        })
+
+        it('should return promise when batch is not specified', async () => {
+            server.use(
+                http.get('https://api.twist.com/api/v4/workspace_users/getone', async () => {
+                    return HttpResponse.json({
+                        id: 456,
+                        name: 'User One',
+                        email: '[email protected]',
+                        user_type: 'USER',
+                        short_name: 'U1',
+                        timezone: 'UTC',
+                        removed: false,
+                        bot: false,
+                        version: 1,
+                    })
+                }),
+            )
+
+            const result = api.workspaceUsers.getUserById(123, 456)
+            expect(result).toBeInstanceOf(Promise)
+
+            const user = await result
+            expect(user.id).toBe(456)
+            expect(user.name).toBe('User One')
+        })
+    })
+})