版本：11.x

服务器端调用

您可能需要直接从托管它们的同一服务器调用您的过程，createCallerFactory() 可用于实现此目的。这对于服务器端调用和 tRPC 过程的集成测试很有用。

信息

createCaller 不应用于从其他过程内部调用过程。这会通过（可能）再次创建上下文、执行所有中间件和验证输入来产生开销 - 所有这些操作在当前过程中已经完成。相反，您应该将共享逻辑提取到一个单独的函数中，并从过程内部调用该函数，如下所示

创建调用者

使用 t.createCallerFactory 函数，您可以创建任何路由器的服务器端调用者。您首先使用要调用的路由器作为参数调用 createCallerFactory，然后它返回一个函数，您可以在其中传入 Context 以进行后续过程调用。

基本示例

我们使用查询创建路由器以列出帖子，并使用变异来添加帖子，然后我们调用每个方法。

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
type Context = {
  foo: string;
};
 
const t = initTRPC.context<Context>().create();
 
const publicProcedure = t.procedure;
const { createCallerFactory, router } = t;
 
interface Post {
  id: string;
  title: string;
}
const posts: Post[] = [
  {
    id: '1',
    title: 'Hello world',
  },
];
const appRouter = router({
  post: router({
    add: publicProcedure
      .input(
        z.object({
          title: z.string().min(2),
        }),
      )
      .mutation((opts) => {
        const post: Post = {
          ...opts.input,
          id: `${Math.random()}`,
        };
        posts.push(post);
        return post;
      }),
    list: publicProcedure.query(() => posts),
  }),
});
 
// 1. create a caller-function for your router
const createCaller = createCallerFactory(appRouter);
 
// 2. create a caller using your `Context`
const caller = createCaller({
  foo: 'bar',
});
 
// 3. use the caller to add and list posts
const addedPost = await caller.post.add({
  title: 'How to make server-side call in tRPC',
});
 
const postList = await caller.post.list();
         
const postList: Post[]

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
type Context = {
  foo: string;
};
 
const t = initTRPC.context<Context>().create();
 
const publicProcedure = t.procedure;
const { createCallerFactory, router } = t;
 
interface Post {
  id: string;
  title: string;
}
const posts: Post[] = [
  {
    id: '1',
    title: 'Hello world',
  },
];
const appRouter = router({
  post: router({
    add: publicProcedure
      .input(
        z.object({
          title: z.string().min(2),
        }),
      )
      .mutation((opts) => {
        const post: Post = {
          ...opts.input,
          id: `${Math.random()}`,
        };
        posts.push(post);
        return post;
      }),
    list: publicProcedure.query(() => posts),
  }),
});
 
// 1. create a caller-function for your router
const createCaller = createCallerFactory(appRouter);
 
// 2. create a caller using your `Context`
const caller = createCaller({
  foo: 'bar',
});
 
// 3. use the caller to add and list posts
const addedPost = await caller.post.add({
  title: 'How to make server-side call in tRPC',
});
 
const postList = await caller.post.list();
         
const postList: Post[]

集成测试中的示例用法

摘自 https://github.com/trpc/examples-next-prisma-starter/blob/main/src/server/routers/post.test.ts

ts
import { inferProcedureInput } from '@trpc/server';
import { createContextInner } from '../context';
import { AppRouter, createCaller } from './_app';
test('add and get post', async () => {
  const ctx = await createContextInner({});
  const caller = createCaller(ctx);
  const input: inferProcedureInput<AppRouter['post']['add']> = {
    text: 'hello test',
    title: 'hello test',
  };
  const post = await caller.post.add(input);
  const byId = await caller.post.byId({ id: post.id });
  expect(byId).toMatchObject(input);
});

ts
import { inferProcedureInput } from '@trpc/server';
import { createContextInner } from '../context';
import { AppRouter, createCaller } from './_app';
test('add and get post', async () => {
  const ctx = await createContextInner({});
  const caller = createCaller(ctx);
  const input: inferProcedureInput<AppRouter['post']['add']> = {
    text: 'hello test',
    title: 'hello test',
  };
  const post = await caller.post.add(input);
  const byId = await caller.post.byId({ id: post.id });
  expect(byId).toMatchObject(input);
});

`router.createCaller()`

注意

router.createCaller() 已被弃用，将在 tRPC 的 v11 或 v12 中删除。

使用 router.createCaller({}) 函数（第一个参数是 Context），我们检索 RouterCaller 的实例。

输入查询示例

我们使用输入查询创建路由器，然后调用异步 greeting 过程以获取结果。

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
const t = initTRPC.create();
 
const router = t.router({
  // Create procedure at path 'greeting'
  greeting: t.procedure
    .input(z.object({ name: z.string() }))
    .query((opts) => `Hello ${opts.input.name}`),
});
 
const caller = router.createCaller({});
const result = await caller.greeting({ name: 'tRPC' });
        
const result: string

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
const t = initTRPC.create();
 
const router = t.router({
  // Create procedure at path 'greeting'
  greeting: t.procedure
    .input(z.object({ name: z.string() }))
    .query((opts) => `Hello ${opts.input.name}`),
});
 
const caller = router.createCaller({});
const result = await caller.greeting({ name: 'tRPC' });
        
const result: string

变异示例

我们使用变异创建路由器，然后调用异步 post 过程以获取结果。

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
const posts = ['One', 'Two', 'Three'];
 
const t = initTRPC.create();
const router = t.router({
  post: t.router({
    add: t.procedure.input(z.string()).mutation((opts) => {
      posts.push(opts.input);
      return posts;
    }),
  }),
});
 
const caller = router.createCaller({});
const result = await caller.post.add('Four');
        
const result: string[]

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
const posts = ['One', 'Two', 'Three'];
 
const t = initTRPC.create();
const router = t.router({
  post: t.router({
    add: t.procedure.input(z.string()).mutation((opts) => {
      posts.push(opts.input);
      return posts;
    }),
  }),
});
 
const caller = router.createCaller({});
const result = await caller.post.add('Four');
        
const result: string[]

带有中间件的上下文示例

我们创建一个中间件来在执行 secret 过程之前检查上下文。以下是两个示例：前者失败，因为上下文不符合中间件逻辑，而后者则正常工作。

信息

中间件在调用任何过程之前执行。

ts
import { initTRPC, TRPCError } from '@trpc/server';
 
type Context = {
  user?: {
    id: string;
  };
};
const t = initTRPC.context<Context>().create();
 
const protectedProcedure = t.procedure.use((opts) => {
  const { ctx } = opts;
  if (!ctx.user) {
    throw new TRPCError({
      code: 'UNAUTHORIZED',
      message: 'You are not authorized',
    });
  }
 
  return opts.next({
    ctx: {
      // Infers that the `user` is non-nullable
      user: ctx.user,
    },
  });
});
 
const router = t.router({
  secret: protectedProcedure.query((opts) => opts.ctx.user),
});
 
{
  // ❌ this will return an error because there isn't the right context param
  const caller = router.createCaller({});
 
  const result = await caller.secret();
}
 
{
  // ✅ this will work because user property is present inside context param
  const authorizedCaller = router.createCaller({
    user: {
      id: 'KATT',
    },
  });
  const result = await authorizedCaller.secret();
          const result: {
    id: string;
}
}

ts
import { initTRPC, TRPCError } from '@trpc/server';
 
type Context = {
  user?: {
    id: string;
  };
};
const t = initTRPC.context<Context>().create();
 
const protectedProcedure = t.procedure.use((opts) => {
  const { ctx } = opts;
  if (!ctx.user) {
    throw new TRPCError({
      code: 'UNAUTHORIZED',
      message: 'You are not authorized',
    });
  }
 
  return opts.next({
    ctx: {
      // Infers that the `user` is non-nullable
      user: ctx.user,
    },
  });
});
 
const router = t.router({
  secret: protectedProcedure.query((opts) => opts.ctx.user),
});
 
{
  // ❌ this will return an error because there isn't the right context param
  const caller = router.createCaller({});
 
  const result = await caller.secret();
}
 
{
  // ✅ this will work because user property is present inside context param
  const authorizedCaller = router.createCaller({
    user: {
      id: 'KATT',
    },
  });
  const result = await authorizedCaller.secret();
          const result: {
    id: string;
}
}

Next.js API 端点的示例

提示

此示例展示了如何在 Next.js API 端点中使用调用者。tRPC 已经为您创建了 API 端点，因此此文件仅用于展示如何从另一个自定义端点调用过程。

ts
import { TRPCError } from '@trpc/server';
import { getHTTPStatusCodeFromError } from '@trpc/server/http';
import { appRouter } from '~/server/routers/_app';
import type { NextApiRequest, NextApiResponse } from 'next';
 
type ResponseData = {
  data?: {
    postTitle: string;
  };
  error?: {
    message: string;
  };
};
 
export default async (
  req: NextApiRequest,
  res: NextApiResponse<ResponseData>,
) => {
  /** We want to simulate an error, so we pick a post ID that does not exist in the database. */
  const postId = `this-id-does-not-exist-${Math.random()}`;
 
  const caller = appRouter.createCaller({});
 
  try {
    // the server-side call
    const postResult = await caller.post.byId({ id: postId });
 
    res.status(200).json({ data: { postTitle: postResult.title } });
  } catch (cause) {
    // If this a tRPC error, we can extract additional information.
    if (cause instanceof TRPCError) {
      // We can get the specific HTTP status code coming from tRPC (e.g. 404 for `NOT_FOUND`).
      const httpStatusCode = getHTTPStatusCodeFromError(cause);
 
      res.status(httpStatusCode).json({ error: { message: cause.message } });
      return;
    }
 
    // This is not a tRPC error, so we don't have specific information.
    res.status(500).json({
      error: { message: `Error while accessing post with ID ${postId}` },
    });
  }
};

ts
import { TRPCError } from '@trpc/server';
import { getHTTPStatusCodeFromError } from '@trpc/server/http';
import { appRouter } from '~/server/routers/_app';
import type { NextApiRequest, NextApiResponse } from 'next';
 
type ResponseData = {
  data?: {
    postTitle: string;
  };
  error?: {
    message: string;
  };
};
 
export default async (
  req: NextApiRequest,
  res: NextApiResponse<ResponseData>,
) => {
  /** We want to simulate an error, so we pick a post ID that does not exist in the database. */
  const postId = `this-id-does-not-exist-${Math.random()}`;
 
  const caller = appRouter.createCaller({});
 
  try {
    // the server-side call
    const postResult = await caller.post.byId({ id: postId });
 
    res.status(200).json({ data: { postTitle: postResult.title } });
  } catch (cause) {
    // If this a tRPC error, we can extract additional information.
    if (cause instanceof TRPCError) {
      // We can get the specific HTTP status code coming from tRPC (e.g. 404 for `NOT_FOUND`).
      const httpStatusCode = getHTTPStatusCodeFromError(cause);
 
      res.status(httpStatusCode).json({ error: { message: cause.message } });
      return;
    }
 
    // This is not a tRPC error, so we don't have specific information.
    res.status(500).json({
      error: { message: `Error while accessing post with ID ${postId}` },
    });
  }
};

错误处理

createFactoryCaller 和 createCaller 函数可以通过 onError 选项接受错误处理程序。这可用于抛出未包装在 TRPCError 中的错误，或以其他方式响应错误。传递给 createCallerFactory 的任何处理程序都将在传递给 createCaller 的处理程序之前被调用。处理程序的调用参数与错误格式化程序相同，但形状字段除外

ts
{
  ctx: unknown; // The request context
  error: TRPCError; // The TRPCError that was thrown
  path: string | undefined; // The path of the procedure that threw the error
  input: unknown; // The input that was passed to the procedure
  type: 'query' | 'mutation' | 'subscription' | 'unknown'; // The type of the procedure that threw the error
}

ts
{
  ctx: unknown; // The request context
  error: TRPCError; // The TRPCError that was thrown
  path: string | undefined; // The path of the procedure that threw the error
  input: unknown; // The input that was passed to the procedure
  type: 'query' | 'mutation' | 'subscription' | 'unknown'; // The type of the procedure that threw the error
}

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
const t = initTRPC
  .context<{
    foo?: 'bar';
  }>()
  .create();
 
const router = t.router({
  greeting: t.procedure.input(z.object({ name: z.string() })).query((opts) => {
    if (opts.input.name === 'invalid') {
      throw new Error('Invalid name');
    }
 
    return `Hello ${opts.input.name}`;
  }),
});
 
const caller = router.createCaller(
  {
    /* context */
  },
  {
    onError: (opts) => {
      console.error('An error occurred:', opts.error);
    },
  },
);
 
// The following will log "An error occurred: Error: Invalid name", and then throw a plain error
//  with the message "This is a custom error"
await caller.greeting({ name: 'invalid' });

ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
 
const t = initTRPC
  .context<{
    foo?: 'bar';
  }>()
  .create();
 
const router = t.router({
  greeting: t.procedure.input(z.object({ name: z.string() })).query((opts) => {
    if (opts.input.name === 'invalid') {
      throw new Error('Invalid name');
    }
 
    return `Hello ${opts.input.name}`;
  }),
});
 
const caller = router.createCaller(
  {
    /* context */
  },
  {
    onError: (opts) => {
      console.error('An error occurred:', opts.error);
    },
  },
);
 
// The following will log "An error occurred: Error: Invalid name", and then throw a plain error
//  with the message "This is a custom error"
await caller.greeting({ name: 'invalid' });

创建调用者​

基本示例​

集成测试中的示例用法​

router.createCaller()​

输入查询示例​

变异示例​

带有中间件的上下文示例​

Next.js API 端点的示例​

错误处理​