vitest actions

[runic mantle]

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Astro’s official documentation does not currently provide a dedicated template or example for testing actions (defined with astro:actions) using Vitest, nor does it describe how to mock middleware in this context. The available testing guidance focuses on component testing with Vitest and the experimental Container API, not on backend logic or middleware for actions.

What the Docs Cover

• Component Testing with Vitest: You can use Vitest with Astro by configuring it with getViteConfig() and test components using the Container API. Example:

  import { experimental_AstroContainer as AstroContainer } from 'astro/container';
  import { expect, test } from 'vitest';
  import Card from '../src/components/Card.astro';
  
  test('Card with slots', async () => {
    const container = await AstroContainer.create();
    const result = await container.renderToString(Card, {
      slots: { default: 'Card content' },
    });
    expect(result).toContain('This is a card');
    expect(result).toContain('Card content');
  });
  

  Testing guide

• Actions: Actions are defined in src/actions/index.ts and can be called from client code, Astro components, or server endpoints. There is no mention of direct unit testing or mocking middleware for actions in the documentation.
  Actions guide

What’s Missing

• No Official Example for Testing Actions with Vitest: There is no documented approach for writing Vitest tests for actions (e.g., calling action handlers directly in a test).
• No Guidance on Mocking Middleware: The documentation does not describe how to mock or bypass middleware when testing actions.

Suggested Approach (Based on Docs)

• You can test your action handler functions directly by importing them in your test files, as they are just JavaScript functions. However, you will need to manually mock any context or dependencies they require.
• For middleware, since Astro’s middleware is designed to run in the server environment, you would need to mock the context object and any methods used by your middleware in your tests.

Example: Testing an Action Handler (Manual Approach)

Suppose you have an action like this:

// src/actions/index.ts
import { defineAction } from 'astro:actions';
import { z } from 'astro:schema';

export const server = {
  getGreeting: defineAction({
    input: z.object({ name: z.string() }),
    handler: async (input) => {
      return `Hello, ${input.name}!`;
    }
  })
};

You could test the handler directly in Vitest:

// tests/getGreeting.test.js
import { server } from '../src/actions/index';

test('getGreeting returns correct greeting', async () => {
  const result = await server.getGreeting.handler({ name: 'Astro' }, {});
  expect(result).toBe('Hello, Astro!');
});

Example: Mocking Middleware (Manual Approach)

If your action handler depends on context.locals or similar, you can pass a mock object:

test('getGreeting with context', async () => {
  const mockContext = { locals: { user: 'test-user' } };
  const result = await server.getGreeting.handler({ name: 'Astro' }, mockContext);
  expect(result).toBe('Hello, Astro!');
});

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Summary:
There is no official template or built-in support for testing actions or mocking middleware in Astro with Vitest. You can, however, test action handlers as plain functions and manually mock any required context. For more advanced integration or middleware testing, you would need to set up your own mocks and test harnesses, as the documentation does not provide further guidance on this topic Testing guide Actions guide.

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@static tendon Kapa.ai is still learning and improving, please let me know how I did by reacting below.

[static tendon]

@runic mantle i get this error

Error: Failed to load url astro:actions (resolved id: astro:actions) i

[runic mantle]

Let me check the knowledge base for you again. One moment! :books:

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The error message

Error: Failed to load url astro:actions (resolved id: astro:actions)

typically means that Astro could not import the astro:actions module. According to the documentation, this can happen if the import path is incorrect, the file does not exist, or there is a typo in the path. Another common cause is importing a type without specifying it as a type import in TypeScript Could not import file.

What you should check:

1. Correct Import Path:
   Make sure you are importing from astro:actions exactly as shown in the documentation:

   import { actions } from 'astro:actions';
   

2. Astro Version:
   The astro:actions module was added in [email protected]. Ensure your project is using Astro version 4.15.0 or later Actions API Reference.

3. Actions File Exists:
   You must have a src/actions/index.ts file exporting a server object with your actions. If this file is missing or misconfigured, Astro cannot load your actions Basic usage.

4. Restart the Dev Server:
   Sometimes, Astro needs to be restarted to recognize new or changed actions. Stop and restart your dev server after making changes actions.

5. TypeScript Type Imports:
   If you are importing types from astro:actions, use the import type syntax to avoid import errors.

If you have checked all of the above and the error persists, please provide more details about your setup or the code that triggers the error.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: