Oclif RunCommand Vitest Test Fails With Command X Not Found

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Introduction

As a developer, you're likely familiar with the challenges of testing command-line interfaces (CLI) using various testing frameworks. In this article, we'll delve into a specific issue that arises when using Oclif with Vitest, where tests fail with a "Command X not found" error. We'll explore the possible causes and provide solutions to help you overcome this hurdle.

Understanding the Issue

When running tests with Vitest, you might encounter an error message indicating that a specific command is not found. This issue is particularly puzzling when the same tests pass with Jest. The problem lies in the way Vitest handles mocking, which can lead to unexpected behavior.

The Role of Mocking in Testing

Mocking is a crucial aspect of testing, allowing you to isolate dependencies and focus on the behavior of your code. In the context of Oclif and Vitest, mocking is used to simulate the behavior of external commands. However, the mocking mechanism in Vitest can sometimes lead to issues, such as the "Command X not found" error.

The Structure of Your Code

Let's take a closer look at the structure of your code:

src/
  commands/
    foo-cmd.ts
    tests/
      foo-cmd.test.ts

In this example, you have a foo-cmd.ts file containing the implementation of the foo command, and a foo-cmd.test.ts file containing the tests for that command.

The Issue with Vitest

When running tests with Vitest, you might encounter an error message similar to this:

Command 'foo' not found

This error occurs because Vitest is unable to find the foo command, even though it's defined in the foo-cmd.ts file.

Possible Causes

There are several possible causes for this issue:

  1. Incorrect Mocking: Vitest's mocking mechanism might not be properly configured, leading to incorrect behavior.
  2. Missing Dependencies: The foo-cmd.ts file might be missing dependencies required by the foo command.
  3. Incorrect Command Registration: The foo command might not be properly registered in the Oclif CLI.

Solutions

To resolve the "Command X not found" error, try the following solutions:

1. Verify Mocking Configuration

Ensure that your mocking configuration is correct. You can do this by checking the vitest.config.js file and verifying that the mocking options are properly set.

module.exports = {
  // ...
  testEnvironment: 'node',
  testTimeout: 10000,
  setupFilesAfterEnv: ['<rootDir>/tests/setup.js'],
  // ...
};

2. Check Dependencies

Verify that the foo-cmd.ts file has all the required dependencies. You can do this by checking the package.json file and ensuring that all dependencies are installed.

{
  "name": "my-cli",
  "version": "1.0.0",
  "scripts": {
    "test": "vitest"
  },
  "dependencies": {
    "@oclif/command": "^.0.0",
    "@oclif/core": "^1.0.0"
  },
  "devDependencies": {
    "@vitest/core": "^0.20.0",
    "@vitest/runner": "^0.20.0"
  }
}

3. Register Commands Correctly

Ensure that the foo command is properly registered in the Oclif CLI. You can do this by checking the src/index.ts file and verifying that the command is registered correctly.

import { Command } from '@oclif/command';
import { fooCmd } from './commands/foo-cmd';

export default class MyCLI extends Command {
static description = 'My CLI';


static examples = [
'$ my-cli foo',
];


static flags = {
// ...
};


static args = [
// ...
];


async run() {
// ...
}
}

4. Update Vitest Configuration

Update the Vitest configuration to use the --mocks option. This option allows you to specify custom mocking behavior.

module.exports = {
  // ...
  testEnvironment: 'node',
  testTimeout: 10000,
  setupFilesAfterEnv: ['<rootDir>/tests/setup.js'],
  testMatch: ['**/*.test.ts'],
  testPathIgnorePatterns: ['/node_modules/'],
  // ...
  testEnvironmentOptions: {
    // ...
    mocks: {
      './commands/foo-cmd': () => ({
        foo: () => {
          // Custom mocking behavior
        },
      }),
    },
  },
};

Conclusion

The "Command X not found" error when running tests with Vitest can be frustrating, but it's often a result of incorrect mocking or missing dependencies. By following the solutions outlined in this article, you should be able to resolve the issue and get your tests running smoothly.

Best Practices

To avoid this issue in the future, follow these best practices:

  • Verify that your mocking configuration is correct.
  • Ensure that all dependencies are installed and up-to-date.
  • Register commands correctly in the Oclif CLI.
  • Update the Vitest configuration to use the --mocks option.

Introduction

In our previous article, we explored the issue of "Command X not found" errors when running tests with Vitest. We discussed the possible causes and provided solutions to help you overcome this hurdle. In this article, we'll answer some frequently asked questions related to this issue.

Q: What is the difference between Jest and Vitest?

A: Jest and Vitest are both testing frameworks, but they have different design goals and philosophies. Jest is a more mature and widely-used testing framework, while Vitest is a newer, more lightweight alternative. Vitest is designed to be faster and more efficient than Jest, but it may not support all the features and plugins that Jest offers.

Q: Why do I get a "Command X not found" error when running tests with Vitest?

A: The "Command X not found" error occurs when Vitest is unable to find the command you're trying to test. This can be due to incorrect mocking, missing dependencies, or incorrect command registration.

Q: How do I configure Vitest to use custom mocking behavior?

A: You can configure Vitest to use custom mocking behavior by updating the vitest.config.js file. Add the testEnvironmentOptions property and set the mocks option to specify custom mocking behavior.

module.exports = {
  // ...
  testEnvironment: 'node',
  testTimeout: 10000,
  setupFilesAfterEnv: ['<rootDir>/tests/setup.js'],
  testMatch: ['**/*.test.ts'],
  testPathIgnorePatterns: ['/node_modules/'],
  // ...
  testEnvironmentOptions: {
    // ...
    mocks: {
      './commands/foo-cmd': () => ({
        foo: () => {
          // Custom mocking behavior
        },
      }),
    },
  },
};

Q: How do I register commands correctly in the Oclif CLI?

A: To register commands correctly in the Oclif CLI, you need to create a src/index.ts file and define the command registration logic. You can use the oclif library to register commands.

import { Command } from '@oclif/command';
import { fooCmd } from './commands/foo-cmd';

export default class MyCLI extends Command {
static description = 'My CLI';


static examples = [
'$ my-cli foo',
];


static flags = {
// ...
};


static args = [
// ...
];


async run() {
// ...
}
}

Q: How do I troubleshoot the "Command X not found" error?

A: To troubleshoot the "Command X not found" error, you can try the following steps:

  1. Verify that your mocking configuration is correct.
  2. Ensure that all dependencies are installed and up-to-date.
  3. Register commands correctly in the Oclif CLI.
  4. Update the Vitest configuration to use the --mocks option.

Q: Can I use both Jest and Vitest in the same project?

A: Yes, you can use both Jest andest in the same project. However, you'll need to configure both testing frameworks separately and ensure that they don't conflict with each other.

Conclusion

In this article, we answered some frequently asked questions related to the "Command X not found" error when running tests with Vitest. We provided solutions and best practices to help you troubleshoot and resolve this issue. By following these guidelines, you'll be able to write high-quality tests that accurately reflect the behavior of your code.

Best Practices

To avoid the "Command X not found" error in the future, follow these best practices:

  • Verify that your mocking configuration is correct.
  • Ensure that all dependencies are installed and up-to-date.
  • Register commands correctly in the Oclif CLI.
  • Update the Vitest configuration to use the --mocks option.
  • Use both Jest and Vitest in the same project with caution and ensure that they don't conflict with each other.