How to Use the Command 'cotton' (with Examples)

Cotton is a versatile tool designed for running markdown test specifications efficiently. It allows developers to validate API endpoints and other functionalities defined within markdown files, ensuring that the documentation stays up-to-date and functions as expected. With its array of options, Cotton provides flexibility and control over the test execution environment, making it a valuable asset in the software development and testing pipeline.

Use Case 1: Use a Specific Base URL

Code:

cotton -u base_url path/to/file.md

Motivation:

In many scenarios, especially during the development of APIs or web applications, it’s important to test your services against different environments. These environments could be local development servers, staging environments, or even production. By using a specific base URL, you can direct the test specification runner to evaluate the markdown tests against a particular environment. This functionality ensures that the code behaves correctly under various conditions and configurations.

Explanation:

• cotton: This is the command you are executing. It invokes the Cotton test runner.

• -u base_url: The -u flag stands for ‘URL’. The base_url argument specifies the root URL that Cotton will use as the base for resolving relative URLs within the markdown file. This allows you to tailor the execution to a specific server or environment.

• path/to/file.md: This is the path to the markdown file containing the test specifications you want to execute. Cotton will analyze this file to locate any specified commands or syntax that require validation.

Example Output:

When you run the command, you might see an output that details the tests that are executed along with their results, such as:

Running tests from file: path/to/file.md
Test 1: GET /api/resource - Passed
Test 2: POST /api/resource - Passed
Tests completed: 2 passed, 0 failed

Use Case 2: Disable Certificate Verification (Insecure Mode)

Code:

cotton -u base_url -i path/to/file.md

Motivation:

Sometimes, particularly in development or testing phases, you may be dealing with servers that are using self-signed certificates or no certificates at all. By default, Cotton, like many test runners, will verify SSL certificates to ensure secure connections. In instances where this is not feasible or necessary, such as when you’re running tests internally or in a secure and closed network, you can disable this verification. Disabling certificate verification allows tests to proceed without errors related to SSL, providing a workaround for environments not configured with valid certificates.

Explanation:

• -i: This option tells Cotton to operate in “insecure mode”. It disables SSL certificate verification. This is crucial when working with APIs over HTTPS in environments that do not have properly configured or trusted certificates.

Example Output:

The output might be similar to a normal test run but could include a warning about insecure operations:

Running tests from file: path/to/file.md
Warning: Certificate verification is disabled. Connection is insecure.
Test 1: GET /api/resource - Passed
Test 2: POST /api/resource - Passed
Tests completed: 2 passed, 0 failed

Use Case 3: Stop Running When a Test Fails

Code:

cotton -u base_url -s path/to/file.md

Motivation:

In many testing scenarios, it may be undesirable or inefficient to continue running subsequent tests once a failure has been detected. Early termination upon encountering a test failure can be particularly useful during CI/CD pipelines, where identifying and fixing issues quickly is paramount. This approach helps developers focus on resolving the first encountered issue before addressing downstream tests that may also fail for related reasons.

Explanation:

• -s: The stop-on-fail option. By including -s, Cotton will halt execution as soon as it encounters the first test that fails. This can save time and resources, particularly in extensive test suites where later failures are likely resultant of the first one.

Example Output:

The expected output will show when and which test causes the runner to stop:

Running tests from file: path/to/file.md
Test 1: GET /api/resource - Passed
Test 2: POST /api/resource - Failed
Execution stopped due to test failure at Test 2.

Conclusion:

Cotton is a powerful tool that supports various configurations for running markdown tests. By tailoring the execution environment and behavior through different flags and options, developers can streamline their testing procedures. Whether adjusting the base URL for environment-specific testing, disabling SSL verification for convenience in secure settings, or optimizing the testing process to stop on failures, Cotton provides a flexible solution tailored to developer needs.