silk

Markdown based document-driven web API testing.

Write nice looking Markdown documentation (like this), and then run it using the silk command
Simple and robust Markdown API
Comes with real examples that you can copy (that are also part of the test suite for the project)

Learn more

(VIDEO) Watch the talk about Silk (with slides) or read about Silk in this blog post.

Markdown API

Tests are made up of documents written in Markdown.

# Group - Top level headings represent groups of requests
## GET /path - Second level headings represent a request
Code blocks with three back tics represent bodies
* Field: value - Lists describe headers and assertions
* ?param=value - Request parameters
=== seperators break requests from responses
Comments (starting with //) are ignored
Plain text is ignored to allow you to add documentation
Inline back tics are ignored and are available for formatting

Document structure

A document is made up of:

A request
=== seperator
Assertions

Requests

A request starts with ## and must have an HTTP method, and a path:

## METHOD /path

Examples include:

## GET /people

## POST /people/1/comments

## DELETE /people/1/comments/2

Request body (optional)

To specify a request body (for example for POST requests) use a codeblock using backtics (```):

```
{"name": "Silk", "release_year": 2016}
```

Request headers (optional)

You may specify request headers using lists (prefixed with *):

* Content-Type: "application/json"
* X-Custom-Header: "123"

Request parameters (optional)

Adding parameters to the path (like GET /path?q=something) can be tricky, especially when you consider escaping etc. To address this, Silk supports parameters like lists:

* ?param=value

The parameters will be correctly added to the URL path before the request is made.

Cookies

Setting cookies on a request can be done using the HTTP header pattern:

* Cookie: "key=value"

See asserting cookies.

Assertions

Following the === separator, you can specify assertions about the response. At a minimum, it is recommended that you assert the status code to ensure the request succeeded:

  * Status: 200

You may also specify response headers in the same format as request headers:

  * Content-Type: "application/json"
  * X-MyServer-Version: "v1.0"

If any of the headers do not match, the test will fail.

Asserting cookies

To assert that a cookie is present in a response, make a regex assertion against the Set-Cookie HTTP header:

  * Set-Cookie: /key=value/

All cookie strings are present in a single Set-Cookie seperated by a pipe character.

Validating data

You can optionally include a verbatim body using code blocks surrounded by three back tics. If the response body does not exactly match, the test will fail:

```
{"id": 1, "name": "Silk", "release_year": 2016}
```

You may also make any number of regex assertions against the body using the Body object:

  * Body: /Hello world/
  * Body: /This should be found too/
  * Body: /and this/

Alternatively, you can specify a list (using *) of data fields to assert accessible via the Data object:

  * Status: 201
  * Content-Type: "application/json"
  * Data.name: "Silk"
  * Data.release_year: 2016
  * Data.tags[0]: "testing"
  * Data.tags[1]: "markdown"
  * Data[0].name: "Mat"
  * Data[1].name: "David"

NOTE: Currenly this feature is only supported for JSON APIs.

Regex

Values may be regex, if they begin and end with a forward slash: /. The assertion will pass if the value (after being turned into a string) matches the regex.

  * Status: /^2.{2}$/
  * Content-Type: /application/json/

The above will assert that:

The status looks like 2xx, and
The Content-Type contains application/json

Command line

The silk command runs tests against an HTTP endpoint.

Usage:

silk -silk.url="{endpoint}" {testfiles}

{url} the endpoint URL (e.g. http://localhost:8080)
{testfiles} path to test files (e.g. ./testfiles)

Notes:

Omit trailing slash from url
{testfiles} can include a pattern (e.g. /path/*.silk.md)

Golang

Silk is written in Go and integrates seamlessly into existing testing tools and frameworks. Import the runner package and use RunGlob to match many test files:

package project_test

import (
  "testing"
  "github.com/matryer/silk/runner"
)

func TestAPIEndpoint(t *testing.T) {
  // start a server
  s := httptest.NewServer(yourHandler)
  defer s.Close()
  
  // run all test files
  runner.New(t, s.URL).RunGlob(filepath.Glob("../testfiles/failure/*.silk.md"))
}

See the documentation for the silk/runner package

Credit

Special thanks to @dahernan for his contributions and criticisms of Silk
Silk logo by Chris Ryer

craftgear / silk