serverless/docs/guides/testing.md

Read this on the main serverless docs site

Testing

Serverless Framework supports defining and running integration tests against lambdas with HTTP integrations. To get started, assuming we have the default configuration in from the enterprise-template, you can define a test for it as follows with a serverless.test.yml file:

- name: hello endpoint returns 200
  endpoint:
    function: hello
  response:
    status: 200

Then, when you run sls test (your function must already have been deployed) it will make an HTTP request against the hello function and pass if the response has a status code of 200:

$ sls test
Serverless Enterprise: Test Results:

  Summary --------------------------------------------------

  passed - POST hello - hello endpoint returns 200

Serverless Enterprise: Test Summary: 1 passed, 0 failed

If we add a test like this which requires the body to be JSON encoded and contain a key called foo with the value bar.

- name: hello endpoint returns 200
  endpoint:
    function: hello
  response:
    body:
      foo: bar

Then when we run sls test we get the details of the failure:

$ sls test
Serverless Enterprise: Test Results:

  Summary --------------------------------------------------

  passed - POST hello - hello endpoint returns 200
  failed - POST hello - hello endpoint returns 2000

  Details --------------------------------------------------

  1) Failed - hello endpoint returns 200
     status: 200
     headers: (TRUNCATED)
     expected: body = {
       "foo": "bar"
     }
     received: body  = {
       "message": (TRUNCATED),
       "input": (TRUNCATED),
     }

Serverless Enterprise: Test Summary: 1 passed, 1 failed

serverless.test.yml specification

The specification file must be an array of objects. Each test is an object in that array. Here is a config file that uses all the options:

- name: hello endpoint returns success # the name of the test. used for running a specific test & in CLI output
  endpoint: # this is used to specify which HTTP endpoint / lambda to test against
    # specifying only the function name only works if the function has only one HTTP endpoint and
    # a specific path & method (i.e. not ANY or {parameterizedUrls})
    function: hello
  response: true # setting response to true is equivalent to setting it to {status: 200}
  request: # this specifies the request to send
    headers: # An object mapping to be used as headers on the request
      Foo: bar
    body: 'foobar' # string literal bodies are used as-is
- name: "hello endpoint returns 'foobar'"
  endpoint:
    # if specifying both method & path, function is optional
    method: POST
    path: /hello
  response:
    body: 'foobar' # setting body to a string literal checks that the response text matches it exactly
- name: hello endpoint returns ok with json request
  endpoint:
    function: hello
  response: true
  request:
    body: # setting body to an object json encodes it & adds the correct content-type header
      foo: bar
      blah: baz
- name: hello endpoint returns success with a form request
  endpoint:
    function: hello
  response: true
  request:
    form: # setting form encodes to a query param, i.e.: ?foo=bar&blah=baz
      foo: bar
      blah: baz
- name: hello endpoint returns success with a text request
  endpoint:
    function: hello
  response: true
  request:
    body: 'foobar' # setting body to a string uses it with out any changes

Options

There are 2 options to allow you to avoid running your entire test suite:

• --function - only run tests for the function specified. This requires that you've set endpoint.function
• --name - only run the test with the specified name