easymock

Easy to use mock server that supports templates and routes.

Usage no npm install needed!

<script type="module">
  import easymock from 'https://cdn.skypack.dev/easymock';
</script>

README

EasyMock Server

Usage

    $ npm install -g easymock
    $ easymock

Files

All files from the running folder are present as static files. So place anything in there and it is accessible with GET filename.

Differentiating GET/POST/PUT/PATCH/DELETE

If you want to use advanced serving features like GET/POST/PUT/PATCH/DELETE or templates in json, provide files like in the example below:

    GET /items/1 => items/1_get.json
    POST /items/1 => items/1_post.json
    ...

config.json

If you want to configure routes, proxy or lag, create a config.json file which looks kind of like this:

    {
      "simulated-lag": 1000,
      "cors": false,
      "jsonp": false,
      "proxy": {
        "server": "http://yourrealapi.com",
        "default": false,
        "calls": {
          "/items/1": { "get": true, "post": false },
          "/items": false
        }
      },
      "variables": {
        "name": "My name"
      },
      "routes": [
        "/user/:userid",
        "/user/:userid/profile",
        "/user/:userid/inbox/:messageid"
      ]
    }

Simulating lag in responses

To add the same lag to all responses, set simulated-lag to a number.

{
  "simulated-lag": 1000
}

If you want a random lag in responses, like in a real-world scenario, set simulated-lag-min and simulated-lag-max instead of simulated-lag. If simulated-lag is set, it will take precedence over simulated-lag-min and -max.

Changing the simulated lag based on the path

For more fine-grained control over lag in responses, specify an object for simulated-lag, as in the following example:

{
  "simulated-lag": {
    "default": 500,
    "paths": [
      {
        "match": "^/usersquot;,
        "lag": 1000
      },
      {
        "match": "^/users/.*",
        "lag": 2000
      },
      {
        "match": "no-lag",
        "lag": 0
      }
    ]
  }
}

Each "match" value is turned into a regular expression (using new RegExp) and matched against the request path (which excludes the query string). The first match found in the "paths" array is the one used, so be careful with the order.

Variables

Variables that you define in your config.json can be used in files that have the _get/_post/... extension. As well you can use them in your templates.

Nested variables support: #{name_#{lang}} will resolve to #{name_de} for #{lang} = 'de' (if given as GET or POST parameter for example).

Following variables are available by default:

  • #{HOST} -> Requested hostname (and port) of the request. For example localhost:3000 or 127.0.0.1
  • #{QUERY_STRING} -> Complete query string of the request. For example foo=bar or a=b&c=d

Example to use variables. item_get.json:

    { "user_name": "#{name}", "image": "http://#{HOST}/img.jpg"}

This will return:

    { "user_name": "#{user_name", "image": "http://localhost/img.jpg"}

GET query and POST body fields as Variables

Any field given in GET or POST can be used like other variables.

    Example: GET /search?q=test

Will provide you with a usable #{q} in your json file.

Header fields as variables

Any header can be used as a variable. For example the header Accept-Language can be accessed via #{HEADER_ACCEPT_LANGUAGE}.

Routes

The routes defined in the config.json will get mapped to one corresponding file in which the given name will be available as a variable.

With the above config.json a call to GET /user/1234 would get mapped to the file: /user/userid_get.json. Inside that file one could write:

{ "id": #{userid} }

If this is the file, the result would be { "userid": 1234 }

Templates

If you have items that are used over and over again, you can make templates for them and reuse the same template.

For that create a folder _templates and in it place for example a file object.json:

    { "name": "my object" }

Then you can refer this template out of another file like items_get.json:

    [ "{{object}}", "{{object}}", "{{object}}", "{{object}}" ]

This will return a array with four times the object from the template.

Parameters

You can even use parameters. For example you have a template Object.json:

     {
        "name": "Item #{_1}",
        "image": "#{server}/img/img_#{_2}.jpg",
        "active": #{_3}
      }

And then a api object called items_get.json:

      [
        "{{Object(1,one,true)}}",
        "{{Object(2,two,false)}}",
        "{{Object(3,three,true)}}"
      ]

You will receive the following response:

      [
         {
            "name":"Item 1",
            "image":"http://server.com/img/img_one.jpg",
            "active":true
         },
         {
            "name":"Item 2",
            "image":"http://server.com/img/img_two.jpg",
            "active":false
         },
         {
            "name":"Item 3",
            "image":"http://server.com/img/img_three.jpg",
            "active":true
         }
      ]

Response headers

You can specify the status code for the response with @status and add headers with @header. The following example is for doing a redirect response.

< @status 301
< @header Location: http://www.cyberagent.co.jp

Will respond with:

HTTP/1.1 301 Moved Permanently
x-powered-by: Express
location: http://www.cyberagent.co.jp
content-type: text/html; charset=utf-8
content-length: 0
date: Tue, 12 Mar 2013 08:21:39 GMT
connection: close

Documentation

easymock automatically documents the API it represents. This documentation can be extended by adding additional information like description, input info and output info to the json file. This is an example on how to do that for example in test_post.json:

# This is some documentation
# This call creates an object
> @param name
> @param description (optional)
> @body {
> @body   "name": "Nobody"
> @body }
< @status 200
< @header Content-Type: application/json
{
  "id": 1234,
  "name": "your name",
  "description": "your description"
}

Explanation:

  • # Is general information about the call.
  • > About the request to the API.
  • < About the response from the API.
  • Everything afterwards is the response body.

To add some general information in the documentation, add a file _documentation/index.md. That one will be shown at the top of the documented calls.

Logging

All requests get logged and can be inspected. You can do so at http://localhost:3000/_logs/.

CORS and JSONP

Can be enabled by setting either "jsonp" or "cors" or both to true in the config.json.

Errors

Easymock can return errors defined in the documentation. the config.json set "error-rate": 0.5, to have a 50% error rate. So one out of 2 calls in average will return an error. To specify an error, first add a error json file in _errors. For example "_errors/not_authenticated.json":

< @status 401
{
  "error": "Authentication required"
}

In the mock file add an error like the following (example user.json):

< @error sample
< @error sample2
< @error sample3 0.5

If there are multiple errors like above, it will randomly select one. By default it uses the error-rate specified in the config.json. A specific error rate for each error can be set by adding the error rate as shown above.

The name after @error indicates the file name. "@error sample" will serve "_errors/sample.json".

General errors

For errors that can occur on any call, set up the config.json as follows:

{
  "error-rate": 1,
  "errors" : ["general"]
}

Or to have specific error rates on each general error:

{
  "error-rate": 0,
  "errors" : [
    {
      "name": "general",
      "rate": 0.1
    },{
      "name": "general2",
      "rate": 0.3
    }
  ]
}

Run tests

make tests

License

(MIT License)

Copyright (C) 2012 CyberAgent

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.