@hectorjs/stub-backend

Releases documentation

Description

The aim of this project is to mock the backend services based on a JSON configuration. You don't need to do anything programmatically.

This library gives you the chance to focus in your code reducing the amount of work mocking the dependencies. :smile:

hjs-cli

There is a command line to generate default scenarios using GET, POST or PUT methods, among others ones.

I suggest you to have a look and give it a try. It will reduce the time to mock the services, which is one of the main goals of this library.

Have a look @hectorjs/stub-cli.

Installation

npm i @hectorjs/stub-backend --save-dev

Set hjs command

:warning: (this step is not necessary if you have the cli globally installed)

Include hjs command in your package.json as a script:

"scripts":{
  "hjs":"hjs"
}

Note: You can check it executing npm run hjs -- --version in your terminal.

Structure

Packages

Create a folder named _hjs in the package root directory. Under that folder, create a resources folder and add a couple of json files, which you can name as you wish. You can create subfolders under resources as well.

 package.json
 _hjs
 |
  -resources
   |
    - *.json
    - *.json
    - subfolder
      |
       - *.json
       - *.json

Files structure

Each file must contain a json object. The first key indicates the method of the request and it must have a "_" as a prefix. For example:

{
  "_get":{        
  },
  "_post":{       
  }    
}

Methods: _get, _head, _post, _put, _delete, _options, _trace, _patch.

Path level

The next level indicates the endpoint to call. The path is written as the following examples:

• /customers/names

• /customers/{id}/name

• /countries/{id}/product

• /countries/{id}/population?town={param1}&postcode={param2}

  {
    "_[method]":{
       "/customers/names":[
         {}
       ],
       "/customers/{id}/name":[
         {}
       ],
       "/countries/{id}/product":[
         {}
       ],
       "/countries/{id}/population?town={param1}&postcode={param2}":[
         {}
       ]
    }
  }

NOTE: id, param1 or param2 can be named as you want. However, they must be unique.

Scenarios

This level indicates possible scenarios based on different parameters.

Index:

• _req
• _res

Each scenario contains two sections _req (request) and _res (response) where we place the properties in relation to the request and response.

:warning: Both levels are mandatory in each scenario. Even if you don't want to add anything in the request, you must add an empty _req.

_req

Basically, the scenario which is going to be selected to provide the response is the one which has more matches in the _req section with the real request.

"/customers/{id1}/data/{id2}" : [
  {
    "_req":{
    }
  },
  {
    "_req":{
    }
  }
]

You can have the following properties for matching the request:

• _[id]
• _headers
• _cookies
• _body
• _bodyPaths
• _excludeBodyFields

_[id]

Identifiers of a path. For example, given a path /customers/{id1}/data/{id2}, it should be structured as follows:

"/customers/{id1}/data/{id2}" : [
  {
    "_req":{
      "_id1": "chris",
      "_id2": "1"
    }
  },
  {
    "_req":{
      "_id1": "Fran",
      "_id2": "2"
    }
  }
]

It will choose the first scenario when id1 is Chris and id2 is 1 and the second one when id1 is Fran and id2 is 2.

cli hjs generate get customers/{id1}/data/{id2}

NOTE: If you include * as a value, it will work as a wildcard.

For example, given the example above when the request is /customers/chris/data/*, it will choose the first scenario.

_headers

There are two different ways to match by headers:

Match by key

It is an array of header keys. Basically, it will match if the request contains all the headers in the array.

"/customers/{id}/data" : [
  {
    "_req":{
      "_headers": ["authorization", "client_Id"]
    }
  }
]

cli hjs generate get customers/{id}/data --headers authorization,client_Id

Match by key or match by value

Header can match key or values for specific fields also where required.

"/customers/{id}/data" : [
  {
    "_req":{
      "_headers": ["authorization", {"client_Id": "expected_value"}]
    }
  }
]

Match by key and value

It is an array of objects. The key is the header name and the value is the header value. You can see it in the next example:

"/customers/{id}/data" : [
  {
    "_req":{
      "_headers": {
        "authorization":"1234",
        "client_Id":"121"
        }
    }
  }
]

cli hjs generate get customers/{id}/data --headers authorization,client_Id

Set the key value headers manually.

NOTE: If the scenario does not contain any headers section, the service won't check anything. Capital letters are not allow in headers section.

Content-type

By default all the requests are based on json.

If you include in your header the following options:

1. multipart/form-data

The values keyName=ValueName will be matching in the body section like:

{
  _body:{
    [keyName]:[ValueName]
  }  
}

2. application/x-www-form-urlencoded

The values keyName=ValueName will be matching in the body section like:

{
  _body:{
    [keyName]:[ValueName]
  }  
}

_cookies

There are two different ways to match the cookies:

Match by key

It is an array of cookies keys. Basically, it will match if the request contains all the cookies in the array.

"/customers/{id}/data" : [
  {
    "_req":{
      "_cookies": ["Universal", "sec"]
    }
  }
]

cli: hjs generate get customers/{id}/data --cookies Universal,sec

Match by key-value

It is an array of objects. The key is the header name and the value is the header value. You can see in the next example:

"/customers/{id}/data" : [
  {
    "_req": {
      "_cookies": {
        "Universal":"123", 
        "sec":"1232"
        }
    }
  }
]

NOTE: If the scenario does not contain any cookies section, the service won't check anything.

cli hjs generate get customers/{id}/data --cookies authorization,client_Id

Set the key value cookies manually.

NOTE: If the scenario does not contain any cookies section, the service won't check anything.

_body

You might want to match the body for some methods like post, put or delete. _body object is the request body for a specific scenario. It will check the entire object.

"/customers/{id}/data" : [
  {
    "_req": {
      "_body": {
        "dummyRequestBody1": "anyValue"   
      }
    }
    "_description": "secure scenario given an authorization header"
  }
]

Note: If any field is missed, the scenario will not be matched.

_bodyPaths

Instead of matching the entire body of a request, you can verify verify just a specific fields or objects using _bodyPaths.

bodyPaths is a key value object where the key is the jsonPath and the value is the object to match.

Example:

"/customers/{id}/data" : [
  {
    "_req": {
      "_bodyPaths": {
        "$.heroes": { "name": "superman"}, 
        "$.cities[0].name": "madrid"
      }
    },
    "_res":{
    },
    "_description":"secure scenario given an authorization header"
  }
]

_bodyPaths can be an array also as an option to validate a field or value.

"/customers/{id}/data" : [
  {
    "_req": {
      "_bodyPaths": [
        "$.heroes": { "name": "superman"}, 
        "$.cities[0].name"
      ]
    },
    "_res":{
    },
    "_description":"secure scenario given an authorization header"
  }
]

Also, you can include a regex to check different values. Example:

"/customers/{id}/data" : [
  {
    "_req": {
      "_bodyPaths": {
        "$.id": "^[v].*[3]$"
      }
    },
    "_res":{
    }
  }
]

Above expresion will check id which starts with v and ends with 3

NOTE: bodyPaths and body section can not be at the same time.

_excludeBodyFields

Whenever you need to exclude the comparation of some fields (timestamps for example) or objects from the _body or bodyPaths, You can do it adding an array of json paths (you can exlude multiple fields or objects).

"_excludeBodyFields": [ "$.value1.value2[0]", "$.value3"]

Note: If you have any doubt about how to do the path, you can have a look to jsonPath libray which is used in the project.

Note: The library will not exclude any field or object if _excludeBodyFields is not added.

_res

This section create a response when a scenario is matched.

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
    }
  },
  {
    "_res":{
    }
  }
]

You can have the following properties in the response:

• _status
• _headers
• _cookies
• _delay
• _body

_status

You can set your own status.

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
      "_status": 400
    }
  },
  {
    "_res":{
      "_status": 404
    }
  }
]

cli: hjs generate get customers/{id}/data/{id2} --status 404

NOTE: if _status doesn't exist, it will return 200.

_headers

You have the option to set headers in the response just by key or key-value.

by key

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
      "_headers": ["key-header-1", "key-header-2"]
    }
  }
]

NOTE: the value of each key will be generated with default values.

by key-value

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
      "_headers": {
        "key-header-1": "custom-value-1",
        "key-header-2": "custom-value-2"
      }
    }
  }
]

_cookies

You have the option to set cookies in the response just by key or key-value.

by key

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
      "_cookies": ["key-cookie-1", "key-cookie-2"]
    }
  }
]

NOTE: the value of each key will be generated with default values.

by key-value

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
      "_cookies": {
        "key-cookie-1": "custom-value-1",
        "key-cookie-2": "custom-value-2"
      }
    }
  }
]

_delay

It is adding a delay in milliseconds to the response.

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
      "_delay": 10000
    }
  }
]

cli: hjs generate get customers/{id}/data --delay 1000

_body

This section contains the response for a given request.

"/customers/{id1}/data/{id2}" : [
  {
    "_res":{
      "_body": {
        "dummyResponse1": "anyValue"
      }
    }
  },
  {
    "_res":{
      "_body": {
        "dummyResponse2": "anyValue"
      }
    }
  }
]

_description

Brief explanation about the scenario.

"/customers/{id}/data" : [
  {
    "_req": {
      
    },
    "_res":{

    },
    "_description":"secure scenario given an authorization header"
  }
]

cli: hjs generate get customers/{id}/data --description "Hello world"

Example

Below, we have a example:

{
  "_get": {
    "/stories/{id}/person$": [
      {
        "_req":{
          "_id": "Nathan",
          "_headers": []
        },
        "_res":{
          "_body": {
            "name": "Nathan"
          }
        },
        "_description": "Get person details related to  Nathan without authentication"
      },
      {
        "_req":{
          "_id": "Lucas",
          "_headers": []
        },
        "_res":{
          "_status": 304,
          "_body": {
            "name": "Nathan"
          }
        },
        "_description": "There won't be any response    because the status is 304"
      },
      {
        "_req":{
          "_id": "mark",
          "_headers": ["authorization"],
          "_cookies": []
        },
        "_res":{
          "_body": {
            "name": "Mark"
          }
        },
        "_description": "Get person details related to Mark     with authentication"
      }
    ]
  },
  "_post" :{
      "/stories/{id}/budget": [
        {
          "_req":{
            "_id": "Nathan",
            "_headers": ["Client_id"],
            "_cookies": [
              "session-id",
              "key-id"
            ],
            "_body": {
              "anyData": "anyData"
            },
          },
          "_res":{
            "_body": {
              "name": "Nathan"
            }
          },
          "_description": "Get budget details related to  Nathan with authentication"
        }
      ]
  }
}

If you want to test it, copy the previous example and paste it in one of the json files. Then execute the following command:

node .\\node_modules\\@hectorjs\\stub-backend\\lib\\app.js

or with cli

hjs start

The service will be running in the port 3005 waiting for a request.

Make a request:

curl http://localhost:3005/stories/nathan/person

The response will be like this:

{
    "name": "Nathan"
}

Advance options

• Xml
• Avoid delays
• Banner
• Retry opts
• Same request different response
• Config file

Xml

This section is in progress. At this moment, the user can response a xml setting the _xml flag to true like the following scenario:

{
 "_post" :{
    "/stories/{id}/budget": [
      {
        "_req":{
          "_id": "Nathan",
          "_body": "<xml><book><title>The lyon king</title></book></xml>",
        },
        "_res":{
          "_xml": true,
          "_body": "<xml><book><title>Flash</title></book></xml>"
        }
      }
    ]
  }
}

Avoid Delays

You have the option to avoid all the delays. By default, it will execute the mocks with delays, but you can add --no_delay arg and the application won't add delays.

Example: hjs start --no_delay

Banner

You can use your own banner instead of hectorjs one. You just need to add a file called .hjs.banner.js in the roor of your project. Have a look to the following example:

module.exports = function(){
    console.log('\x1b[32m%s\x1b[0m', 'My custom message');
}

NOTE: you can add a config file using the following command: For an existing project:

• hjs config --banner have upper version 0.24.0 hectorjs/stub-cli. For a new mock service:
• hjs new --banner create project with a custom banner.

Retry opts

A possible scenario including retry options could be:

{
  "_get": {
    "/customers/{id}": [{
        "_req": {
          "_id": "2"
        },
        "_retry": 2,
        "_res": {
          "_body": {
            "any": "dummy response"
          }
        },
        "_resRetry": [{
            "_body": {
              "any": "body for first try"
            },
            "_headers": [ "header for first try"]
          },
          {
            "_body": {
              "any": "body for second try"
            },
            "_headers": [ "header for second try"]
          }]
      }]
    }
}

Where _retry fields means the number of retries for that specific request and _resRetry will be an array of different responses scenarios.

For the example, the first request will optain a response:

{
  "_body": {
    "any": "dummy response"
  }
}

2 request:

{
  "_body": {
    "any": "body for first try"
  },
  "_headers": [ "header for first try"]
}

3 request:

{
  "_body": {
    "any": "body for second try"
  },
  "_headers": [ "header for second try"]
}

If you make again a request it will start from the beginning as you have achieved the number of retries.

Same request different response

There are scenarios where the user wants to provide different responses for the same request. The library provide the following feature to be able to do it.

It needs to add a custom id in the root of the scenario like the example below:

{
  "_get": {
    "/customers":[
      {
        "_id": "ID_1",
        "_req":{},
        "_res":{
          "_body": {
            "size":100
          }
        }
      },
      {
        "_id": "ID_2",
        "_req":{},
        "_res":{
          "_body": {
            "size":200
          }
        }
      }
    ]
}

Basically, it requires to tell to the library which id to use before making the request.

The library expose three endpoints to deal with the id.

• POST "/__scenario" body: { id: 'CUSTOM_ID' } This request sets the id in the library. For the example above, if we want to response the first scenario, we should make the next request before the mock is executed:

  curl -X POST \
  http://localhost:3005/__scenario \
  -H 'cache-control: no-cache' \
  -H 'content-type: application/json' \
  -d '{
      "id":"ID_1"
  }'

• GET "/__scenario" response: { id: 'CUSTOM_ID' } If we want to know which id is set in the library in that moment, we need to make a a get request. Using the example above:

  curl -X GET \
  http://localhost:3005/__scenario \

• POST "/__scenario/reset Reset the identifier in the library

  curl -X POST \
  http://localhost:3005/__scenario/reset \

Config file

You can add your config file in the root of the mock service or in the root of the project. The name of the file must be .hjs.config.json

At this moment, the developer can use the following options:

Cors Options

You can add corsOptions as the cors library is doing. For example:

{
  "corsOptions":{
    "origin": "http://your-url.com",
    "optionsSuccessStatus": 200
  }
}

Logs

You can include the level of logs fot the mock using morgan options. For example:

{
  "logs": ":method :url :status :res[content-length] - :response-time ms"
}

Port

Expecify the port. It is 3005 by default.

{
  "port": 8081
}

UI

Expecify if you want to enable the ui. By default is disabled.

{
  "ui": {
    "enable": true
  }
}

Compatibility

It requires 1.0.0 or newer versions of @hectorjs/cli.

Respository

https://github.com/hector-js/stub-backend

Please, I am up for feedback and new issues for the respository.

Thank you