@hectorjs/stub-backend
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. 😄
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
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:
Each scenario contains two sections _req (request) and _res (response) where we place the properties in relation to the request and response.
_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]
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:
- multipart/form-data
The values keyName=ValueName will be matching in the body section like:
{
_body:{
[keyName]:[ValueName]
}
}
- 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
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.jsor with cli
hjs startThe service will be running in the port 3005 waiting for a request.
Make a request:
curl http://localhost:3005/stories/nathan/personThe response will be like this:
{
"name": "Nathan"
}Advance options
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 --bannerhave upper version 0.24.0 hectorjs/stub-cli. For a new mock service: -
hjs new --bannercreate 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