Profiled Mock API

This is a server built on top of express which serves JSON and XML files based on file/folder configuration. The root directory of the response files can be separated by "profiles."

Getting Started

Step 1: Create mock server

Create a new index.ts file:

import { MockApiServer, GlobalLogger, LogLevel } from 'profiled-mock-api'

GlobalLogger.getInstance().logLevel = LogLevel.ALL

const mockServer: MockApiServer = new MockApiServer({
    initialActiveProfile: "default", // default: 'default'
    port: 3000, // default 3000
    profileDirectory: "responses"
})


mockServer.start()

Step 2: Create response files

With file structure:

node_modules
responses
    default
        ping.json
index.ts
package.json

we can create ping.json:

{
    "message": "pong"
}

The directory responses is where the profile directories will be stored. responses/default is the root directory where responses of the "default" profile will be served from.

Step 3: Run the server:

ts-node index.ts

Step 4: Call the endpoint:

GET http://localhost:3000/ping

Specify method and response

Option 1: Simple files:

Directory Structure:

resources
    default
        ping.json
        some
            deep
                path
                    status.json

Calls:

• GET http://localhost:3000/ping
• POST http://localhost:3000/ping
• any http method http://localhost:3000/ping
• GET http://localhost:3000/some/deep/path/status
• POST http://localhost:3000/some/deep/path/status
• any http method http://localhost:3000/some/deep/path/status

Option 2: Complex Files with HTTP Method:

Directory Structure:

resources
    default
        ping.GET.json
        ping.POST.json
        some
            deep
                path
                    status.GET.json
                    status.PUT.json

Calls:

• GET http://localhost:3000/ping
• POST http://localhost:3000/ping
• GET http://localhost:3000/some/deep/path/status
• PUT http://localhost:3000/some/deep/path/status

Option 3: Complex Files with HTTP Method and response status:

Directory Structure:

resources
    default
        ping.GET.200.json
        ping.POST.500.json
        some
            deep
                path
                    status.GET.200.json
                    status.PUT.201.json
        health
            check.500.json

Calls:

• GET http://localhost:3000/ping
• POST http://localhost:3000/ping
• GET http://localhost:3000/some/deep/path/status
• PUT http://localhost:3000/some/deep/path/status

Option 4: Directories:

Directory Structure:

resources
    default
        ping
            GET.json
            POST.json
        health
            check
                GET.json
                POST.201.json
                PUT.500.json

Calls:

• GET http://localhost:3000/ping
• POST http://localhost:3000/ping
• GET http://localhost:3000/health/check
• POST http://localhost:3000/health/check
• PUT http://localhost:3000/health/check

Profiles

Suppose we have a directory structure as follows:

resources
    test_case_happy_path
        ping
            GET.200.json
        health
            check
                GET.200.json
    test_case_evtang_broken
        ping
            GET.500.json
        health
            check
                GET.500.json

All Profiles:

Profiles can be seen at GET http://localhost:3000/profiles:

{
    "test_case_happy_path": {
        "responseFileBasePath": "responses\\test_case_happy_path"
    },
    "test_case_evtang_broken": {
        "responseFileBasePath": "responses\\test_case_evtang_broken"
    }
}

Active Profiles:

The active profile can be seen at GET http://localhost:3000/activeProfile:

{
    "activeProfile": "test_case_happy_path"
}

Changing Active Profile:

Option 1: with GET

GET http://localhost:3000/setActiveProfile?newlyActiveProfile=test_case_happy_path:

Response 200:

{
    "activeProfile":"test_case_happy_path"
}

Option 2: with POST

The active profile can be seen at POST http://localhost:3000/activeProfile: with body

{
    "newlyActiveProfile": "test_case_happy_path"
}

Response 200:

{
    "activeProfile":"test_case_happy_path"
}

Custom Middleware

Response bodies and status codes cover most mocking needs, but some real APIs require things this project has no other file-based way to express -- most commonly, custom response headers. For example, an API where GET /employee/:id returns an ETag header that must then be echoed back on PUT /employee/:id.

For cases like this, configureApp lets you add your own express middleware. It's called with the underlying express app right after it's created, before MockApiServer registers its own body-parsing/routing -- so anything it sets still applies to every response, including responses served from your response files:

import { MockApiServer } from 'profiled-mock-api'

const mockServer: MockApiServer = new MockApiServer({
    initialActiveProfile: "default",
    port: 3000,
    profileDirectory: "responses",
    configureApp: (app) => {
        app.use((req, res, next) => {
            res.setHeader('ETag', '"some-fixed-etag"')
            next()
        })
    }
})

mockServer.start()