Testing

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• About

About [↑]

The two decorators @Describe() and @It() are useful tools to save metadata into Controllers. This can be used in contextes, like unit testing.

While @Describe() can be used to group tests, does @It() setup one or more test scenarios for specific request methods:

import {
  Controller,
  ControllerBase,
  Describe,
  GET,
  IHttpRequest,
  IHttpResponse,
  It,
} from "@egomobile/http-server";

@Controller()
@Describe("My controller")
export default class MyController extends ControllerBase {
  @GET("/foo/:bar")
  @It("should return BUZZ in code with status 202", {
    expectations: {
      body: "BUZZ",
      status: 202,
    },
    parameters: {
      bar: "buzz",
    },
  })
  async index(request: IHttpRequest, response: IHttpResponse) {
    response.writeHead(202);
    response.write(request.params!.bar.toUpperCase());
  }
}

Both decorators only collect the data. This library does not implement a working testing framework by itself!

What it does, is to provide an event pattern. An application can listen to an event, called test:

import { createServer } from "@egomobile/http-server";

const app = createServer();

// event, that is executed, if a test,
// setupped by `@It()`, is requested
app.once("test", async (context) => {
    // context => https://egomobile.github.io/node-http-server/interfaces/ITestEventHandlerContext.html
});

await app.test();

// alternative:
//
// if you set `EGO_RUN_SETUP` to a truthy value like `1`
// the server does not start listening, instead it simply
// runs `app.test()`
//
// await app.listen();

In many HTTP server application, the SuperTest library is used to realize endpoint testing.

It is quite simple to integrate its features into the test framework:

import assert from "assert";
import supertest from "supertest";
import { createServer } from "@egomobile/http-server";

/// ...

// event, that is executed, if a test is requested
app.once("test", async (context) => {
  const {
    body,
    description,
    escapedRoute,
    expectations,
    group,
    headers,
    httpMethod,
    server,
  } = context;

  try {
    process.stdout.write(`Running test [${group}] '${description}' ... `);

    // prepare request ...
    // HTTP method ...
    let request = supertest(server)[httpMethod](escapedRoute);
    // request headers ...
    for (const [headerName, headerValue] of Object.entries(headers)) {
      request = request.set(headerName, headerValue);
    }

    // send it
    const response = await request.send(body);

    assert.strictEqual(response.statusCode, expectations.status);

    // maybe some more code checking headers and
    // body data from `expectations` ...

    process.stdout.write(`✅\n`);
  } catch (error) {
    process.stdout.write(`❌: ${error}\n`);
  }
});

/// ...