reason-detox

what

Reasonml/Rescript bindings for the Detox end-to-end testing framework. See here for a complete example project using this library.

why

• you are using reason-react-native and want to write end-to-end test's without introducing js
• you are using plain old React Native and want to try introducing Reasonml in a lightweight way

status

• experimental but definitely usable, building blocks are there just needs a few more primitives adding

how

pre-installation

• install detox for jest as per the standard instructions
• ensure you can successfully run a standard detox test before continuing

installation

1. install reason-detox

   yarn add --dev jest @glennsl/bs-jest bs-let https://github.com/alltonp/reason-detox

2. in bsconfig.json
   1. add "@glennsl/bs-jest", "reason-detox" to "bs-dependencies"
   2. add "ppx-flags": ["bs-let/ppx"]
   3. add to "sources":

   {
     "dir": "e2e",
     "type": "dev"
   }

3. update e2e/config.json with:

     "testRegex": "\\Test\\.bs.js$",
     "transformIgnorePatterns": [
       "node_modules/(?!(jest-)?react-native|react-(native|universal|navigation)-(.*)|@react-native-community/(.*)|@react-navigation/(.*)|bs-platform|(@[a-zA-Z]+/)?(bs|reason|rescript)-(.*)+)"
     ]

4. that's it!

creating a test

• save the following in e2e/firstTest.re

open Jest;
open ReasonDetox;

describe("The Test", () => {
  testPromise("example", _ => {
  
    //TIP: everything that returns a Promise must use let%Await 
    let%Await _ = expect(Id("count")) |> toHaveText("0");
    let%Await _ = tap(Text("+"));
    let%Await _ = expect(Id("count")) |> toHaveText("1");
    let%Await _ = tap(Text("-"));
    let%Await _ = expect(Id("count")) |> toHaveText("0");

    //TIP: must call this at the end to tell jest we are done, otherwise the test will run until timeout and then fail 
    Js.Promise.resolve(pass);
  })
});

run the test

• detox test -f e2e/firstTest.bs.js

running all tests

• detox test