Jest: React Native example

[aaronabramov]

we should probably add RN example to https://github.com/facebook/jest/tree/master/examples
I get asked about it a lot
cc @davidbrear

[DavidBrear]

For the sake of conversation, I've created https://github.com/DavidBrear/jest-react-native-demo which attempts to use jest, react-native-mock, and enzyme but something has been odd because shallow rendering does not create the element with any properties.

[cpojer]

I'll focus on this next week with the release of Jest 14. We are skipping 13 because we are superstitious. cc @zpao.

[calclavia]

Any updates on this issue? I'm having trouble with using Jest and Enzyme as well. Referring to this commit https://github.com/DavidBrear/jest-react-native-demo/commit/5cce66427ead65d168d1b6ed00f4c702b777ef42

Runtime Error
  - Error: Cannot find module './package' from 'index.js'
        at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:197:17)
        at Runtime._resolveModule (node_modules/jest-runtime/build/index.js:304:32)
        at Runtime._getNormalizedModuleID (node_modules/jest-runtime/build/index.js:465:31)
        at Runtime._shouldMock (node_modules/jest-runtime/build/index.js:511:27)
        at Runtime.requireModuleOrMock (node_modules/jest-runtime/build/index.js:263:14)
        at Object.<anonymous> (node_modules/enzyme/node_modules/cheerio/index.js:11:19)
        at Runtime._execModule (node_modules/jest-runtime/build/index.js:352:17)
        at Runtime.requireModule (node_modules/jest-runtime/build/index.js:202:14)
        at Runtime.requireModuleOrMock (node_modules/jest-runtime/build/index.js:266:19)
        at Object.<anonymous> (node_modules/enzyme/build/ReactWrapper.js:17:16)

[astraldragon]

https://github.com/astraldragon/riki

I've got a working project setup (with enzyme), but I had to put an interesting hack in place for anything using the fetch API (https://github.com/astraldragon/riki/blob/31de077b6ecbcbb0c3679d0a14676be08e08b4c0/app/actions/__tests__/library-test.js#L8. I have no clue why. I'm using the fetch-mock library. I'd appreciate any guidance.

Basically if I try to change that test file from saying fetchMock.aMock to fetchMock.mock I get this error from Jest:

Error: /riki/app/actions/__tests__/library-test.js: babel-plugin-jest-hoist: The second argument of `jest.mock` must be a function

EDIT - I found another solution for the fetch-mock library (use their get, post, etc... functions instead of the mock function). @cpojer does jest try to do something with any call to a function that is named mock?

[cpojer]

Thank you for your patience. We launched Jest 14.0 with experimental react-native support:

• Blog Post
• React-Native Tutorial

Please feel free to create new issues after trying out the new integration if any issues remain.