Jest: Failed prop type: Invalid prop `source` supplied to `Image`, expected one of type [number]

Question

I am using jest with react-native to run unit test cases. And whenever it encounters Image it throws the following warning

 Warning: Failed prop type: Invalid prop `source` supplied to `Image`, expected one of type [number].
          at Component (~/.../node_modules/react-native/jest/mockComponent.js:28:18)
          at SummaryTile (~/.../src/components/home/SomeComponent.tsx:18:3)

      23 |   >
      24 |     {backgroundImg || (
    > 25 |       <Image
         |       ^
      26 |         source={require('images/cloud.png')}
      27 |       />

I tried to replace the code to

<Image src={{uri: require('images/cloud.png')}} />

as suggested in https://stackoverflow.com/a/36460928/3855179 but it started throwing the following warning and the application breaks

Warning: Failed prop type: Invalid prop `source` supplied to `Image`, expected one of type [string, number].
    at Image (http://expo_url:19000/node_modules/expo/AppEntry.bundle?platform=android&dev=true&hot=false&strict=false&minify=false:76209:43)

Jest Version: 26.6.3
React Native version: 0.64.3
Node Version: 16.14.2

Any idea how this can be handled?

Answer 1

It would be helpful to see your file structure along with the jest configuration file.

But my best guess is - jest isn't able to find the file in the designated location.

Few things that can be tried:

(1) try changing file location to be a bit more explicit like so:

eg - if image in same directory -- source={require('./images/cloud.png')}

eg - if one directory up -- source={require('../images/cloud.png')}

---

(2) try mocking out the image in test file like so:

jest.mock("images/cloud.png")

---

(3) Specify a location in jest configuration file (or in package.json file if you have a jest key there) for all image types, this way jest will use that as the image source whenever it encounters an image:

eg -

 moduleNameMapper: {
      "\\.(jpg|jpeg|png|svg)$": "<rootDir>/images/dummy-image.js",
    }

More doco on moduleNameWrapper here - https://jestjs.io/docs/configuration#modulenamemapper-objectstring-string--arraystring

Answer 2

In my case, I was trying to use an image, that has an space in its name, like <rootDir>/stupidly_named images.png. It's seems, React Native is happy with these naming, but not Jest. Filling in the space (<rootDir>/stupidly_named_images.png) fixed the error. And I am not using any moduleNameWrapper:

"react-native": "0.68.2"
"jest": "^28.1.0"
"@testing-library/react-native": "^9.1.0"