Make the react-native entry point Jest compatible #6012
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* Remove the need to create a custom resolver in jest code testing realm * This ensures there are no breaking changes in current users tests
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| entryPoint = require("./dist/bundle.react-native"); | ||
| } | ||
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| module.exports = entryPoint.Realm; |
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I'd suggest simply inlining this assignment. No need to store it in entryPoint.
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Good idea. I was doing a lot of dancing around how metro bundled this, to ensure it didn't pre-load the node entry point. Setting require to a variable was the solution.
| @@ -19,4 +19,19 @@ | |||
| /* eslint-disable @typescript-eslint/no-var-requires -- We're exporting using CJS assignment */ | |||
| /* eslint-env commonjs */ | |||
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| module.exports = require("./dist/bundle.react-native").Realm; | |||
| // eslint-disable-next-line no-undef -- In React Native, process is not defined, but in Jest it is | |||
| const isJest = process?.env?.JEST_WORKER_ID !== undefined; | |||
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I'm a bit sad that we need to do this 😞 It would be better if we could find a way to keep this pure from runtime checks of the environment ... historically we've been bitten by the brittleness of these many times before.
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Also - I'm surprised you're not getting an Uncaught ReferenceError: process is not defined when running on React Native 🤔
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We can't get around the react-native preset for jest, which is basically ensuring the react-native entry point is being loaded. I did a lot of digging around this and this was the best solution I could find. At least it's very dependent on Jest and has very little impact on the experience.
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'm surprised you're not getting an Uncaught ReferenceError: process is not defined when running on React Native 🤔
I need to refine the comment. process is actually defined in react-native, but for some reason it is not typed.
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which is basically ensuring the react-native entry point is being loaded
As per that link, it looks to me that we could probably export the Node.js bundle via the require condition (since it's giving priority to require over react-native and the opposite is true for the defaults of the metro bundler) and avoid the runtime check?
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How do we set the require condition for our users?
The linked code is ran by adding preset: "react-native" to the jest config, which is automatically done when initializing a React Native project. Jest isn't looking for this automatically in imported packages, as far as I can tell.
Jest also doesn't allow for multiple presets
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Add this line
"require": "./index.node.js",
after
realm-js/packages/realm/package.json
Line 31 in 0b9dd8b
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Oh boy...that works!
What, How & Why?
This closes #6003
☑️ ToDos
Compatibilitylabel is updated or copied from previous entryCOMPATIBILITY.mdpackage.jsons (if updating internal packages)Breakinglabel has been applied or is not necessaryIf this PR adds or changes public API's: