CODEWITHSUNDEEP
javascriptreact-nativeecmascript-6metro-bundler
MatthewP
MatthewP

Reputation: 187

How to require module only if exist. React native

Example:

let tmp;

try {
  tmp = require('module-name');
} catch(e) {
  return;
}

I get error (react native Metro Bundler):

error: bundling failed: Error: Unable to resolve module `module-name` from ...

How to require "module-name" only if exist?

Upvotes: 3

Views: 1820

Answers (3)

Petr Bela
Petr Bela

Reputation: 8741

Loading optional dependencies via try-catch has been added in Metro 0.59, which in turn means that you should be able to use your original code in React Native 0.63 if you turn it on in metro.config.js:

module.exports = {
  transformer: {
    allowOptionalDependencies: true,
  },
}

Upvotes: 0

gran33
gran33

Reputation: 12981

That's what works for me:

let myPackage;
const myPackageToRequire = 'my-package-to-require';
try {
  myPackage = require.call(null, myPackageToRequire);
} catch (e) {}

The variable definition const myPackageToRequire = 'my-package-to-require'; is necessary here.

Hope I helped.

Upvotes: 3

Pritish Vaidya
Pritish Vaidya

Reputation: 22209

Use require.resolve which will return resolved file name.

function checkModuleAvailability (module) {
  try {
    require.resolve(module);
    return true
  } catch(e) {
    console.log(`${module} not found`);
  }
  return false
}

const moduleAvailable = checkModuleAvailability(MODULE_NAME) // true or false

Upvotes: -1

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