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It is a common pattern in Node to support optional dependencies via requires in try..catch blocks. Browserify doesn't support this by default and throws a compile time error when it cannot find a module. You can solve the problem by using browserify's exclude option, but this works globally instead of at a per-module level. This transform fixes the problem by moving the compile time error to a runtime error for requires of missing modules inside try..catch blocks.


The transform would transform the following code such that requiring missing-module would throw a runtime error instead of a compile time error, making the code work as expected.

try {
  var x = require('missing-module');
} catch (e) {
  var x = require('replacement-module');

To set it up in browserify, add this to your package.json:

  "transform": ["browserify-optional"]