Jest not picking latest plugin from babel.config.js

Question

I have my own babel plugin mentioned in babel.config.js and when I change the plugin, jest doesn't pick the updated plugin code and breaks tests. When I run npx jest --no-cache, updated changes are picked up.

I do not want to run with --no-cache everytime I update the plugin.

I am curious to know how jest picks the latest babel plugins, when they are updated in npm artifactory?

I have mentioned my plugin in babel.config.js as:

module.exports = function (api) {
  api.cache(true);

  const presets = ["@babel/preset-env", "@babel/preset-react"];
  const plugins = [
    "@babel/plugin-syntax-dynamic-import",
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-transform-runtime",
    ["module:@babel-plugin-dynamic-import-override", {
      options: someOptions
    }]
  ];

  return {
    presets,
    plugins
  };
}

Also, what changes do I make to my jest.config.js to make it pick the latest plugins?

Answer 1

Jest caches the babel config for performance boost. This is same as providing cacheDirectory: true with babel-loader in webpack. babel-loader also has option to burst cache using cacheIdentifier, which jest doesn't has as of now and doesn't plan to add it in future too.

However, there is workaround by extending babel-jest. Detailed discussion can be read here: https://github.com/facebook/jest/issues/8932