webpack

Full webpack documentation: https://webpack.js.org/configuration/.

Using webpack helps reduce the install- and startup-time of large extensions because instead of hundreds of files, a small set of files is produced.

How to fix "dynamic require", "Module not found", "the request of a dependency is an expression" etc. webpack errors:

Webpack works by parsing all .ts/.js code, finding 'require' and 'import', and sucking in the target files directly into the bundle. At runtime, the modified require/import looks into webpack's list of bundled modules. Since this happens at compile time, if the module can't be found or the argument to require is an expression, this causes problems (an error when webpacking and an exception at runtime).

These are common ways of fixing the problem:

1. Ask the source author to make the code webpack-friendly.

   E.g. by removing the use of require for loading JSON files (see https://github.com/Microsoft/vscode-nls/commit/3ec7623fd86fc5e38895fe1ac594d2564bb2b755#diff-8cfead41d88ad47d44509a8ab0a109ad). This is not always possible or feasible.

2. ContextReplacementPlugin - the most confusing (https://iamakulov.com/notes/webpack-contextreplacementplugin/)

   This is used when the target module does exist but webpack can't determine a static path at compile time because it contains an expression (e.g. require('./languages/' + lang)).

3. StringReplacePlugin (https://github.com/jamesandersen/string-replace-webpack-plugin)

   Allows you to do regex replacement of the source code make it webpack-friendly before webpack processes the file

4. ExternalNodeModules

   Add a Node.js module name to the externalModules variable in order to have the entire module excluded from being bundled. It will instead be copied to ./dist/node_modules and picked up there through normal Node.js import/require mechanisms. Since it will not be processed by webpack and has no access to webpack's set of bundled modules, all dependencies of this module also have to be (automatically) excluded, so use sparingly.