Support separate wasm file as well as inlined wasm file

[isaac-mason]

The main advantages of a separate wasm file are reduced bundle size and faster initialisation.

The downside is there are extra considerations required for supporting bundler configuration or serving the wasm from somewhere.

Continuing to support the existing inlined wasm flavour is important for ease of use.

There are several potential approaches. To name some:

• Have two versions of the recast-navigation npm package, one with an inlined wasm, one with a separate wasm file
  • rapier.js takes this approach
• Have one recast-navigation npm package, support passing an instance of @recast-navigation/wasm (separate file, inlined wasm, asm.js, other) to init
  • if there was a default, would need to make sure it could be tree-shaken

[isaac-mason]

wip branch trying the second approach here: https://github.com/isaac-mason/recast-navigation-js/tree/feat/specify-recast-impl

Right now the the wasm flavor (separate wasm file, not inlined like wasm-compat) doesn't work on node.

The emscripten build parameter ENVIRONMENT needs to be updated to include 'node' so there is node friendly logic for reading the wasm. However, these node code paths cause issues with some bundlers (at least webpack 5) due to the unrecognised node builtins. These warnings/errors can be surpressed and the build output will still work, but this is likely to cause confusion. Some bundlers such as vite don't have the issue.

Some options:

• (short term) Accept and document that the wasm flavor doesn't work on node, and that wasm-compat should be used
• Have a web + node wasm flavor, document the webpack 5 issue as a known issue
• Have separate web and node wasm builds.
  • This isn't ideal, we'd need to have 4 builds (wasm-node, wasm-web, wasm-compat-node, wasm-compat-web) , and it may not be straightforward/possible to configure a package.json so the correct one is used automatically

[isaac-mason]

78cf5df

[isaac-mason]

Starting with the short term option mentioned above

(short term) Accept and document that the wasm flavor doesn't work on node, and that wasm-compat should be used