[Feature Request] Permit imports of Node buffer module in workflows

[silasdavis]

Is your feature request related to a problem? Please describe.

It would be useful to permit uses of the builtin buffer on the import tree for workflows.

In my particular case I have parsing logic to convert workflow input types into richer domain types that relies on buffer.

Describe the solution you'd like

I note that all builtinModules are included in disallowedModules, I'm not sure if this is because you would need to shim them in the v8 isolate explicitly or if it is down to non-determinism issues with Buffer. unsafeAlloc and friends perhaps?

I would assume otherwise that buffer would be safe to us (I have BigNumber implementations depending on it).

The solution I would like is for an exemption to be made similar to that which exists for assert.

Additional context

Incidentally it would be really handy to emit some additional context when reporting problematic modules. The error message lists the modules but not their source, however data.context in the callback here:

sdk-typescript/packages/worker/src/workflow/bundler.ts

Line 193 in 2073c53

this.foundProblematicModules.add(module);

Does have access to the module which actually made the call which helps a lot in narrowing down the source of the bad module import.

[mjameswh]

After discussion, our team has determined that it's preferable not to provide out-of-the-box support for Node's Buffer API, since that goes against some of our mid-term and long-term objectives, notably regarding the possibly of supporting other JavaScript runtimes (eg. Deno, browser, etc).

Instead, we encourage users to load appropriate polyfills from their Webpack bundler. A sample will soon be added demonstrating how to do so.