[Documentation] Document the failure mode for unsupported node-specific features in dependencies about esbuild HOT 1 OPEN

Will it be a compile-time or run-time failure?

Mostly runtime error.

• __dirname is considered a global variable, like window, which throws a runtime error when it cannot find such reference.
• import.meta.url is an ESM-only global variable, esbuild will show warnings when bundling to non-ESM formats like CJS or IIFE.
• fs.readFileSync() means that the dependencies' source may rely on its location in the file system. esbuild can only bundle sources that are referenced by import/requires. So this one will cause related files not being bundled and throws runtime error when there's no such file.
• .node files are not in esbuild's default loaders list, so esbuild will throw an error of not found loader for such file extension. People may use --loader:.node=file to successfully bundle it.

There're more cases, but one significant knowledge is that esbuild runs static analyzing on the source code. Without actually running the code, esbuild can only bundle "obvious" files that are referenced with each other via import/requires. The "bundle" also does not mean it simulates the whole file system, so any code that depends on a real file system to work will likely to break after bundling.

from esbuild.