esbuild 0.15.9

v0.15.9

on Node.js NPM

Fix an obscure npm package installation issue with --omit=optional (#2558)

The previous release introduced a regression with npm install esbuild --omit=optional where the file node_modules/.bin/esbuild would no longer be present after installation. That could cause any package scripts which used the esbuild command to no longer work. This release fixes the regression so node_modules/.bin/esbuild should now be present again after installation. This regression only affected people installing esbuild using npm with either the --omit=optional or --no-optional flag, which is a somewhat unusual situation.

More details:

The reason for this regression is due to some obscure npm implementation details. Since the Go compiler doesn't support trivial cross-compiling on certain Android platforms, esbuild's installer installs a WebAssembly shim on those platforms instead. In the previous release I attempted to simplify esbuild's WebAssembly shims to depend on the esbuild-wasm package instead of including another whole copy of the WebAssembly binary (to make publishing faster and to save on file system space after installation). However, both the esbuild package and the esbuild-wasm package provide a binary called esbuild and it turns out that adding esbuild-wasm as a nested dependency of the esbuild package (specifically esbuild optionally depends on @esbuild/android-arm which depends on esbuild-wasm) caused npm to be confused about what node_modules/.bin/esbuild is supposed to be.

It's pretty strange and unexpected that disabling the installation of optional dependencies altogether would suddenly cause an optional dependency's dependency to conflict with the top-level package. What happens under the hood is that if --omit=optional is present, npm attempts to uninstall the esbuild-wasm nested dependency at the end of npm install (even though the esbuild-wasm package was never installed due to --omit=optional). This uninstallation causes node_modules/.bin/esbuild to be deleted.

After doing a full investigation, I discovered that npm's handling of the .bin directory is deliberately very brittle. When multiple packages in the dependency tree put something in .bin with the same name, the end result is non-deterministic/random. What you get in .bin might be from one package, from the other package, or might be missing entirely. The workaround suggested by npm is to just avoid having two packages that put something in .bin with the same name. So this was fixed by making the @esbuild/android-arm and esbuild-android-64 packages each include another whole copy of the WebAssembly binary, which works because these packages don't put anything in .bin.