chg: configuarable installation of esbuild

[philippseith]

The config key :installmode controls how the esbuild executable is downloaded and installed.

• :download - downloads esbuild as described in https://esbuild.github.io/getting-started/#download-a-build. :download is default value for this key.
  • :npm - downloads esbuild using an existing npm installation. See https://esbuild.github.io/getting-started/#install-esbuild

By using an existing npm installation, the problems mentioned in https://github.com/phoenixframework/esbuild/issues/26#issuecomment-929834668 are circumvented. Furthermore, the already working npm configuration, including a custom registry and all its security and authentication settings is used.

[josevalim]

Hi @philippseith! Thanks for the PR but I would prefer to not depend on the precise mechanics of npm install. Based on your PR, I pushed a tiny configuration that allows the path to be configured. In your app, you would be to do this:

config :esbuild,
  path: System.get_env("MIX_ESBUILD_PATH")

Now you can do npm install -g esbuild and make it point precisely to the esbuild path. Please give it a try and let me know!

[philippseith]

Cool, that's much simpler. But: It works on linux but on Windows there are some quirks.

• Instead of which esbuildthere iswhere.exe esbuild`
• Instead of export I had to use setx MIX_ESBUILD_PATH C:\\Users\\...\\AppData\\Roaming\\npm\\esbuild
• C:\\Users\\...\\AppData\\Roaming\\npm\\esbuild was the output of where.exe esbuild and causes

  ** (ErlangError) Erlang error: :eacces
  erlang.erl:2217: :erlang.open_port({:spawn_executable, 'C:\\Users\\...\\AppData\\Roaming\\npm\\esbuild'}, [:use_stdio, :exit_status, :binary, :hide, {:args, ["--version"]}])
  (elixir 1.12.3) lib/system.ex:1052: System.do_cmd/3

  There seems to be a problem executing *.cmd files with Erlang. A workaround is to call cmd.exe /c MIX_ESBUILD_PATH instead or setting MIX_ESBUILD_PATH to the location of esbuild.exe. But esbuild.exe is not in path but in ...\npm\node_modules\esbuild

[philippseith]

BTW: The test fails here (both on linux and windows) https://github.com/phoenixframework/esbuild/blob/6c73497492adfa19a513da7145c160bcd59019c6/test/esbuild_test.exs#L21 when the installed version is different to the one required from the test

[josevalim]

@philippseith Yeah, the reason why cmd fails is because where.exe esbuild is not pointing to esbuild, but rather a shim escript that executes esbuild. Pointing to esbuild.exe is the way to go. I have changed the docs in this commit to clarify that: https://github.com/phoenixframework/esbuild/commit/6c73497492adfa19a513da7145c160bcd59019c6