CI should test whether generated files match latest sources

[osteele]

The CI should test whether the generated files (expressions.go and y.go) match the sources.

The following GitHub Action will do this:

  - name: Test generated code
  - run: |
      make generate
      git diff --exit-code

The missing pieces are:

1. Installing Ragel

This works:

  - name: Install Ragel
    run: |
      sudo apt-get update
      sudo apt-get install 

However, this requires apt-get update and apt-get install on each run.

Is there a way to cache this? Alternatively, should this action use a Docker image that includes Ragel?

2. Installing goyacc

I tried this:

Add a step:

  - name: Install generators
    run: make setup
  - name: Run generators
    run: make generate

(make setup includes go install golang.org/x/tools/cmd/goyacc. make generate runs go generate ./....)

This produces an error:

expressions/parser.go:3: running "goyacc": exec: "goyacc": executable file not found in $PATH
make: *** [Makefile:24: generate] Error 1
Error: Process completed with exit code 2.