Registers after_compiler hooks that write diagnostics to a JSONL file.

Add :diagnostics as the first compiler so the hooks are registered before :elixir runs. This ensures diagnostics are written even when a syntax error aborts the compiler chain.

def project do
  [
    compilers: [:diagnostics] ++ Mix.compilers() ++ [:spex],
    diagnostics: [output: "diagnostics.jsonl"],
    ...
  ]
end

Options

• :output - output file path, defaults to "diagnostics.jsonl". Can also be set via the DIAGNOSTICS_OUTPUT env var.

Project configuration

Options can be set under the :diagnostics key:

def project do
  [
    compilers: [:diagnostics] ++ Mix.compilers() ++ [:spex],
    diagnostics: [output: "build/diagnostics.jsonl"],
    ...
  ]
end