Function check_app 

pub fn check_app(
    dir: &Path,
    parser: &dyn SourceParser,
    plugins: &dyn CompilerPlugins,
    targets: &[CompileDeps],
) -> Result<CheckReport, RunError>

Parse <dir>/src/main.lmn + optional <dir>/src/main.css and validate them without spawning a window. Used by CI / pre-commit hooks.

Parse-time LayoutIR.lint_findings (an unknown attribute, a boolean attribute with an off-list value, bare {name} interpolation) are printed to stderr but never fail the build - check validates AST shape, not style. Run lumenc lint --signals <dir> for the full lint stream.

check is for no one target. targets holds what was resolved for each target the app can be built for: the markup is checked once, accepting the elements of every target’s add-ons, and the scripts are compiled once per target, each against that target’s add-ons, script libraries and @cfg(...) flags, so code written for one target is checked the way that target’s build compiles it.

Requires the source parser (runtime-parse feature).