praxis-cli 0.2.0

//! The `praxis check` command: load a `.px` file, run the front end, render any
//! diagnostics, and return the exit code.
//!
//! Exit codes are [`crate::exit_code`]'s closed set: `OK` when there are no
//! errors, `FAILED` when any language error is reported, `USAGE` when the file
//! cannot be read. `check::run` prints its own diagnostics and never returns
//! `Err` for a user-facing problem, so the code it returns is the final one.
//!
//! # The front end is not here (ADR-097)
//!
//! §14.2 requires the CLI and the LSP to share one front-end query API:
//! `praxis_lsp::query::Snapshot`. The parse → analyze → concatenate →
//! sort-by-span sequence lives there, stated once, so a divergence between what
//! `praxis check` prints and what the editor underlines is unrepresentable
//! rather than merely unlikely.

use praxis_lsp::Revision;
use praxis_lsp::query::Snapshot;

use crate::color_mode::ColorMode;
use crate::{diagnostic_render, exit_code, source_file};

/// Run the `check` command against `file`. Returns the process exit code.
pub fn run(file: &str, color: ColorMode) -> anyhow::Result<i32> {
    let text = match source_file::read(file) {
        Ok(t) => t,
        Err(code) => return Ok(code),
    };

    // One snapshot, one revision: a process that exits has no revisions to
    // invalidate. The queries it answers are the ones the language server asks.
    let snapshot = Snapshot::new(file, text, Revision(0));
    let diagnostics = snapshot.diagnostics();

    let rendered =
        diagnostic_render::render_all(snapshot.source_map(), &diagnostics, color.palette());
    diagnostic_render::write_to(&mut std::io::stderr(), &rendered)?;

    Ok(if rendered.has_errors() {
        exit_code::FAILED
    } else {
        exit_code::OK
    })
}