codelore-lib 0.27.3

//! Shared helper for routing complexity-metric reads through
//! `complexity_metrics_grouped` when `opts.group_file` is set.
//!
//! `apply_grouping` rewrites `changes.path` to group names (hunks are
//! never path-rewritten — hunks of grouped-away paths are dropped,
//! identity-mapped paths keep theirs), but `complexity_metrics` is
//! populated at HEAD-time keyed on raw file paths. Without an analogous
//! rewrite, the `MAX(cognitive) GROUP BY path` reads in `hotspots`,
//! `code_health`, `god_classes`, and `stale_code` silently produced `0`
//! cognitive for grouped entities because `changes.path` (group name)
//! never matched `complexity_metrics.path` (raw path). `apply_grouping`
//! therefore also materialises `complexity_metrics_grouped`: one row per
//! group carrying the per-group `MAX` of every complexity column the
//! `{cm_src}` consumers read (`cognitive`, `cyclomatic`, `loc`, `sloc`,
//! `nargs`, `max_nesting`, `bool_ops`) plus `MAX` `kind='unit'` MI —
//! analyses opt in
//! by reading from the table named here.
//!
//! Centralised so the four affected analyses share one dispatch. This
//! solves the same class of problem as `analyses::lineage` (swap an
//! analysis's source table based on an `Options` flag) but with a
//! deliberately different mechanism: `lineage` regex-rewrites `FROM
//! changes` in place, whereas this exposes a table name that callers
//! substitute into an explicit `{cm_src}` placeholder. A placeholder is
//! simpler and safer than a general SQL rewrite for the small, fixed set
//! of complexity-reading analyses — they are NOT mirror images.

use crate::Options;

/// Returns the complexity-metric source table for `opts`.
///
/// When grouping is active, this names the pre-aggregated
/// `complexity_metrics_grouped` materialised by `apply_grouping`; the
/// table has one row per group with cognitive + MI already collapsed
/// via `MAX`. Wrapping the read in `MAX(cognitive) GROUP BY path` is a
/// no-op on this source, so analyses can use the SAME CTE shape under
/// either source — only the `FROM` table swaps.
#[must_use]
pub fn source_table(opts: &Options) -> &'static str {
    if opts.group_file.is_some() {
        "complexity_metrics_grouped"
    } else {
        "complexity_metrics"
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::path::PathBuf;

    #[test]
    fn returns_raw_table_without_grouping() {
        let opts = Options::default();
        assert_eq!(source_table(&opts), "complexity_metrics");
    }

    #[test]
    fn returns_grouped_table_when_group_file_set() {
        let opts = Options {
            group_file: Some(PathBuf::from("groups.txt")),
            ..Options::default()
        };
        assert_eq!(source_table(&opts), "complexity_metrics_grouped");
    }
}