codelore-lib 0.29.1

//! Combined exclusion filter for HEAD-time path walks.
//!
//! Sources, applied in order of precedence (later wins):
//! 1. Hardcoded essentials: just `.git/` (codelore can't analyze its
//!    own metadata).
//! 2. `.gitignore`, `.git/info/exclude`, parent-directory `.gitignore`s
//!    via the `ignore` crate's `gitignore::GitignoreBuilder`. Respects
//!    standard gitignore syntax including negation (`!keep.txt`),
//!    directory-only patterns (`build/`), and per-directory inheritance.
//! 3. `.codeloreignore` at the repo root — `CodeLore`-specific additions
//!    that the user wouldn't put in `.gitignore` (e.g. translation
//!    files that ARE checked in but you don't want `CodeLore` to analyze).
//! 4. User `--exclude '<glob>'` CLI flags. Treated as plain globset
//!    patterns (no gitignore semantics) since they're typed at the
//!    shell.
//!
//! Why .gitignore by default: it's the user's project-local "what's
//! not my code" manifest — exactly the answer to "should `CodeLore`
//! analyze this?" The result is that out of the box, `CodeLore` skips
//! `node_modules`, `target`, `dist`, lockfiles, etc. for any
//! conventionally-set-up project, without `CodeLore` reinventing the
//! list. Users with unconventional layouts can override via
//! `.codeloreignore` or `--include-ignored` (opt-out).

use std::path::Path;

use crate::{CodeLoreError, Options, Result};

/// Combined matcher. `is_excluded(rel_path)` returns true when the
/// path should be skipped by any HEAD-time scan (complexity, clones,
/// etc.).
pub struct PathsFilter {
    /// User `--exclude '<glob>'` patterns. Matched as plain globset.
    globset: globset::GlobSet,
    /// .gitignore + .codeloreignore + .git/info/exclude rules.
    gitignore: ignore::gitignore::Gitignore,
}

impl PathsFilter {
    /// Build the combined filter for `opts.repo_path`. Honours
    /// `opts.exclude_patterns` (user `--exclude`) and the auto-detected
    /// gitignore set unless `opts.include_ignored` is true.
    pub fn from_opts(opts: &Options) -> Result<Self> {
        let mut gb = ignore::gitignore::GitignoreBuilder::new(&opts.repo_path);
        if !opts.include_ignored {
            // .gitignore at the repo root + auto-discovery of parent
            // .gitignores + .git/info/exclude. add() returns None on
            // success or Some(err) on parse error; we surface parse
            // errors but tolerate missing files.
            let gitignore_path = opts.repo_path.join(".gitignore");
            if gitignore_path.is_file()
                && let Some(err) = gb.add(&gitignore_path)
            {
                return Err(CodeLoreError::Analysis(format!(
                    ".gitignore at {}: {err}",
                    gitignore_path.display()
                )));
            }
            // .git/info/exclude is the user's local-only ignore list
            // (not checked in). Honour it too — same precedence as
            // .gitignore per the spec.
            let info_exclude = opts.repo_path.join(".git/info/exclude");
            if info_exclude.is_file()
                && let Some(err) = gb.add(&info_exclude)
            {
                return Err(CodeLoreError::Analysis(format!(
                    ".git/info/exclude at {}: {err}",
                    info_exclude.display()
                )));
            }
            // .codeloreignore — `CodeLore`-specific additions. Lives
            // alongside .gitignore in the user's repo.
            let codelore_ignore = opts.repo_path.join(".codeloreignore");
            if codelore_ignore.is_file()
                && let Some(err) = gb.add(&codelore_ignore)
            {
                return Err(CodeLoreError::Analysis(format!(".codeloreignore: {err}")));
            }
        }
        let gitignore = gb
            .build()
            .map_err(|e| CodeLoreError::Analysis(format!("build gitignore matcher: {e}")))?;

        let mut gsb = globset::GlobSetBuilder::new();
        for pat in &opts.exclude_patterns {
            let g = globset::Glob::new(pat)
                .map_err(|e| CodeLoreError::Analysis(format!("--exclude {pat:?}: {e}")))?;
            gsb.add(g);
        }
        let globset = gsb
            .build()
            .map_err(|e| CodeLoreError::Analysis(format!("build --exclude globset: {e}")))?;

        Ok(Self { globset, gitignore })
    }

    /// True if `rel_path` (relative to the repo root) should be skipped.
    /// Pass `is_dir` so directory-only `.gitignore` rules (`build/`)
    /// match correctly when called per-file.
    #[must_use]
    pub fn is_excluded(&self, rel_path: &Path, is_dir: bool) -> bool {
        if self.globset.is_match(rel_path) {
            return true;
        }
        // matched_path_or_any_parents() also checks ancestor dirs so a
        // file under `dist/foo/bar.js` is excluded when only `dist/` is
        // listed. ignore_case=false since gitignore is case-sensitive
        // on Linux (the platform git was designed for).
        match self.gitignore.matched_path_or_any_parents(rel_path, is_dir) {
            ignore::Match::Ignore(_) => true,
            ignore::Match::Whitelist(_) | ignore::Match::None => false,
        }
    }
}

/// Always-on hardcoded skip — `.git/` directory contents. We can never
/// analyze our own metadata source.
#[must_use]
pub fn is_git_metadata(rel_path: &Path) -> bool {
    rel_path
        .components()
        .next()
        .and_then(|c| c.as_os_str().to_str())
        == Some(".git")
}

// `tempfile`-backed like every fixture-writing unit module in this crate,
// hence the `test-support` gate.
#[cfg(all(test, feature = "test-support"))]
mod tests {
    use std::path::Path;

    use super::{PathsFilter, is_git_metadata};
    use crate::Options;

    /// Build a filter over a tempdir seeded with the given ignore-family
    /// files (`(rel_path, contents)`), plus `--exclude` patterns.
    fn filter_with(
        files: &[(&str, &str)],
        exclude: &[&str],
        include_ignored: bool,
    ) -> (tempfile::TempDir, PathsFilter) {
        let dir = tempfile::tempdir().expect("tempdir");
        for (rel, contents) in files {
            let path = dir.path().join(rel);
            if let Some(parent) = path.parent() {
                std::fs::create_dir_all(parent).expect("mkdir");
            }
            std::fs::write(&path, contents).expect("write ignore file");
        }
        let opts = Options {
            repo_path: dir.path().to_path_buf(),
            exclude_patterns: exclude.iter().map(ToString::to_string).collect(),
            include_ignored,
            ..Options::default()
        };
        let filter = PathsFilter::from_opts(&opts).expect("build filter");
        (dir, filter)
    }

    #[test]
    fn gitignore_rules_apply_including_negation_and_ancestors() {
        let (_dir, f) = filter_with(&[(".gitignore", "dist/\n*.log\n!keep.log\n")], &[], false);
        // Directory-only rule excludes descendants via ancestor matching.
        assert!(f.is_excluded(Path::new("dist/bundle.js"), false));
        assert!(f.is_excluded(Path::new("debug.log"), false));
        // Negation wins over the earlier wildcard, per gitignore semantics.
        assert!(!f.is_excluded(Path::new("keep.log"), false));
        assert!(!f.is_excluded(Path::new("src/main.rs"), false));
    }

    #[test]
    fn git_info_exclude_applies_like_gitignore() {
        // Untracked local-only ignore list — the load-bearing cache-key
        // source (see `Options::canonical_json`): nothing else about a run
        // moves when it is edited.
        let (_dir, f) = filter_with(&[(".git/info/exclude", "scratch.txt\n")], &[], false);
        assert!(f.is_excluded(Path::new("scratch.txt"), false));
        assert!(!f.is_excluded(Path::new("src/lib.rs"), false));
    }

    #[test]
    fn codeloreignore_extends_the_gitignore_set() {
        let (_dir, f) = filter_with(
            &[(".gitignore", "dist/\n"), (".codeloreignore", "locales/\n")],
            &[],
            false,
        );
        assert!(f.is_excluded(Path::new("dist/x.js"), false));
        assert!(f.is_excluded(Path::new("locales/de.json"), false));
        assert!(!f.is_excluded(Path::new("src/lib.rs"), false));
    }

    #[test]
    fn include_ignored_disables_the_ignore_family_but_not_exclude_globs() {
        let (_dir, f) = filter_with(
            &[(".gitignore", "dist/\n"), (".codeloreignore", "locales/\n")],
            &["**/*.gen.rs"],
            true,
        );
        assert!(!f.is_excluded(Path::new("dist/x.js"), false));
        assert!(!f.is_excluded(Path::new("locales/de.json"), false));
        // `--exclude` is an explicit user instruction, not gitignore-derived
        // — `--include-ignored` must not neuter it.
        assert!(f.is_excluded(Path::new("src/api.gen.rs"), false));
    }

    #[test]
    fn exclude_globs_match_as_plain_globset() {
        let (_dir, f) = filter_with(&[], &["**/*.min.js", "vendor/**"], false);
        assert!(f.is_excluded(Path::new("assets/app.min.js"), false));
        assert!(f.is_excluded(Path::new("vendor/lib/x.c"), false));
        assert!(!f.is_excluded(Path::new("src/app.js"), false));
    }

    #[test]
    fn git_metadata_is_only_the_top_level_git_directory() {
        assert!(is_git_metadata(Path::new(".git/config")));
        assert!(is_git_metadata(Path::new(".git/objects/ab/cdef")));
        // `.gitignore` starts with `.git` as a *string* but is a different
        // first component; a nested `.git` under a vendored tree is not
        // this repository's metadata.
        assert!(!is_git_metadata(Path::new(".gitignore")));
        assert!(!is_git_metadata(Path::new("vendor/.git/config")));
    }
}