spec-driven-docs 0.4.10

//! Where an instance keeps the documents the gates read.
//!
//! The documentation root comes from the manifest when one exists, is
//! discovered from the conventional layouts when none does, and defaults to
//! `_docs`. Known-issue roots follow the same ladder, and explicit arguments
//! win over all of it — a repository keeping records outside the root passes
//! the directories holding them. Nothing here judges content; that is each
//! gate's business.

use camino::{Utf8Path, Utf8PathBuf};

use crate::domain::manifest::MANIFEST_PATH;
use crate::gates::{GateCtx, GateError};

/// The instance's documentation root, relative to the repository.
#[must_use]
pub fn docs_root(ctx: &GateCtx) -> Utf8PathBuf {
    if let Ok(text) = std::fs::read_to_string(ctx.path(MANIFEST_PATH))
        && let Ok(value) = serde_json::from_str::<serde_json::Value>(&text)
        && let Some(root) = value.get("docs_root").and_then(serde_json::Value::as_str)
        && !root.is_empty()
    {
        return Utf8PathBuf::from(root);
    }
    for candidate in ["_docs", "docs"] {
        if discovered(ctx, &Utf8Path::new(candidate).join("specs")) {
            return Utf8PathBuf::from(candidate);
        }
    }
    Utf8PathBuf::from("_docs")
}

/// The directories that may hold known-issue records, relative to the
/// repository. Arguments win; a manifest names one root; a bare consumer's
/// roots are discovered.
#[must_use]
pub fn ki_record_roots(ctx: &GateCtx, args: &[String]) -> Vec<Utf8PathBuf> {
    if !args.is_empty() {
        return args.iter().map(Utf8PathBuf::from).collect();
    }
    if ctx.path(MANIFEST_PATH).is_file() {
        return vec![docs_root(ctx).join("reference/known-issues")];
    }
    ["_docs", "docs"]
        .into_iter()
        .map(|candidate| Utf8Path::new(candidate).join("reference/known-issues"))
        .filter(|root| discovered(ctx, root))
        .collect()
}

/// Whether a discovered candidate is a directory the caller must read.
///
/// A candidate whose metadata cannot be read is kept rather than dropped.
/// `is_dir` answers false for a directory the process cannot stat, so
/// dropping it there would report an unreadable layout as a layout the
/// repository does not keep. Kept, it reaches the reader, which raises the
/// failure or reports the layout as moved rather than judging a tree it
/// never opened.
fn discovered(ctx: &GateCtx, root: &Utf8Path) -> bool {
    match std::fs::metadata(ctx.path(root)) {
        Ok(metadata) => metadata.is_dir(),
        Err(source) => source.kind() != std::io::ErrorKind::NotFound,
    }
}

/// Every known-issue record under the resolved roots, repository-relative.
///
/// A root that is not there is a zone the repository does not keep, and it
/// is skipped. Every other failure is raised: a directory the process
/// cannot read holds records this returns none of, and reporting that as an
/// empty zone would read as a clean review.
///
/// # Errors
///
/// [`crate::gates::GateError::Io`] when a present root cannot be listed.
pub fn ki_records(ctx: &GateCtx, args: &[String]) -> Result<Vec<Utf8PathBuf>, GateError> {
    let mut records = Vec::new();
    for root in ki_record_roots(ctx, args) {
        let entries = match ctx.path(&root).read_dir_utf8() {
            Ok(entries) => entries,
            Err(source) if source.kind() == std::io::ErrorKind::NotFound => continue,
            Err(source) => return Err(GateError::io(&root, source)),
        };
        let mut names = Vec::new();
        for entry in entries {
            let entry = entry.map_err(|source| GateError::io(&root, source))?;
            if !entry
                .file_type()
                .map_err(|source| GateError::io(&root, source))?
                .is_file()
            {
                continue;
            }
            let name = entry.file_name().to_string();
            if name
                .strip_prefix("KI-")
                .and_then(|rest| rest.strip_suffix(".md"))
                .is_some_and(|slug| !slug.is_empty())
            {
                names.push(name);
            }
        }
        names.sort();
        records.extend(names.into_iter().map(|name| root.join(name)));
    }
    Ok(records)
}

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

    fn ctx(dir: &tempfile::TempDir) -> GateCtx {
        GateCtx::new(dir.path().to_str().unwrap())
    }

    fn write(dir: &tempfile::TempDir, path: &str, text: &str) {
        let path = dir.path().join(path);
        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
        std::fs::write(path, text).unwrap();
    }

    #[test]
    fn manifest_root_wins() {
        let dir = tempfile::tempdir().unwrap();
        write(
            &dir,
            ".spec-driven-docs/manifest.json",
            "{\n  \"docs_root\": \"docs\"\n}\n",
        );
        assert_eq!(docs_root(&ctx(&dir)), "docs");
    }

    #[test]
    fn roots_are_discovered_without_a_manifest() {
        let dir = tempfile::tempdir().unwrap();
        write(&dir, "docs/specs/SPEC-sample.md", "# S\n");
        assert_eq!(docs_root(&ctx(&dir)), "docs");

        let both = tempfile::tempdir().unwrap();
        write(&both, "_docs/specs/SPEC-sample.md", "# S\n");
        write(&both, "docs/specs/SPEC-sample.md", "# S\n");
        assert_eq!(docs_root(&ctx(&both)), "_docs");

        let neither = tempfile::tempdir().unwrap();
        assert_eq!(docs_root(&ctx(&neither)), "_docs");
    }

    #[test]
    fn record_arguments_win_over_discovery() {
        let dir = tempfile::tempdir().unwrap();
        write(&dir, "docs/reference/known-issues/KI-real.md", "# R\n");
        let roots = ki_record_roots(&ctx(&dir), &["tests/fixtures".to_string()]);
        assert_eq!(roots, vec![Utf8PathBuf::from("tests/fixtures")]);
    }

    #[test]
    fn records_follow_the_manifest_root() {
        let dir = tempfile::tempdir().unwrap();
        write(
            &dir,
            ".spec-driven-docs/manifest.json",
            "{\n  \"docs_root\": \"docs\"\n}\n",
        );
        write(&dir, "docs/reference/known-issues/KI-vendor.md", "# V\n");
        write(&dir, "docs/reference/known-issues/KI-.md", "# empty slug\n");
        write(
            &dir,
            "docs/reference/known-issues/notes.md",
            "# not a record\n",
        );
        assert_eq!(
            ki_records(&ctx(&dir), &[]).unwrap(),
            vec![Utf8PathBuf::from(
                "docs/reference/known-issues/KI-vendor.md"
            )]
        );
    }

    #[test]
    fn bare_consumer_roots_are_discovered() {
        let dir = tempfile::tempdir().unwrap();
        write(&dir, "docs/reference/known-issues/KI-a.md", "# A\n");
        write(&dir, "docs/reference/known-issues/KI-b.md", "# B\n");
        assert_eq!(
            ki_records(&ctx(&dir), &[]).unwrap(),
            vec![
                Utf8PathBuf::from("docs/reference/known-issues/KI-a.md"),
                Utf8PathBuf::from("docs/reference/known-issues/KI-b.md"),
            ]
        );
    }

    #[test]
    fn an_unreadable_layout_is_not_read_as_an_absent_one() {
        let dir = tempfile::tempdir().unwrap();
        std::fs::create_dir_all(dir.path().join("docs/specs")).unwrap();
        assert_eq!(docs_root(&ctx(&dir)), "docs");

        let specs = dir.path().join("docs/specs");
        let mut mode = std::fs::metadata(&specs).unwrap().permissions();
        std::os::unix::fs::PermissionsExt::set_mode(&mut mode, 0o000);
        std::fs::set_permissions(dir.path().join("docs"), mode.clone()).unwrap();
        let resolved = docs_root(&ctx(&dir));
        std::os::unix::fs::PermissionsExt::set_mode(&mut mode, 0o755);
        std::fs::set_permissions(dir.path().join("docs"), mode).unwrap();
        assert_eq!(
            resolved, "docs",
            "an unreadable layout fell through to the default root"
        );
    }

    #[test]
    fn an_unsearchable_ancestor_is_raised_rather_than_discovered_away() {
        let dir = tempfile::tempdir().unwrap();
        std::fs::create_dir_all(dir.path().join("docs/reference/known-issues")).unwrap();
        let ancestor = dir.path().join("docs/reference");
        let mut mode = std::fs::metadata(&ancestor).unwrap().permissions();
        std::os::unix::fs::PermissionsExt::set_mode(&mut mode, 0o000);
        std::fs::set_permissions(&ancestor, mode.clone()).unwrap();
        let raised = ki_records(&ctx(&dir), &[]).is_err();
        std::os::unix::fs::PermissionsExt::set_mode(&mut mode, 0o755);
        std::fs::set_permissions(&ancestor, mode).unwrap();
        assert!(raised, "an unsearchable ancestor listed as no zone");
    }

    #[test]
    fn an_absent_zone_is_skipped_and_an_unreadable_one_is_raised() {
        let dir = tempfile::tempdir().unwrap();
        write(&dir, "docs/specs/SPEC-a.md", "# A\n");
        assert!(ki_records(&ctx(&dir), &[]).unwrap().is_empty());

        let zone = dir.path().join("docs/reference/known-issues");
        std::fs::create_dir_all(&zone).unwrap();
        let mut mode = std::fs::metadata(&zone).unwrap().permissions();
        std::os::unix::fs::PermissionsExt::set_mode(&mut mode, 0o000);
        std::fs::set_permissions(&zone, mode.clone()).unwrap();
        let raised = ki_records(&ctx(&dir), &[]).is_err();
        std::os::unix::fs::PermissionsExt::set_mode(&mut mode, 0o755);
        std::fs::set_permissions(&zone, mode).unwrap();
        assert!(raised, "an unreadable zone listed as empty");
    }
}