nornir 0.4.10

//! Test inventory — enumerate a repo's tests grouped by the **Rust-standard**
//! categories so the `tests` doc section can list them without hand-authoring:
//!
//! - **unit** — `#[test]` / `#[tokio::test]` (any `…::test`) fns under `src/`;
//! - **integration** — the same, under `tests/`;
//! - **doc** — runnable ```` ``` ```` code fences in `///` / `//!` doc comments.
//!
//! Source of truth is the crate sources parsed with `syn` (already a dep), so
//! the inventory stays correct as tests come and go.

use std::path::Path;

use walkdir::WalkDir;

/// Tests found in one `.rs` file (unit or integration).
#[derive(Debug, Clone)]
pub struct FileTests {
    /// Repo-root-relative path.
    pub file: String,
    /// `#[test]`/`#[tokio::test]` fn names, in source order.
    pub tests: Vec<String>,
}

/// Doc-tests found in one `.rs` file.
#[derive(Debug, Clone)]
pub struct FileDocTests {
    pub file: String,
    /// Count of runnable doc-test code fences.
    pub count: usize,
}

/// The whole inventory for a repo.
#[derive(Debug, Default, Clone)]
pub struct TestInventory {
    pub unit: Vec<FileTests>,
    pub integration: Vec<FileTests>,
    pub doc: Vec<FileDocTests>,
}

impl TestInventory {
    pub fn unit_total(&self) -> usize {
        self.unit.iter().map(|f| f.tests.len()).sum()
    }
    pub fn integration_total(&self) -> usize {
        self.integration.iter().map(|f| f.tests.len()).sum()
    }
    pub fn doc_total(&self) -> usize {
        self.doc.iter().map(|f| f.count).sum()
    }
}

/// True if a `.rs` file (by stem) is really a **performance benchmark** rather
/// than a correctness test — these often live as `#[test]` fns (so `cargo test`
/// runs them) but measure throughput and print MB/s. Counting them as tests
/// inflates the test inventory and double-represents work that belongs in a
/// `benches` section. Skipped by default; `tests include_benches=true` keeps them.
pub fn is_benchmark_file(stem: &str) -> bool {
    let s = stem.to_ascii_lowercase();
    s.ends_with("_bench")
        || s.ends_with("_benches")
        || s.starts_with("perf_")
        || s.starts_with("bench_")
        || s.contains("throughput")
        || s.contains("benchmark")
}

/// Walk every crate under `repo_root` (optionally filtered to crate names
/// containing `crate_filter`) and collect its test inventory. When
/// `include_benches` is false (the default), files whose name marks them as
/// performance benchmarks (see [`is_benchmark_file`]) are skipped.
pub fn scan(repo_root: &Path, crate_filter: Option<&str>) -> TestInventory {
    scan_opts(repo_root, crate_filter, false)
}

pub fn scan_opts(repo_root: &Path, crate_filter: Option<&str>, include_benches: bool) -> TestInventory {
    let mut inv = TestInventory::default();
    for entry in WalkDir::new(repo_root)
        .into_iter()
        .filter_entry(|e| !is_skipped_dir(&e.file_name().to_string_lossy()))
        .flatten()
    {
        if entry.file_name() != "Cargo.toml" {
            continue;
        }
        let Ok(text) = std::fs::read_to_string(entry.path()) else { continue };
        let Ok(doc) = text.parse::<toml::Value>() else { continue };
        let Some(crate_name) = doc
            .get("package")
            .and_then(|p| p.get("name"))
            .and_then(|n| n.as_str())
        else {
            continue;
        };
        if let Some(pat) = crate_filter {
            if !crate_name.contains(pat) {
                continue;
            }
        }
        let Some(crate_dir) = entry.path().parent() else { continue };
        scan_crate(repo_root, crate_dir, &mut inv, include_benches);
    }
    inv.unit.sort_by(|a, b| a.file.cmp(&b.file));
    inv.integration.sort_by(|a, b| a.file.cmp(&b.file));
    inv.doc.sort_by(|a, b| a.file.cmp(&b.file));
    inv
}

fn scan_crate(repo_root: &Path, crate_dir: &Path, inv: &mut TestInventory, include_benches: bool) {
    // unit (src/) + integration (tests/); doc-tests come from src/.
    for (sub, integration) in [("src", false), ("tests", true)] {
        let dir = crate_dir.join(sub);
        if !dir.is_dir() {
            continue;
        }
        for entry in WalkDir::new(&dir)
            .into_iter()
            .filter_entry(|e| !is_skipped_dir(&e.file_name().to_string_lossy()))
            .flatten()
        {
            let path = entry.path();
            if !entry.file_type().is_file()
                || path.extension().and_then(|e| e.to_str()) != Some("rs")
            {
                continue;
            }
            // Skip performance-benchmark files (they belong in a benches section,
            // not the test count) unless explicitly included.
            if !include_benches {
                if let Some(stem) = path.file_stem().and_then(|s| s.to_str()) {
                    if is_benchmark_file(stem) {
                        continue;
                    }
                }
            }
            let Ok(src) = std::fs::read_to_string(path) else { continue };
            let rel = rel_path(repo_root, path);

            let names = test_fn_names(&src);
            if !names.is_empty() {
                let ft = FileTests { file: rel.clone(), tests: names };
                if integration {
                    inv.integration.push(ft);
                } else {
                    inv.unit.push(ft);
                }
            }
            // Doc-tests only counted from library/source files.
            if !integration {
                let count = count_doc_tests(&src);
                if count > 0 {
                    inv.doc.push(FileDocTests { file: rel, count });
                }
            }
        }
    }
}

fn rel_path(repo_root: &Path, path: &Path) -> String {
    path.strip_prefix(repo_root)
        .unwrap_or(path)
        .to_string_lossy()
        .replace('\\', "/")
}

/// Names of `#[test]`/`#[tokio::test]`-attributed fns (any attribute whose last
/// path segment is `test`), recursing into nested modules. `#[bench]` is *not*
/// a test and is excluded.
fn test_fn_names(src: &str) -> Vec<String> {
    use syn::visit::{self, Visit};

    struct Collector {
        names: Vec<String>,
    }
    impl<'ast> Visit<'ast> for Collector {
        fn visit_item_fn(&mut self, f: &'ast syn::ItemFn) {
            if has_test_attr(&f.attrs) {
                self.names.push(f.sig.ident.to_string());
            }
            visit::visit_item_fn(self, f);
        }
    }
    fn has_test_attr(attrs: &[syn::Attribute]) -> bool {
        attrs.iter().any(|a| {
            a.path()
                .segments
                .last()
                .is_some_and(|s| s.ident == "test")
        })
    }

    let Ok(file) = syn::parse_file(src) else { return Vec::new() };
    let mut c = Collector { names: Vec::new() };
    c.visit_file(&file);
    c.names
}

/// Count runnable doc-test code fences in `///` / `//!` comments. A fence whose
/// info string marks it non-runnable (`ignore`, `text`) is skipped; everything
/// else (empty, `rust`, `no_run`, `should_panic`, `compile_fail`, …) counts.
fn count_doc_tests(src: &str) -> usize {
    let mut count = 0;
    let mut in_fence = false;
    for raw in src.lines() {
        let line = raw.trim_start();
        let Some(doc) = line
            .strip_prefix("///")
            .or_else(|| line.strip_prefix("//!"))
        else {
            continue;
        };
        let doc = doc.trim_start();
        let Some(info) = doc.strip_prefix("```").or_else(|| doc.strip_prefix("~~~")) else {
            continue;
        };
        if in_fence {
            in_fence = false; // closing fence
            continue;
        }
        in_fence = true;
        let info = info.trim().to_ascii_lowercase();
        let non_runnable = info.split([',', ' ']).any(|t| t == "ignore" || t == "text");
        if !non_runnable {
            count += 1;
        }
    }
    count
}

fn is_skipped_dir(name: &str) -> bool {
    matches!(name, "target" | ".git" | "node_modules" | ".nornir")
}

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

    fn write(p: &Path, s: &str) {
        std::fs::create_dir_all(p.parent().unwrap()).unwrap();
        std::fs::write(p, s).unwrap();
    }

    #[test]
    fn scans_unit_integration_and_doc() {
        let t = tempfile::tempdir().unwrap();
        let root = t.path();
        write(&root.join("Cargo.toml"), "[package]\nname='demo'\nversion='0.1.0'\n");
        write(
            &root.join("src/lib.rs"),
            r#"
/// Adds.
/// ```
/// assert_eq!(demo::add(1,2), 3);
/// ```
/// ```ignore
/// not_run();
/// ```
pub fn add(a: i32, b: i32) -> i32 { a + b }

#[cfg(test)]
mod tests {
    #[test]
    fn unit_a() {}
    #[tokio::test]
    async fn unit_b() {}
    #[bench]
    fn not_a_test() {}
}
"#,
        );
        write(
            &root.join("tests/it.rs"),
            "#[test]\nfn integration_one() {}\n",
        );

        let inv = scan(root, None);
        assert_eq!(inv.unit_total(), 2, "unit: {:?}", inv.unit);
        assert_eq!(inv.integration_total(), 1);
        assert_eq!(inv.doc_total(), 1, "only the runnable fence counts");
        assert!(inv.unit[0].tests.contains(&"unit_a".to_string()));
        assert!(!inv.unit[0].tests.contains(&"not_a_test".to_string()));
    }

    #[test]
    fn skips_benchmark_files_by_default() {
        let t = tempfile::tempdir().unwrap();
        let root = t.path();
        write(&root.join("Cargo.toml"), "[package]\nname='demo'\nversion='0.1.0'\n");
        write(&root.join("tests/integration_test.rs"), "#[test]\nfn real_one() {}\n");
        write(&root.join("tests/compress_dir_bench.rs"), "#[test]\nfn compress_dir_real_jars() {}\n");
        write(&root.join("tests/perf_bench.rs"), "#[test]\nfn perf_suite() {}\n");

        // default: bench files excluded
        let inv = scan(root, None);
        assert_eq!(inv.integration_total(), 1, "only the real test counts: {:?}", inv.integration);
        assert_eq!(inv.integration[0].file, "tests/integration_test.rs");

        // include_benches=true brings them back
        let inv2 = scan_opts(root, None, true);
        assert_eq!(inv2.integration_total(), 3);
    }

    #[test]
    fn benchmark_file_classifier() {
        assert!(is_benchmark_file("compress_dir_bench"));
        assert!(is_benchmark_file("perf_bench"));
        assert!(is_benchmark_file("maven_bench"));
        assert!(is_benchmark_file("jar_throughput"));
        assert!(is_benchmark_file("decompress_benchmark"));
        assert!(!is_benchmark_file("integration_test"));
        assert!(!is_benchmark_file("maven_artifacts"));
        assert!(!is_benchmark_file("codec"));
    }

    #[test]
    fn crate_filter_limits_scope() {
        let t = tempfile::tempdir().unwrap();
        let root = t.path();
        write(&root.join("a/Cargo.toml"), "[package]\nname='alpha'\nversion='0.1.0'\n");
        write(&root.join("a/src/lib.rs"), "#[test]\nfn ta() {}\n");
        write(&root.join("b/Cargo.toml"), "[package]\nname='beta'\nversion='0.1.0'\n");
        write(&root.join("b/src/lib.rs"), "#[test]\nfn tb() {}\n");
        let inv = scan(root, Some("alph"));
        assert_eq!(inv.unit_total(), 1);
        assert_eq!(inv.unit[0].file, "a/src/lib.rs");
    }
}