vectorcraft/crates/testkit/src/lib.rs

//! VectorCraft test helpers.
//!
//! - [`fixtures`]: sessions and documents in known states (empty, single/multi selection, a "rich"
//!   document touching most node kinds), plus a [`fixtures::DocBuilder`] for building documents
//!   directly (render tests).
//! - [`strategies`]: proptest strategies for geometry and for engine command sequences ([`strategies::Op`]), and
//!   junk-parameter generators for fuzzing the command registry.
//! - [`invariants`]: structural checks for documents and sessions, and round-trip checks
//!   (`.vectorcraft`, SVG, `document.inspect`).
//! - [`raster`]: rendering helpers and image comparison with a perceptual tolerance.
//! - [`geom`]: geometry assertions (approximate equality, curve sampling, Hausdorff distance).
//! - [`pdf`]: hand-written PDF files (page boxes, colour spaces, encryption) for import tests.
//! - [`ai`]: hand-written Illustrator editing data, and the EPS and `.ai` files that carry it.
//! - [`ase`]: hand-written swatch exchange (`.ase`) files for swatch library tests.
//! - [`tiff`]: hand-written TIFF files, chunky or planar, or compressed with CCITT Group 3, for
//!   image import tests.
//! - [`fonts`]: font files made from the bundled fonts (a renamed family) for font tests.
//!
//! This crate may only be used as a dev-dependency (enforced by `cargo xtask layers`).
// Test support only (a dev-dependency of every crate that uses it): a failed setup or assertion
// must panic, like `assert!`, so the shipped-code ban on panicking (AGENTS.md › Robustness) doesn't
// apply here.
#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
#![forbid(unsafe_code)]

pub mod ai;
pub mod ase;
pub mod fixtures;
pub mod fonts;
pub mod geom;
pub mod invariants;
pub mod pdf;
pub mod raster;
pub mod strategies;
pub mod tiff;

pub use serde_json::{Value, json};
pub use vectorcraft_engine::{Session, doc::NodeId};
/// Re-exports so dependents without direct dependencies (e.g. app test crates) can use them.
pub use {vectorcraft_doc as doc, vectorcraft_format as format, vectorcraft_render as render, vectorcraft_svg as svg};

/// A per-process temporary directory for test output (created on first use). It is made with
/// `create_dir` (owner-only on Unix), and a directory that already exists is reused only when it is
/// a real directory, not a link, with no access for others and owned by this user: one pre-made in
/// a shared temp folder is refused.
/// The first call for a `tag` in a process empties a directory left by an earlier process of the
/// same id (Windows reuses ids soon); later calls share it.
pub fn temp_dir(tag: &str) -> std::path::PathBuf {
    static SEEN: std::sync::Mutex<std::collections::BTreeSet<String>> = std::sync::Mutex::new(std::collections::BTreeSet::new());
    // Held to the end: another thread's first files must not land before the emptying.
    let mut seen = SEEN.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
    let first = seen.insert(tag.to_string());
    let dir = std::env::temp_dir().join(format!("vectorcraft-testkit-{tag}-{}", std::process::id()));
    // Unix sets the mode on it; elsewhere it stays as made.
    #[cfg_attr(not(unix), allow(unused_mut))]
    let mut b = std::fs::DirBuilder::new();
    #[cfg(unix)]
    std::os::unix::fs::DirBuilderExt::mode(&mut b, 0o700);
    if let Err(e) = b.create(&dir) {
        let m = std::fs::symlink_metadata(&dir).expect("temp dir");
        assert!(e.kind() == std::io::ErrorKind::AlreadyExists && m.is_dir(), "create temp dir: {e}");
        #[cfg(unix)]
        assert!(std::os::unix::fs::PermissionsExt::mode(&m.permissions()) & 0o077 == 0, "{}: not private", dir.display());
        // A directory made by another user may pass the mode check now and be opened up later: a
        // probe file made new (never through a link left in its place) is this user's, and the
        // directory must belong to the same user.
        // Named for this call: tests running alongside probe the same directory.
        static PROBES: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
        let probe = dir.join(format!(".probe-{}", PROBES.fetch_add(1, std::sync::atomic::Ordering::Relaxed)));
        let made = std::fs::OpenOptions::new().write(true).create_new(true).open(&probe).and_then(|f| f.metadata());
        let _ = std::fs::remove_file(&probe);
        let made = made.unwrap_or_else(|e| panic!("{}: not owned by this user ({e})", dir.display()));
        #[cfg(unix)]
        assert_eq!(std::os::unix::fs::MetadataExt::uid(&made), std::os::unix::fs::MetadataExt::uid(&m), "{}: not owned by this user", dir.display());
        #[cfg(not(unix))]
        let _ = made;
        if first {
            for entry in std::fs::read_dir(&dir).expect("temp dir").flatten() {
                let path = entry.path();
                let gone = if path.is_dir() { std::fs::remove_dir_all(&path) } else { std::fs::remove_file(&path) };
                assert!(gone.is_ok(), "{}: left by an earlier run", path.display());
            }
        }
    }
    dir
}

/// A test's own temporary directory, removed with everything in it when dropped, also when the
/// test panics. [`temp_dir`] makes it, with the same checks, under a tag no other `TempDir` in this
/// process uses, so tests running alongside never share one. A removal that fails (a file still
/// held open) is ignored; the next process with the same id empties the directory before use.
pub struct TempDir(std::path::PathBuf);

impl TempDir {
    /// A new empty directory `vectorcraft-testkit-<tag>-<n>-<process id>` in the system temporary
    /// folder, where `n` counts the `TempDir`s made in this process.
    pub fn new(tag: &str) -> Self {
        static NEXT: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
        let n = NEXT.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
        Self(temp_dir(&format!("{tag}-{n}")))
    }
}

impl std::ops::Deref for TempDir {
    type Target = std::path::PathBuf;
    fn deref(&self) -> &std::path::PathBuf {
        &self.0
    }
}

impl AsRef<std::path::Path> for TempDir {
    fn as_ref(&self) -> &std::path::Path {
        &self.0
    }
}

impl Drop for TempDir {
    fn drop(&mut self) {
        let _ = std::fs::remove_dir_all(&self.0);
    }
}

/// How many shapes an SVG draws: its `<path>` elements and the basic shapes SVG export writes
/// simple shapes as (`<rect>`, `<circle>`, `<ellipse>`, `<line>`, `<polyline>`, `<polygon>`).
pub fn svg_shapes(svg: &str) -> usize {
    ["<path", "<rect", "<circle", "<ellipse", "<line ", "<polyline", "<polygon"].iter().map(|t| svg.matches(t).count()).sum()
}

thread_local! {
    static QUIET: std::cell::Cell<bool> = const { std::cell::Cell::new(false) };
}

/// Run `f`, catching a panic without printing it (other threads' panics still print). Returns the
/// panic message on panic.
pub fn catch_quiet<T>(f: impl FnOnce() -> T) -> Result<T, String> {
    static HOOK: std::sync::Once = std::sync::Once::new();
    HOOK.call_once(|| {
        let prev = std::panic::take_hook();
        std::panic::set_hook(Box::new(move |info| {
            if !QUIET.with(|q| q.get()) {
                prev(info);
            }
        }));
    });
    QUIET.with(|q| q.set(true));
    let r = std::panic::catch_unwind(std::panic::AssertUnwindSafe(f));
    QUIET.with(|q| q.set(false));
    r.map_err(|p| p.downcast_ref::<String>().cloned().or_else(|| p.downcast_ref::<&str>().map(|s| s.to_string())).unwrap_or_else(|| "panic".into()))
}

#[cfg(test)]
mod tests {
    #[test]
    fn a_temp_dir_starts_empty_in_a_process_and_stays_for_later_calls() {
        let tag = "fresh-temp-dir";
        let left = std::env::temp_dir().join(format!("vectorcraft-testkit-{tag}-{}", std::process::id()));
        // Made private, as `temp_dir` makes it: a directory others can reach is refused, not reused.
        #[cfg_attr(not(unix), allow(unused_mut))]
        let mut b = std::fs::DirBuilder::new();
        b.recursive(true);
        #[cfg(unix)]
        std::os::unix::fs::DirBuilderExt::mode(&mut b, 0o700);
        b.create(left.join("nested")).unwrap();
        std::fs::write(left.join("left.txt"), b"an earlier process").unwrap();
        let dir = super::temp_dir(tag);
        assert_eq!(dir, left);
        assert_eq!(std::fs::read_dir(&dir).unwrap().count(), 0, "what an earlier process of this id left is gone");
        std::fs::write(dir.join("mine.txt"), b"this process").unwrap();
        assert!(super::temp_dir(tag).join("mine.txt").is_file(), "a later call keeps this process's files");
        std::fs::remove_dir_all(&dir).unwrap();
    }

    #[test]
    fn a_test_dir_is_removed_with_its_contents_when_dropped() {
        let dir = super::TempDir::new("dropped");
        let path = dir.to_path_buf();
        std::fs::create_dir_all(path.join("nested")).unwrap();
        std::fs::write(path.join("nested").join("a.txt"), b"a").unwrap();
        drop(dir);
        assert!(!path.exists(), "{} is left", path.display());
    }

    #[test]
    fn a_test_dir_is_removed_when_its_test_panics() {
        let mut path = None;
        let r = super::catch_quiet::<()>(|| {
            let dir = super::TempDir::new("panicked");
            std::fs::write(dir.join("a.txt"), b"a").unwrap();
            path = Some(dir.to_path_buf());
            panic!("the test fails");
        });
        assert_eq!(r.err().as_deref(), Some("the test fails"));
        let path = path.unwrap();
        assert!(!path.exists(), "{} is left", path.display());
    }

    #[test]
    fn test_dirs_with_one_tag_are_separate_and_private() {
        let (a, b) = (super::TempDir::new("shared-tag"), super::TempDir::new("shared-tag"));
        assert_ne!(*a, *b);
        std::fs::write(a.join("a.txt"), b"a").unwrap();
        assert_eq!(std::fs::read_dir(&*b).unwrap().count(), 0, "one test's files are not in another's directory");
        #[cfg(unix)]
        assert_eq!(std::os::unix::fs::PermissionsExt::mode(&std::fs::metadata(&*a).unwrap().permissions()) & 0o777, 0o700);
        drop(a);
        assert!(b.is_dir(), "dropping one leaves the other");
    }
}