vectorcraft/crates/format/tests/prop_format.rs

//! `.vectorcraft` format: round trips, robustness against garbage, versioning, unknown fields.
// Integration tests: unwrapping and panicking on failure is fine here, unlike in shipped code (AGENTS.md › Robustness).
#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]

use proptest::prelude::*;
use serde_json::{Value, json};
use vectorcraft_doc::{Document, ImageBlob, ImageObject, Node, NodeId, NodeKind};
use vectorcraft_format::{SaveOptions, base64_decode, base64_encode, load, preview, save, save_with, sniff};
use vectorcraft_geom::Affine;
use vectorcraft_testkit::fixtures;
use vectorcraft_testkit::invariants::{check_document, check_native_roundtrip, check_native_roundtrip_exact, doc_json, json_approx_eq};
use vectorcraft_testkit::strategies::arb_ops;

fn rich_doc() -> Document {
    (*fixtures::rich_session().doc().unwrap().doc).clone()
}

proptest! {
    #![proptest_config(ProptestConfig { cases: 128, failure_persistence: None, ..ProptestConfig::default() })]

    #[test]
    fn base64_roundtrip(data in prop::collection::vec(any::<u8>(), 0..300)) {
        let s = base64_encode(&data);
        prop_assert_eq!(s.len() % 4, 0);
        prop_assert_eq!(base64_decode(&s), Some(data.clone()));
        // Whitespace is ignored.
        let spaced: String = s.chars().flat_map(|c| [c, '\n']).collect();
        prop_assert_eq!(base64_decode(&spaced), Some(data));
    }

    #[test]
    fn base64_decode_never_panics(s in ".{0,64}") {
        let _ = base64_decode(&s);
    }

    /// Arbitrary bytes are rejected (or, if they happen to parse, yield a valid document) — never a panic.
    #[test]
    fn load_garbage_never_panics(bytes in prop::collection::vec(any::<u8>(), 0..512)) {
        if let Ok(d) = load(&bytes) {
            check_document(&d).map_err(TestCaseError::fail)?;
        }
    }

    /// Mutating a valid file (byte flips / truncation) never panics the loader.
    #[test]
    fn load_mutated_file_never_panics(cut in 0usize..4000, flips in prop::collection::vec((0usize..4000, any::<u8>()), 0..8)) {
        let mut bytes = save(&Document::new(100.0, 100.0), false);
        for (i, b) in flips {
            let n = bytes.len();
            bytes[i % n] = b;
        }
        bytes.truncate(cut.min(bytes.len()));
        let _ = load(&bytes);
    }

    /// Documents produced by random editing survive save → load (numbers to 1e-12).
    #[test]
    fn random_documents_roundtrip(ops in arb_ops(5..40)) {
        let mut s = fixtures::session();
        for op in &ops {
            let _ = op.apply(&mut s);
        }
        let d = s.doc().unwrap().doc.clone();
        check_native_roundtrip(&d).map_err(TestCaseError::fail)?;
        // Pretty and compact encodings load to the same document.
        let a = doc_json(&load(&save(&d, true)).unwrap());
        let b = doc_json(&load(&save(&d, false)).unwrap());
        prop_assert_eq!(a, b);
    }

    /// Embedded image bytes survive the base64 round trip exactly (saves keep the images in use).
    #[test]
    fn images_roundtrip(data in prop::collection::vec(any::<u8>(), 0..2000), key in "[a-z \"\\\\]{1,8}") {
        let mut d = Document::new(10.0, 10.0);
        d.images.insert(key.clone(), ImageBlob::new("image/png", data.clone()));
        let layer = d.layers[0].id;
        let id = d.alloc_id();
        let im = ImageObject { key: key.clone(), width: 1, height: 1, xf: Affine::IDENTITY, link: None };
        d.insert(Some(layer), 0, Node::new(id, NodeKind::Image(im))).unwrap();
        for pretty in [false, true] {
            let back = load(&save(&d, pretty)).unwrap();
            prop_assert_eq!(back.images.get(&key).map(|b| b.bytes.as_ref().clone()), Some(data.clone()));
        }
    }

    /// Compressed and older-version saves of random documents load to the same document.
    #[test]
    fn compressed_and_older_saves_roundtrip(ops in arb_ops(5..30)) {
        let mut s = fixtures::session();
        for op in &ops {
            let _ = op.apply(&mut s);
        }
        let d = s.doc().unwrap().doc.clone();
        let want = doc_json(&load(&save(&d, false)).unwrap());
        for o in [SaveOptions { compress: true, ..SaveOptions::default() }, SaveOptions { version: 2, ..SaveOptions::default() }, SaveOptions { version: 1, pretty: true, ..SaveOptions::default() }] {
            let back = load(&save_with(&d, &o).unwrap()).unwrap();
            prop_assert!(json_approx_eq(&doc_json(&back), &want, 1e-12), "{:?} differs", o);
        }
    }

    /// Mutating a compressed file (byte flips / truncation) never panics the loader or the sniffer.
    #[test]
    fn load_mutated_compressed_file_never_panics(cut in 0usize..2000, flips in prop::collection::vec((0usize..2000, any::<u8>()), 0..8)) {
        let mut bytes = save_with(&Document::new(100.0, 100.0), &SaveOptions { compress: true, ..SaveOptions::default() }).unwrap();
        for (i, b) in flips {
            let n = bytes.len();
            bytes[i % n] = b;
        }
        bytes.truncate(cut.min(bytes.len()));
        let _ = sniff(&bytes);
        let _ = preview(&bytes);
        if let Ok(d) = load(&bytes) {
            check_document(&d).map_err(TestCaseError::fail)?;
        }
    }
}

#[test]
fn rich_document_roundtrips() {
    let d = rich_doc();
    check_native_roundtrip(&d).unwrap();
    let bytes = save(&d, true);
    assert!(sniff(&bytes));
    let v: Value = serde_json::from_slice(&bytes).unwrap();
    assert_eq!(v["format"], "vectorcraft");
    assert_eq!(v["version"], vectorcraft_format::VERSION);
}

#[test]
fn sniff_distinguishes_formats() {
    assert!(sniff(&save(&Document::new(1.0, 1.0), false)));
    assert!(!sniff(b"<svg xmlns=\"http://www.w3.org/2000/svg\"/>"));
    assert!(!sniff(b"%PDF-1.7"));
    assert!(!sniff(b""));
    assert!(!sniff(&[0xff, 0xfe, 0x00]));
}

#[test]
fn rejects_newer_versions_and_other_formats() {
    let mut v: Value = serde_json::from_slice(&save(&Document::new(1.0, 1.0), false)).unwrap();
    v["version"] = json!(vectorcraft_format::VERSION + 1);
    assert!(matches!(load(&serde_json::to_vec(&v).unwrap()), Err(vectorcraft_format::FormatError::TooNew(_))));
    v["version"] = json!(vectorcraft_format::VERSION);
    v["format"] = json!("other");
    assert!(matches!(load(&serde_json::to_vec(&v).unwrap()), Err(vectorcraft_format::FormatError::NotVectorcraft(_))));
    v["format"] = json!("vectorcraft");
    v["images"] = json!({"x": {"mime": "image/png", "data": "not base64!"}});
    assert!(matches!(load(&serde_json::to_vec(&v).unwrap()), Err(vectorcraft_format::FormatError::BadImage(_))));
}

#[test]
fn unknown_fields_are_preserved() {
    let mut v: Value = serde_json::from_slice(&save(&Document::new(1.0, 1.0), false)).unwrap();
    v["document"]["unknown"] = json!({"futureFeature": {"a": [1, 2, 3]}});
    let d = load(&serde_json::to_vec(&v).unwrap()).unwrap();
    let again: Value = serde_json::from_slice(&save(&d, false)).unwrap();
    assert_eq!(again["document"]["unknown"]["futureFeature"]["a"], json!([1, 2, 3]));
}

#[test]
fn load_repairs_next_id() {
    let d = rich_doc();
    let mut v: Value = serde_json::from_slice(&save(&d, false)).unwrap();
    v["document"]["next_id"] = json!(1);
    let mut back = load(&serde_json::to_vec(&v).unwrap()).unwrap();
    check_document(&back).unwrap();
    let fresh = back.alloc_id();
    assert!(back.node(fresh).is_none(), "allocated id {fresh} collides");
    let max = fixtures::all_ids(&back).into_iter().map(|NodeId(i)| i).max().unwrap();
    assert!(fresh.0 > max);
}

#[test]
fn approx_equal_documents_compare_equal() {
    let d = rich_doc();
    assert!(json_approx_eq(&doc_json(&d), &doc_json(&d), 0.0));
}

#[test]
fn bug_f64_bit_exact_roundtrip() {
    check_native_roundtrip_exact(&rich_doc()).unwrap();
    let mut d = Document::new(126.86291501015239, 214.69463130731182);
    d.raster_effects_ppi = 0.1 + 0.2;
    check_native_roundtrip_exact(&d).unwrap();
}