json-cursor 0.1.0

A strict JSON pull cursor over bytes: each key and value in order, strings borrowed when they have no escapes, and every number's exact text, with every byte checked against RFC 8259. No dependencies, no unsafe code, no_std.
Documentation 
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//! JSONTestSuite's parsing cases (tests/JSONTestSuite, see NOTICE): every `y_` file is accepted,
//! every `n_` file refused, and each `i_` file, which RFC 8259 leaves to the implementation, gets
//! the choice pinned below.

use std::path::Path;

/// The `i_` files the cursor accepts: numbers past a double's range, still in JSON's grammar, whose
/// text it gives as written. Every other `i_` file is refused: bytes that are not UTF-8, half of a
/// surrogate pair, a byte-order mark, or 500 nested arrays, past the skip's depth limit of 128.
const ACCEPTED: [&str; 10] = [
    "i_number_double_huge_neg_exp.json",
    "i_number_huge_exp.json",
    "i_number_neg_int_huge_exp.json",
    "i_number_pos_double_huge_exp.json",
    "i_number_real_neg_overflow.json",
    "i_number_real_pos_overflow.json",
    "i_number_real_underflow.json",
    "i_number_too_big_neg_int.json",
    "i_number_too_big_pos_int.json",
    "i_number_very_big_negative_int.json",
];

#[test]
fn every_case_of_json_test_suite_gets_its_answer() {
    let dir = Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/JSONTestSuite/test_parsing");
    let mut wrong = Vec::new();
    let mut counts = [0usize; 3];
    for entry in std::fs::read_dir(&dir).expect("the vendored corpus") {
        let path = entry.unwrap().path();
        let name = path.file_name().unwrap().to_str().unwrap().to_string();
        let accepted = json_cursor::validate(&std::fs::read(&path).unwrap()).is_ok();
        let want = match &name[..2] {
            "y_" => {
                counts[0] += 1;
                true
            }
            "n_" => {
                counts[1] += 1;
                false
            }
            "i_" => {
                counts[2] += 1;
                ACCEPTED.contains(&name.as_str())
            }
            _ => continue,
        };
        if accepted != want {
            wrong.push(format!("{name}: {}", if accepted { "accepted" } else { "refused" }));
        }
    }
    assert_eq!(counts, [95, 188, 35], "the whole corpus is there");
    wrong.sort();
    assert!(
        wrong.is_empty(),
        "{} cases answered otherwise:\n{}",
        wrong.len(),
        wrong.join("\n")
    );
}