module yaml

// JSON round-trip: parse_text() should accept any JSON document (YAML 1.2 is
// a JSON superset), and to_json() should produce a JSON document that
// re-parses to the same logical tree. This guards against regressions in
// either the parser's JSON-superset fast path or the serializer's escaping.

const json_corpus = [
    // scalars
    'true',
    'false',
    'null',
    '0',
    '-1',
    '1234567890',
    '3.14159',
    '1.5e-10',
    '""',
    '"hello"',
    '"with\\"quote"',
    '"with\\nnewline"',
    '"unicode: \\u00e9 \\u4e2d"',
    '"verbatim utf8: café 中"',
    // arrays
    '[]',
    '[1]',
    '[1,2,3]',
    '["a","b","c"]',
    '[null,true,false,1,1.5,"s"]',
    '[[1,2],[3,4],[]]',
    '[{"k":"v"},{"k":"w"}]',
    // objects
    '{}',
    '{"a":1}',
    '{"a":1,"b":2,"c":3}',
    '{"nested":{"deep":{"deeper":42}}}',
    '{"mixed":[1,{"k":"v"},null,true]}',
    '{"empty_arr":[],"empty_obj":{}}',
    '{"unicode_key_café":"value","quoted.key":"v2"}',
    // edge sizes
    '[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]',
    '{"a":1,"b":2,"c":3,"d":4,"e":5,"f":6,"g":7,"h":8,"i":9,"j":10}',
]!

fn test_json_corpus_roundtrip() ! {
    mut failed := []string{}
    for input in json_corpus {
        doc := parse_text(input) or {
            failed << 'parse error on ${input}: ${err}'
            continue
        }
        out := doc.to_json()
        eq := json_logically_eq(input, out) or {
            failed << '${input} -> ${out}: invalid JSON produced (${err})'
            continue
        }
        if !eq {
            failed << '${input} -> ${out}: not logically equal'
        }
    }
    if failed.len > 0 {
        eprintln('JSON round-trip failures (${failed.len}/${json_corpus.len}):')
        for f in failed {
            eprintln('  - ${f}')
        }
        assert false, '${failed.len} round-trip case(s) failed'
    }
}

// Anti-regression for the "first call works, repeated call breaks" family
// that used to surface in the json2.Any rebuild path: parse + to_json must
// be byte-stable across iterations on the same input. 500 iterations are
// enough to flush the original failure mode without bloating CI runtime.
fn test_json_roundtrip_is_idempotent_under_repetition() ! {
    src := '{"users":[{"id":1,"name":"alice","tags":["x","y"]},{"id":2,"name":"bob","tags":[]}],"meta":{"count":2,"page":null,"flags":{"a":true,"b":false}}}'
    mut prev := parse_text(src)!.to_json()
    for _ in 0 .. 500 {
        curr := parse_text(prev)!.to_json()
        assert curr == prev, 'round-trip drift detected'
        prev = curr
    }
}