{
    "title": "JSON Data Quality Error Catalog",
    "updated": "2026-08-06",
    "methodology": "The catalog separates parser errors, schema errors, encoding errors, and semantic contract failures.",
    "limitations": "Exact messages vary by language, parser, schema system, and runtime.",
    "columns": [
        "Error class",
        "Example signal",
        "Detection",
        "Repair principle"
    ],
    "rows": [
        [
            "Trailing comma",
            "Unexpected token before } or ]",
            "Parser",
            "Remove unsupported trailing delimiter"
        ],
        [
            "Single quotes",
            "Strings use apostrophes",
            "Parser",
            "Use double-quoted JSON strings"
        ],
        [
            "Unquoted key",
            "{name:\"A\"}",
            "Parser",
            "Quote property names"
        ],
        [
            "Comment",
            "// note",
            "Parser",
            "Move comments outside JSON or use supported format"
        ],
        [
            "Duplicate key",
            "Same key twice",
            "Schema/linter",
            "Define unique keys and resolve conflict"
        ],
        [
            "Wrong type",
            "\"42\" instead of 42",
            "Schema",
            "Normalize producer or validation"
        ],
        [
            "Null ambiguity",
            "null means unknown or empty",
            "Data contract",
            "Document semantic meaning"
        ],
        [
            "Date ambiguity",
            "03/04/26",
            "Schema/business rule",
            "Use documented ISO-style representation"
        ],
        [
            "Unsafe integer",
            "Very large ID becomes rounded",
            "Runtime test",
            "Represent identifiers safely"
        ],
        [
            "NaN/Infinity",
            "Non-JSON numeric values",
            "Parser",
            "Use null/string/error contract"
        ],
        [
            "Encoding",
            "Invalid UTF-8",
            "Byte validation",
            "Normalize encoding"
        ],
        [
            "Control character",
            "Raw newline in string",
            "Parser",
            "Escape characters"
        ],
        [
            "Root mismatch",
            "Array expected, object received",
            "Schema",
            "Align contract"
        ],
        [
            "Required field",
            "Key absent",
            "Schema",
            "Supply or revise requirement"
        ],
        [
            "Enum mismatch",
            "Unexpected status value",
            "Schema",
            "Use allowed vocabulary"
        ],
        [
            "Circular source object",
            "Serializer fails",
            "Runtime",
            "Remove cycle or define reference model"
        ]
    ]
}