PureXML/Sources/Parsing/ParseError.swift
Mihaela Mihaljevic 4ed8e9518a feat(parsing): first W3C-suite strictness pass; opt-in xmltest runner
Add five well-formedness checks the W3C xmltest suite surfaced: '--' inside
comments (also rejecting the ---> ending), raw '<' in attribute values, the
literal ]]> sequence in character data, attributes not separated by
whitespace, and characters outside the XML Char production in content, each
a located ParseError. The attribute scanners move to EventReaderAttributes
to stay under the type-body cap.

Add the opt-in W3C xmltest runner (XMLTS_ROOT-gated; the suite is never
vendored, James Clark's license permits redistribution only as the unmodified
archive; Foundation is used in this one test file for file access only).
Baseline: valid/sa 118/119, not-wf/sa 93/186 rejected (up from 80), the
remaining 93 carried as an exact known-deviations baseline so progress and
regressions are both visible. The two remaining leniency classes (internal-
subset DTD grammar, entity replacement-text well-formedness) are #120.

Part of #105 (Tier 2)
2026-06-10 04:59:39 +02:00

115 lines
5.8 KiB
Swift

public extension PureXML.Parsing {
/// Parser error with source position information when available.
enum ParseError: Swift.Error, Equatable, Sendable, CustomStringConvertible {
case emptyDocument
case unexpectedEndOfInput(Mark)
case unexpectedCharacter(Character, Mark)
case unterminatedTag(Mark)
case unterminatedComment(Mark)
case unterminatedCDATA(Mark)
case mismatchedEndTag(expected: String, found: String, Mark)
case duplicateAttribute(name: String, Mark)
case expectedName(Mark)
case expectedEquals(Mark)
case unquotedAttributeValue(Mark)
case invalidReference(String, Mark)
case undefinedEntity(name: String, Mark)
case recursiveEntity(name: String, Mark)
case amplificationLimitExceeded(Mark)
case unexpectedEndTag(name: String, Mark)
case undefinedNamespacePrefix(prefix: String, Mark)
case junkAfterDocumentElement(Mark)
case nestingTooDeep(limit: Int, Mark)
case nameTooLong(limit: Int, Mark)
case contentTooLong(limit: Int, Mark)
/// A `<!DOCTYPE ...>` declaration was found. DTD processing is disabled by
/// default as a security posture (XXE, entity-expansion DoS); enabling it
/// is a deliberate future opt-in, not silent behavior.
case unsupportedDoctype(Mark)
/// Raised when raw bytes cannot be decoded in the detected encoding (for
/// example an odd-length UTF-16 stream).
case malformedEncoding
/// Raised by entry points whose parsing path is not implemented yet.
case notImplemented(String)
/// The XML declaration `<?xml ... ?>` is malformed: its pseudo-attributes
/// are out of order, unknown, or carry an illegal value.
case malformedDeclaration(Mark)
/// A comment contains `--`, which XML 1.0 forbids inside comments.
case doubleHyphenInComment(Mark)
/// An attribute value contains a raw `<`, which must be escaped.
case rawLessThanInAttribute(Mark)
/// Character data contains the literal `]]>` sequence, which must be
/// escaped outside a CDATA section.
case cdataCloseInContent(Mark)
/// Two attributes are not separated by whitespace.
case missingSpaceBeforeAttribute(Mark)
/// A character outside the XML `Char` production appears in content.
case invalidCharacter(Mark)
public var description: String {
switch self {
case .emptyDocument:
"document is empty"
case let .unexpectedEndOfInput(mark):
"unexpected end of input at \(mark)"
case let .unexpectedCharacter(character, mark):
"unexpected character '\(character)' at \(mark)"
case let .unterminatedTag(mark):
"unterminated tag starting at \(mark)"
case let .unterminatedComment(mark):
"unterminated comment starting at \(mark)"
case let .unterminatedCDATA(mark):
"unterminated CDATA section starting at \(mark)"
case let .mismatchedEndTag(expected, found, mark):
"expected </\(expected)> but found </\(found)> at \(mark)"
case let .duplicateAttribute(name, mark):
"duplicate attribute '\(name)' at \(mark)"
case let .expectedName(mark):
"expected a name at \(mark)"
case let .expectedEquals(mark):
"expected '=' after attribute name at \(mark)"
case let .unquotedAttributeValue(mark):
"attribute value must be quoted at \(mark)"
case let .invalidReference(reference, mark):
"invalid reference '\(reference)' at \(mark)"
case let .undefinedEntity(name, mark):
"entity '&\(name);' is not declared at \(mark)"
case let .recursiveEntity(name, mark):
"entity '&\(name);' refers to itself at \(mark)"
case let .amplificationLimitExceeded(mark):
"entity expansion exceeds the amplification limit at \(mark)"
case let .unexpectedEndTag(name, mark):
"unexpected end tag </\(name)> at \(mark)"
case let .undefinedNamespacePrefix(prefix, mark):
"namespace prefix '\(prefix)' is not bound at \(mark)"
case let .junkAfterDocumentElement(mark):
"content after the root element at \(mark)"
case let .nestingTooDeep(limit, mark):
"element nesting exceeds the limit of \(limit) at \(mark)"
case let .nameTooLong(limit, mark):
"name exceeds the length limit of \(limit) at \(mark)"
case let .contentTooLong(limit, mark):
"content exceeds the length limit of \(limit) at \(mark)"
case let .unsupportedDoctype(mark):
"DTD processing is disabled (DOCTYPE at \(mark))"
case .malformedEncoding:
"input bytes are malformed for the detected encoding"
case let .notImplemented(detail):
"not implemented: \(detail)"
case let .doubleHyphenInComment(mark):
"'--' is not allowed inside a comment at \(mark)"
case let .rawLessThanInAttribute(mark):
"raw '<' is not allowed in an attribute value at \(mark)"
case let .cdataCloseInContent(mark):
"']]>' must be escaped in character data at \(mark)"
case let .missingSpaceBeforeAttribute(mark):
"attributes must be separated by whitespace at \(mark)"
case let .invalidCharacter(mark):
"character is not allowed in XML content at \(mark)"
case let .malformedDeclaration(mark):
"malformed XML declaration at \(mark)"
}
}
}
}