Mihaela Mihaljevic
204dd3895e
Add PureXML.parse(pullingBytes:) and events(pullingBytes:) over an incremental byte source (() -> UInt8?). StreamingDecoder detects the encoding from the leading bytes, strips any BOM, and yields one scalar at a time as a Character, so a byte stream is never fully buffered. UTF-8 (1 to 4 bytes) and UTF-16 (with surrogate pairs) are decoded incrementally; invalid sequences become the Unicode replacement character. Standard library only, no Foundation. Reimplemented from the documented UTF decoding rules; no upstream code copied.
81 lines
3.1 KiB
Swift
81 lines
3.1 KiB
Swift
@testable import PureXML
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import Testing
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@Suite("Encoding")
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struct EncodingTests {
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@Test("Detects encodings from the leading bytes")
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func test_detect() {
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let detect = PureXML.Parsing.InputEncoding.detect
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#expect(detect([0xEF, 0xBB, 0xBF, 0x3C]) == .utf8)
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#expect(detect([0xFE, 0xFF, 0x00, 0x3C]) == .utf16BigEndian)
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#expect(detect([0xFF, 0xFE, 0x3C, 0x00]) == .utf16LittleEndian)
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#expect(detect([0x00, 0x3C, 0x00, 0x3F]) == .utf16BigEndian)
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#expect(detect([0x3C, 0x00, 0x3F, 0x00]) == .utf16LittleEndian)
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#expect(detect(Array("<r/>".utf8)) == .utf8)
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}
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@Test("Parses UTF-8 bytes, with and without a BOM")
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func test_parseUTF8Bytes() throws {
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let plain = try PureXML.parse(bytes: Array("<r>hi</r>".utf8))
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#expect(rootText(plain) == "hi")
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let withBOM = try PureXML.parse(bytes: [0xEF, 0xBB, 0xBF] + Array("<r>hi</r>".utf8))
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#expect(rootText(withBOM) == "hi")
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}
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@Test("Parses UTF-16 bytes in both byte orders")
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func test_parseUTF16Bytes() throws {
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let bigEndianNode = try PureXML.parse(bytes: utf16("<r>hi</r>", bigEndian: true))
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#expect(rootText(bigEndianNode) == "hi")
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let littleEndianNode = try PureXML.parse(bytes: utf16("<r>hi</r>", bigEndian: false))
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#expect(rootText(littleEndianNode) == "hi")
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}
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@Test("Decodes a UTF-8 byte stream incrementally (multi-byte scalars)")
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func test_streamingUTF8() throws {
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let node = try PureXML.parse(pullingBytes: byteSource(Array("<r>café \u{1F600}</r>".utf8)))
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#expect(rootText(node) == "café \u{1F600}")
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}
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@Test("Decodes a UTF-16 byte stream incrementally, both byte orders")
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func test_streamingUTF16() throws {
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let bigEndianNode = try PureXML.parse(pullingBytes: byteSource(utf16("<r>héllo</r>", bigEndian: true)))
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#expect(rootText(bigEndianNode) == "héllo")
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let littleEndianNode = try PureXML.parse(pullingBytes: byteSource(utf16("<r>héllo</r>", bigEndian: false)))
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#expect(rootText(littleEndianNode) == "héllo")
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}
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@Test("Odd-length UTF-16 input is rejected as malformed")
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func test_malformedUTF16() {
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#expect(throws: PureXML.Parsing.ParseError.malformedEncoding) {
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_ = try PureXML.parse(bytes: [0xFE, 0xFF, 0x00])
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}
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}
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private func byteSource(_ bytes: [UInt8]) -> () -> UInt8? {
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var index = 0
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return {
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guard index < bytes.count else { return nil }
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defer { index += 1 }
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return bytes[index]
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}
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}
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private func utf16(_ string: String, bigEndian: Bool) -> [UInt8] {
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var bytes: [UInt8] = bigEndian ? [0xFE, 0xFF] : [0xFF, 0xFE]
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for unit in string.utf16 {
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let high = UInt8(unit >> 8)
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let low = UInt8(unit & 0xFF)
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bytes += bigEndian ? [high, low] : [low, high]
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}
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return bytes
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}
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private func rootText(_ node: PureXML.Model.Node) -> String? {
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guard case let .document(children) = node else { return nil }
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for child in children {
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if case let .element(element) = child { return element.text }
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}
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return nil
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}
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}
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