autosar_data/

parser.rs

use autosar_data_specification::{
    AttributeName, AttributeSpec, AutosarVersion, CharacterDataSpec, ContentMode, ElementMultiplicity, ElementName,
    ElementType, EnumItem,
};
use smallvec::SmallVec;
use std::borrow::Cow;
use std::collections::HashSet;
use std::path::PathBuf;
use std::str::FromStr;
use std::str::Utf8Error;
use thiserror::Error;

use crate::lexer::{ArxmlEvent, ArxmlLexer};
use crate::{
    Attribute, AutosarDataError, CharacterData, Element, ElementContent, ElementOrModel, ElementRaw, WeakElement,
};

#[derive(Debug, Error)]
#[non_exhaustive]
/// `ArxmlParserError` contains all the errors that can occur while parsing a file
pub enum ArxmlParserError {
    /// The arxml file header is invalid
    #[error("Invalid arxml file: bad file header")]
    InvalidArxmlFileHeader,

    /// An XML file header was unexpectedly found inside the ARXML data
    #[error("Unexpeded XML file header found inside ARXML data")]
    UnexpectedXmlFileHeader {
        /// The element that was open when the unexpected XML file header was found
        element: ElementName,
    },

    /// The file version in the xsi:schemaLocation attribute is unknown
    #[error("Unknown Autosar xsd file {input_verstring} referenced in the file header")]
    UnknownAutosarVersion {
        /// The version string that was found in the file header
        input_verstring: String,
    },

    /// The file version in the xsi:schemaLocation attribute is invalid, but can be corrected
    #[error("Invalid Autosar xsd file {input_verstring} referenced in the file header should be replaced with {}", .replacement.filename())]
    InvalidAutosarVersion {
        /// The version string that was found in the file header
        input_verstring: String,
        /// The corrected version
        replacement: AutosarVersion,
    },

    /// A valid name of an Autosar element was found, but it is not allowed in the current context
    #[error("Encountered unexpected child element {sub_element} inside element {element}")]
    IncorrectBeginElement {
        /// The parent element where the error occurred
        element: ElementName,
        /// The unexpected child element
        sub_element: ElementName,
    },

    /// An xml element was found, but it is not a valid Autosar element
    #[error(
        "Encountered invalid child element {invalid_element} inside parent element {element}. {invalid_element} is not a known Autosar element."
    )]
    InvalidBeginElement {
        /// The parent element where the error occurred
        element: ElementName,
        /// The name of the invalid child element
        invalid_element: String,
    },

    /// An element was opened, but the closing tag for a different element was found
    #[error("Encountered the closing tag for element {other_element}, but element {element} was open.")]
    IncorrectEndElement {
        /// The element that was open when the incorrect closing tag was found
        element: ElementName,
        /// The name of the element that was closed
        other_element: ElementName,
    },

    /// An xml element was closed, but it is not a valid Autosar element
    #[error(
        "Encountered invalid end tag for element {invalid_element} inside parent element {parent_element}. {invalid_element} is not a known Autosar element."
    )]
    InvalidEndElement {
        /// The parent element where the error occurred
        parent_element: ElementName,
        /// The name of the invalid element that was closed
        invalid_element: String,
    },

    /// A parent element contains multiple sub elements which are mutually exclusive
    #[error("Multiple conflicting sub elements have been added to element {element}. The latest was {sub_element}.")]
    ElementChoiceConflict {
        /// The parent element where the error occurred
        element: ElementName,
        /// The name of the conflicting sub element
        sub_element: ElementName,
    },

    /// The element contains a sub element that is not allowed in the current Autosar version
    #[error("Element {sub_element} exists in {element}, but is not allowed in {version}")]
    ElementVersionError {
        /// The parent element where the error occurred
        element: ElementName,
        /// The sub element that is not allowed
        sub_element: ElementName,
        /// The Autosar version in which the sub element is not allowed
        version: AutosarVersion,
    },

    /// A sub element is only allowed to be present once inside a parent element, but another occurrence was found
    #[error("Only one {sub_element} is allowed inside {element}, but another occurrence was found")]
    TooManySubElements {
        /// The parent element where the error occurred
        element: ElementName,
        /// The name of the sub element that was found multiple times
        sub_element: ElementName,
    },

    /// A required sub element is missing from a parent element
    #[error("The required sub element {sub_element} was not found in element {element}")]
    RequiredSubelementMissing {
        /// The parent element where the error occurred
        element: ElementName,
        /// The name of the missing sub element
        sub_element: ElementName,
    },

    /// An attribute value yould not be parsed
    #[error("Could not parse the attribute text \"{attribute_text}\" in element {element}")]
    AttributeValueError {
        /// The element where the error occurred
        element: ElementName,
        /// The attribute text that could not be parsed
        attribute_text: String,
    },

    /// An unknown attribute was found in an element
    #[error("Element {element} contains unknown attribute {attribute}")]
    UnknownAttributeError {
        /// The element where the error occurred
        element: ElementName,
        /// The name of the unknown attribute
        attribute: String,
    },

    /// A known attribute was found, but it is not allowed in the current Autosar version
    #[error("Attribute {attribute} exists in element {element}, but is not allowed in {version}")]
    AttributeVersionError {
        /// The element where the error occurred
        element: ElementName,
        /// The name of the attribute that is not allowed
        attribute: AttributeName,
        /// The Autosar version in which the attribute is not allowed
        version: AutosarVersion,
    },

    /// An attribute is required in an element, but it was not found
    #[error("Attribute {attribute} is required in element {element}, but was not found")]
    RequiredAttributeMissing {
        /// The element where the error occurred
        element: ElementName,
        /// The name of the missing attribute
        attribute: AttributeName,
    },

    /// Character content was found inside an element that does not allow it
    #[error("Character content found, which is not allowed inside element {element}")]
    CharacterContentForbidden {
        /// The element where the error occurred
        element: ElementName,
    },

    /// A valid enum item was found, but it is not allowed in the current autosar version
    #[error("enum item {enum_item} is a valid value in element {element}, but is not allowed in {version}")]
    EnumItemVersionError {
        /// The element where the error occurred
        element: ElementName,
        /// The enum item that is not allowed
        enum_item: EnumItem,
        /// The Autosar version in which the enum item is not allowed
        version: AutosarVersion,
    },

    /// A string could not be parsed as a valid enum item
    #[error("string {value} is not a valid enum item")]
    UnknownEnumItem {
        /// The string that could not be parsed as an enum item
        value: String,
    },

    /// Parsed a valid enum item, but it is not part of the enum in the current context
    #[error("enum item {item} is not valid in element {element}")]
    InvalidEnumItem {
        /// The element where the error occurred
        element: ElementName,
        /// The invalid enum item
        item: EnumItem,
    },

    /// The string value is too long
    #[error("string value {value} is too long: max length is {length}")]
    StringValueTooLong {
        /// The string that is too long
        value: String,
        /// The maximum allowed length
        length: usize,
    },

    /// The string value does not match the validation regex
    #[error("string value {value} is not matched by the validation regex {regex}")]
    RegexMatchError {
        /// The string that does not match the regex
        value: String,
        /// The regex that the string should match
        regex: String,
    },

    /// Some bytes from the input could not be converted to a utf-8 string
    #[error("could not convert value to utf-8: {source}")]
    Utf8Error {
        /// The original error returned by std::str::from_utf8
        source: Utf8Error,
    },

    /// The end of the input was reached unexpectedly while parsing an element
    #[error("Unexpected end of file while parsing element {element}")]
    UnexpectedEndOfFile {
        /// The element that was open when the end of the file was reached
        element: ElementName,
    },

    /// A number was expected, but the input could not be parsed as a number
    #[error("Failed to parse {input} as a number")]
    InvalidNumber {
        /// The input that could not be parsed as a number
        input: String,
    },

    /// The input contains additional data after the final `</AUTOSAR>` element
    #[error("Additional data found in the input after the final </AUTOSAR> element")]
    AdditionalDataError,

    /// The input contains an invalid XML entity
    #[error("Invalid XML entity in {input}")]
    InvalidXmlEntity {
        /// The invalid XML entity
        input: String,
    },
}

pub(crate) struct ArxmlParser<'a> {
    filename: PathBuf,
    line: usize,
    buffer: &'a [u8],
    fileversion: AutosarVersion,
    current_element: ElementName,
    strict: bool,
    version_compatibility: u32,
    pub(crate) identifiables: Vec<(String, WeakElement)>,
    pub(crate) references: Vec<(String, WeakElement)>,
    pub(crate) warnings: Vec<AutosarDataError>,
    standalone: Option<bool>,
}

impl<'a> ArxmlParser<'a> {
    pub(crate) fn new(filename: PathBuf, buffer: &'a [u8], strict: bool) -> Self {
        Self {
            filename,
            line: 1,
            buffer,
            fileversion: AutosarVersion::Autosar_4_0_1, // this is temporary and gets replaced as soon as the xsd declaration in the top-level AUTOSAR element is read
            current_element: ElementName::Autosar,
            strict,
            version_compatibility: u32::MAX,
            identifiables: Vec::new(),
            references: Vec::new(),
            warnings: Vec::new(),
            standalone: None,
        }
    }

    fn next<'b>(&mut self, lexer: &'b mut ArxmlLexer) -> Result<ArxmlEvent<'b>, AutosarDataError> {
        let (line, event) = lexer.next()?;
        self.line = line;
        Ok(event)
    }

    pub(crate) fn error(&self, err: ArxmlParserError) -> AutosarDataError {
        AutosarDataError::ParserError {
            filename: self.filename.clone(),
            line: self.line,
            source: err,
        }
    }

    pub(crate) fn optional_error(&mut self, err: ArxmlParserError) -> Result<(), AutosarDataError> {
        let wrapped_err = AutosarDataError::ParserError {
            filename: self.filename.clone(),
            line: self.line,
            source: err,
        };
        if self.strict {
            Err(wrapped_err)
        } else {
            self.warnings.push(wrapped_err);
            Ok(())
        }
    }

    fn check_version(&mut self, item_version: u32, error: ArxmlParserError) -> Result<(), AutosarDataError> {
        self.version_compatibility &= item_version;
        if (self.fileversion as u32) & item_version == 0 {
            self.optional_error(error)
        } else {
            Ok(())
        }
    }

    /// parse an arxml file and return the root element of the parsed hierarchy
    pub(crate) fn parse_arxml(&mut self) -> Result<Element, AutosarDataError> {
        let mut lexer = ArxmlLexer::new(self.buffer, self.filename.clone());

        if let ArxmlEvent::ArxmlHeader(standalone) = self.next(&mut lexer)? {
            self.standalone = standalone;
        } else {
            return Err(self.error(ArxmlParserError::InvalidArxmlFileHeader));
        }

        let mut stored_comment = None;
        let mut token = self.next(&mut lexer)?;
        while let ArxmlEvent::Comment(comment_bytes) = token {
            stored_comment = Some(String::from_utf8_lossy(comment_bytes).into());
            token = self.next(&mut lexer)?;
        }

        if let ArxmlEvent::BeginElement(elemname, attributes_text) = token
            && let Ok(ElementName::Autosar) = ElementName::from_bytes(elemname)
        {
            let attributes = self.parse_attribute_text(ElementType::ROOT, attributes_text)?;
            self.parse_file_header(&attributes)?;

            let new_element = ElementRaw {
                parent: ElementOrModel::None,
                elemname: ElementName::Autosar,
                elemtype: ElementType::ROOT,
                content: SmallVec::new(),
                attributes,
                file_membership: HashSet::with_capacity(0),
                comment: stored_comment,
            };
            let path = Cow::from("");
            let autosar_root_element = self.parse_element(new_element, path, &mut lexer)?;
            self.verify_end_of_input(&mut lexer)?;

            return Ok(autosar_root_element);
        }
        Err(self.error(ArxmlParserError::InvalidArxmlFileHeader))
    }

    /// parse the arxml file header
    fn parse_file_header(&mut self, attributes: &SmallVec<[Attribute; 1]>) -> Result<(), AutosarDataError> {
        let attr_xmlns = attributes.iter().find(|attr| attr.attrname == AttributeName::xmlns);
        let attr_xsi = attributes.iter().find(|attr| attr.attrname == AttributeName::xmlnsXsi);
        let attr_schema = attributes
            .iter()
            .find(|attr| attr.attrname == AttributeName::xsiSchemalocation);
        if let (
            Some(Attribute {
                content: CharacterData::String(xmlns),
                ..
            }),
            Some(Attribute {
                content: CharacterData::String(xsi),
                ..
            }),
            Some(Attribute {
                content: CharacterData::String(schema),
                ..
            }),
        ) = (attr_xmlns, attr_xsi, attr_schema)
        {
            if xmlns != "http://autosar.org/schema/r4.0" || xsi != "http://www.w3.org/2001/XMLSchema-instance" {
                return Err(self.error(ArxmlParserError::InvalidArxmlFileHeader));
            }
            self.fileversion = self.parse_file_version(schema)?;

            Ok(())
        } else {
            Err(self.error(ArxmlParserError::InvalidArxmlFileHeader))
        }
    }

    /// get the file version from the value of the xsi:schemaLocation attribute
    fn parse_file_version(&mut self, schema: &str) -> Result<AutosarVersion, AutosarDataError> {
        let mut schema_parts = schema.split(' ');
        let schema_base = schema_parts.next().unwrap_or("");
        if schema_base != "http://autosar.org/schema/r4.0" {
            return Err(self.error(ArxmlParserError::InvalidArxmlFileHeader));
        }
        let xsd_file_raw = schema_parts.next().unwrap_or("");
        let xsd_file: String = if xsd_file_raw.starts_with("autosar") {
            format!("AUTOSAR{}", xsd_file_raw.strip_prefix("autosar").unwrap())
        } else {
            xsd_file_raw.to_owned()
        };
        let version = if let Ok(autosar_version) = AutosarVersion::from_str(&xsd_file) {
            autosar_version
        } else if xsd_file == "AUTOSAR_4-3-1.xsd" {
            // compat helper - a manually edited file might have a plausible but invalid version which can be corrected
            // AUTOSAR_4-3-1.xsd -> AUTOSAR_00044.xsd
            self.optional_error(ArxmlParserError::InvalidAutosarVersion {
                input_verstring: xsd_file.to_string(),
                replacement: AutosarVersion::Autosar_00044,
            })?;
            AutosarVersion::Autosar_00044
        } else if xsd_file == "AUTOSAR_4-4-0.xsd" {
            // compat helper - a manually edited file might have a plausible but invalid version which can be corrected
            // AUTOSAR_4-4-0.xsd -> AUTOSAR_00046.xsd
            self.optional_error(ArxmlParserError::InvalidAutosarVersion {
                input_verstring: xsd_file.to_string(),
                replacement: AutosarVersion::Autosar_00046,
            })?;
            AutosarVersion::Autosar_00046
        } else if xsd_file == "AUTOSAR_4-5-0.xsd" {
            // compat helper - a manually edited file might have a plausible but invalid version which can be corrected
            // AUTOSAR_4-5-0.xsd -> AUTOSAR_00048.xsd
            self.optional_error(ArxmlParserError::InvalidAutosarVersion {
                input_verstring: xsd_file.to_string(),
                replacement: AutosarVersion::Autosar_00048,
            })?;
            AutosarVersion::Autosar_00048
        } else {
            self.optional_error(ArxmlParserError::UnknownAutosarVersion {
                input_verstring: xsd_file.to_string(),
            })?;
            AutosarVersion::LATEST
        };
        Ok(version)
    }

    /// return the standalone attribute from the xml header
    pub(crate) fn get_standalone(&self) -> Option<bool> {
        self.standalone
    }

    /// parse a single element of an arxml file
    fn parse_element(
        &mut self,
        raw_element: ElementRaw,
        mut path: Cow<str>,
        lexer: &mut ArxmlLexer,
    ) -> Result<Element, AutosarDataError> {
        let wrapped_element = raw_element.wrap();
        let mut element = wrapped_element.0.write();

        let mut elem_idx: Vec<usize> = Vec::new();
        let mut short_name_found = false;

        let mut stored_comment = None;
        loop {
            // track the current element name in the parser for error messages - set this in every loop iteration, since it gets overwritten during the recursive calls
            self.current_element = element.elemname;
            let arxmlevent = self.next(lexer)?;
            match arxmlevent {
                ArxmlEvent::BeginElement(elem_text, attr_text) => {
                    if let Ok(name) = ElementName::from_bytes(elem_text) {
                        let (sub_elemtype, idx) = self.find_element_in_spec_checked(name, element.elemtype)?;
                        self.check_element_conflict(name, element.elemtype, &elem_idx, &idx)?;
                        elem_idx = idx;

                        // make sure there aren't too many of this kind of element
                        if !element.content.is_empty() {
                            self.check_multiplicity(name, element.elemtype, &elem_idx, &element)?;
                        }

                        // recursively parse the sub element and its sub sub elements
                        let new_element = ElementRaw {
                            parent: ElementOrModel::Element(wrapped_element.downgrade()),
                            elemname: name,
                            elemtype: sub_elemtype,
                            content: SmallVec::new(),
                            attributes: self.parse_attribute_text(sub_elemtype, attr_text)?,
                            file_membership: HashSet::with_capacity(0),
                            comment: stored_comment,
                        };
                        let sub_element = self.parse_element(new_element, Cow::from(path.as_ref()), lexer)?;
                        stored_comment = None;
                        // if this sub element was a short name, then Autosar path handling is needed
                        if name == ElementName::ShortName {
                            short_name_found = true;
                            let sub_element_inner = sub_element.0.read();
                            if let Some(ElementContent::CharacterData(CharacterData::String(name_string))) =
                                sub_element_inner.content.first()
                            {
                                let mut new_path = String::with_capacity(path.len() + name_string.len() + 1);
                                new_path.push_str(&path);
                                new_path.push('/');
                                new_path.push_str(name_string);
                                path = Cow::from(new_path.clone());
                                self.identifiables.push((new_path, wrapped_element.downgrade()));
                            }
                        }
                        element.content.push(ElementContent::Element(sub_element));
                    } else {
                        return Err(self.error(ArxmlParserError::InvalidBeginElement {
                            element: element.elemname,
                            invalid_element: String::from_utf8_lossy(elem_text).to_string(),
                        }));
                    }
                }
                ArxmlEvent::EndElement(elem_text) => {
                    if let Ok(name) = ElementName::from_bytes(elem_text) {
                        if name == element.elemname {
                            break;
                        }
                        return Err(self.error(ArxmlParserError::IncorrectEndElement {
                            element: element.elemname,
                            other_element: name,
                        }));
                    }
                    return Err(self.error(ArxmlParserError::InvalidEndElement {
                        parent_element: element.elemname,
                        invalid_element: String::from_utf8_lossy(elem_text).to_string(),
                    }));
                }
                ArxmlEvent::Characters(text_content) => {
                    if let Some(character_data_spec) = element.elemtype.chardata_spec() {
                        let value = self.parse_character_data(text_content, character_data_spec)?;
                        if element.elemtype.is_ref()
                            && let CharacterData::String(refpath) = &value
                        {
                            self.references.push((refpath.to_owned(), wrapped_element.downgrade()));
                        }
                        element.content.push(ElementContent::CharacterData(value));
                    } else {
                        self.optional_error(ArxmlParserError::CharacterContentForbidden {
                            element: element.elemname,
                        })?;
                    }
                }
                ArxmlEvent::ArxmlHeader(_) => self.optional_error(ArxmlParserError::UnexpectedXmlFileHeader {
                    element: element.elemname,
                })?,
                ArxmlEvent::EndOfFile => {
                    return Err(self.error(ArxmlParserError::UnexpectedEndOfFile {
                        element: element.elemname,
                    }));
                }
                ArxmlEvent::Comment(comment_bytes) => {
                    stored_comment = Some(String::from_utf8_lossy(comment_bytes).into());
                }
            }
        }

        if short_name_found {
        } else if element.elemtype.is_named_in_version(self.fileversion) {
            self.optional_error(ArxmlParserError::RequiredSubelementMissing {
                element: element.elemname,
                sub_element: ElementName::ShortName,
            })?;
        }

        Ok(wrapped_element.clone())
    }

    fn find_element_in_spec_checked(
        &mut self,
        name: ElementName,
        elemtype: ElementType,
    ) -> Result<(ElementType, Vec<usize>), AutosarDataError> {
        // Some elements have multiple entries, and the correct one must be chosen based on the autosar version
        // First try to find the sub element using the current file version. If that fails then search again
        // allowing elements from all autosar versions. This is useful in order to give better diagnostics.
        let (sub_elem_type, new_elem_indices) =
            if let Some(result) = elemtype.find_sub_element(name, self.fileversion as u32) {
                // normal case: the element was found in the spec, while restricted to only the current version
                result
            } else {
                // fallback: the search is retried, while allowing matching sub-elements from any AutosarVersion
                let (sub_elemtype, elem_idx) = elemtype.find_sub_element(name, u32::MAX).ok_or_else(|| {
                    self.error(ArxmlParserError::IncorrectBeginElement {
                        element: self.current_element,
                        sub_element: name,
                    })
                })?;
                // now we need to get the version mask that tells us in what versions this element was actually allowed in
                // unwrap() is ok here since this can't fail: elem_idx just came from find_sub_element
                let version_mask = elemtype.get_sub_element_version_mask(&elem_idx).unwrap();
                // check_version will return an ElementVersionError is strict parsing is on, otherwise it's a warning
                self.check_version(
                    version_mask,
                    ArxmlParserError::ElementVersionError {
                        element: self.current_element,
                        sub_element: name,
                        version: self.fileversion,
                    },
                )?;
                (sub_elemtype, elem_idx)
            };

        Ok((sub_elem_type, new_elem_indices))
    }

    fn check_element_conflict(
        &mut self,
        name: ElementName,
        elemtype: ElementType,
        elem_indices: &[usize],
        new_elem_indices: &Vec<usize>,
    ) -> Result<(), AutosarDataError> {
        if elem_indices.is_empty() || (elem_indices == new_elem_indices) {
            // when elem_indices is empty, that means that this is the first sub-element or found the exact same element as last time
            // no ordering checks are possible
        } else {
            let group_type = elemtype.find_common_group(elem_indices, new_elem_indices);
            let mode = group_type.content_mode();

            match mode {
                ContentMode::Sequence => {
                    // We could check if the elements are in the specified order.
                    // Unfortunaltely the tool used by the Autosar organisation to derive the xsd files from the meta model seems to be buggy.
                    // For example, VARIATION-POINT should always be last according to the meta model, but some of the xsd files do not place it there.
                    // Since other tools seem to skip this check, lets also ignore ordering.
                }
                ContentMode::Choice => {
                    self.optional_error(ArxmlParserError::ElementChoiceConflict {
                        element: self.current_element,
                        sub_element: name,
                    })?;
                }
                ContentMode::Characters => {
                    // an element with ContentMode::Characters has no sub elements, so the outer "if let Some(new_elem_indices)" is never true
                    panic!("accepted a sub-element inside a character-only element");
                }
                _ => {}
            }
        }
        Ok(())
    }

    fn check_multiplicity(
        &mut self,
        name: ElementName,
        elemtype: ElementType,
        elem_idx: &[usize],
        element: &ElementRaw,
    ) -> Result<(), AutosarDataError> {
        // get the parent type id, i.e. the type of the containing element or group
        let datatype_mode = elemtype.get_sub_element_container_mode(elem_idx);
        // multiplicity only matters if the mode is Choice or Sequence - modes Mixed and Bag allow arbitrary amounts of all elements
        if (datatype_mode == ContentMode::Sequence || datatype_mode == ContentMode::Choice)
            && let Some(multiplicity) = elemtype.get_sub_element_multiplicity(elem_idx)
        {
            // multiplicity only needs to be checked if it is not Any - i.e. One / ZeroOrOne
            if multiplicity != ElementMultiplicity::Any {
                // there is a conflict if there is already a subelement with the same ElementName
                if element.content.iter().any(|ec| {
                    ec.unwrap_element()
                        .is_some_and(|subelem| subelem.element_name() == name)
                }) {
                    self.optional_error(ArxmlParserError::TooManySubElements {
                        element: self.current_element,
                        sub_element: name,
                    })?;
                }
            }
        }
        Ok(())
    }

    fn parse_attribute_text(
        &mut self,
        elemtype: ElementType,
        attributes_text: &[u8],
    ) -> Result<SmallVec<[Attribute; 1]>, AutosarDataError> {
        let mut attributes = SmallVec::new();
        // attributes_text is a byte string containig all the attributes of an element
        // for example: xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_4-2-2.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        let startpos = attributes_text
            .iter()
            .position(|c| !c.is_ascii_whitespace())
            .unwrap_or(0);
        let mut rem = &attributes_text[startpos..];
        while let Some(equals_pos) = rem.iter().position(|c| *c == b'=') {
            let attr_name_part = &rem[..equals_pos];
            if rem.len() - equals_pos < 3 {
                // minimally the attribute name should be followed by an equals sign and two quotes (empty string)
                break;
            }
            let quote_char = rem[equals_pos + 1];
            if quote_char != b'"' && quote_char != b'\'' {
                // the attribute value should be enclosed in quotes
                break;
            }
            rem = &rem[equals_pos + 2..];
            let Some(endquote_pos) = rem.iter().position(|c| c == &quote_char) else {
                // failed to find the end of the attribute value
                break;
            };
            let attr_value_part = &rem[..endquote_pos];

            if let Ok(attr_name) = AttributeName::from_bytes(attr_name_part) {
                if let Some(AttributeSpec {
                    spec: ctype,
                    version: version_mask,
                    ..
                }) = elemtype.find_attribute_spec(attr_name)
                {
                    self.check_version(
                        version_mask,
                        ArxmlParserError::AttributeVersionError {
                            element: self.current_element,
                            attribute: attr_name,
                            version: self.fileversion,
                        },
                    )?;
                    let attr_value = self.parse_character_data(attr_value_part, ctype)?;
                    attributes.push(Attribute {
                        attrname: attr_name,
                        content: attr_value,
                    });
                } else {
                    self.optional_error(ArxmlParserError::UnknownAttributeError {
                        element: self.current_element,
                        attribute: attr_name.to_string(),
                    })?;
                }
            } else {
                self.optional_error(ArxmlParserError::UnknownAttributeError {
                    element: self.current_element,
                    attribute: String::from_utf8_lossy(attr_name_part).to_string(),
                })?;
            }

            // skip whitespace and move to the next attribute
            let mut nextattr_start = endquote_pos + 1;
            while nextattr_start < rem.len() && rem[nextattr_start].is_ascii_whitespace() {
                nextattr_start += 1;
            }

            // verify that there was at least one whitespace character after the end quote
            if nextattr_start < rem.len() && nextattr_start == endquote_pos + 1 {
                // the attributes should be separated by whitespace; if not then there is a problem in the file
                break;
            }
            rem = &rem[nextattr_start..];
        }

        if !rem.is_empty() && !rem.iter().all(|c| c.is_ascii_whitespace()) {
            self.optional_error(ArxmlParserError::AttributeValueError {
                element: self.current_element,
                attribute_text: String::from_utf8_lossy(attributes_text).into_owned(),
            })?;
        }

        for (name, _ctype, required) in elemtype.attribute_spec_iter() {
            if required && !attributes.iter().any(|attr: &Attribute| attr.attrname == name) {
                self.optional_error(ArxmlParserError::RequiredAttributeMissing {
                    element: self.current_element,
                    attribute: name,
                })?;
            }
        }

        Ok(attributes)
    }

    fn parse_character_data(
        &mut self,
        input: &[u8],
        character_data_spec: &CharacterDataSpec,
    ) -> Result<CharacterData, AutosarDataError> {
        let trimmed_input = trim_byte_string(input);
        match character_data_spec {
            CharacterDataSpec::Enum { items } => {
                let value = EnumItem::from_bytes(trimmed_input).map_err(|_| {
                    self.error(ArxmlParserError::UnknownEnumItem {
                        value: String::from_utf8_lossy(trimmed_input).to_string(),
                    })
                })?;
                let (_, version) = items.iter().find(|(item, _)| *item == value).ok_or_else(|| {
                    self.error(ArxmlParserError::InvalidEnumItem {
                        element: self.current_element,
                        item: value,
                    })
                })?;
                self.check_version(
                    *version,
                    ArxmlParserError::EnumItemVersionError {
                        element: self.current_element,
                        enum_item: value,
                        version: self.fileversion,
                    },
                )?;
                Ok(CharacterData::Enum(value))
            }
            CharacterDataSpec::Pattern {
                check_fn,
                regex,
                max_length,
            } => {
                if max_length.is_some() && trimmed_input.len() > max_length.unwrap() {
                    self.optional_error(ArxmlParserError::StringValueTooLong {
                        value: String::from_utf8_lossy(trimmed_input).to_string(),
                        length: max_length.unwrap(),
                    })?;
                }
                if !check_fn(trimmed_input) {
                    self.optional_error(ArxmlParserError::RegexMatchError {
                        value: String::from_utf8_lossy(trimmed_input).to_string(),
                        regex: (*regex).to_string(),
                    })?;
                }
                // text with regex pattern validation doesn't need unescaping - none of the regexes will allow any of the the escaped chars
                match std::str::from_utf8(trimmed_input) {
                    Ok(utf8string) => Ok(CharacterData::String(utf8string.to_owned())),
                    Err(err) => {
                        self.optional_error(ArxmlParserError::Utf8Error { source: err })?;
                        Ok(CharacterData::String(
                            String::from_utf8_lossy(trimmed_input).into_owned(),
                        ))
                    }
                }
            }
            CharacterDataSpec::String {
                preserve_whitespace,
                max_length,
            } => {
                let raw_text = if *preserve_whitespace { input } else { trimmed_input };
                if max_length.is_some() && raw_text.len() > max_length.unwrap() {
                    self.optional_error(ArxmlParserError::StringValueTooLong {
                        value: String::from_utf8_lossy(trimmed_input).to_string(),
                        length: max_length.unwrap(),
                    })?;
                }
                let text = match std::str::from_utf8(raw_text) {
                    Ok(utf8string) => Cow::from(utf8string),
                    Err(err) => {
                        self.optional_error(ArxmlParserError::Utf8Error { source: err })?;
                        String::from_utf8_lossy(raw_text)
                    }
                };
                let unescaped_text = self.unescape_string(&text)?.into_owned();
                Ok(CharacterData::String(unescaped_text))
            }
            CharacterDataSpec::UnsignedInteger => {
                let strval = std::str::from_utf8(trimmed_input)
                    .map_err(|err| self.error(ArxmlParserError::Utf8Error { source: err }))?;
                let value = match strval.parse::<u64>() {
                    Ok(parsed) => parsed,
                    Err(_) => {
                        self.optional_error(ArxmlParserError::InvalidNumber {
                            input: strval.to_owned(),
                        })?;
                        0
                    }
                };
                Ok(CharacterData::UnsignedInteger(value))
            }
            CharacterDataSpec::Float => {
                let strval = std::str::from_utf8(trimmed_input)
                    .map_err(|err| self.error(ArxmlParserError::Utf8Error { source: err }))?;
                let value = match strval.parse::<f64>() {
                    Ok(parsed) => parsed,
                    Err(_) => {
                        self.optional_error(ArxmlParserError::InvalidNumber {
                            input: strval.to_owned(),
                        })?;
                        0.0
                    }
                };
                Ok(CharacterData::Float(value))
            }
        }
    }

    fn unescape_string<'b>(&mut self, input: &'b str) -> Result<Cow<'b, str>, AutosarDataError> {
        if input.contains('&') {
            let mut unescaped = String::with_capacity(input.len());
            let mut rem = input;
            while let Some(pos) = rem.find('&') {
                unescaped.push_str(&rem[..pos]);
                rem = &rem[pos..];
                if rem.starts_with("&lt;") {
                    unescaped.push('<');
                    rem = &rem[4..];
                } else if rem.starts_with("&gt;") {
                    unescaped.push('>');
                    rem = &rem[4..];
                } else if rem.starts_with("&amp;") {
                    unescaped.push('&');
                    rem = &rem[5..];
                } else if rem.starts_with("&apos;") {
                    unescaped.push('\'');
                    rem = &rem[6..];
                } else if rem.starts_with("&quot;") {
                    unescaped.push('"');
                    rem = &rem[6..];
                } else if rem.starts_with("&#x") {
                    // hexadecimal character reference
                    let mut valid = false;
                    if let Some(endpos) = rem.find(';') {
                        let hextxt = &rem[3..endpos];
                        if let Ok(hexval) = u32::from_str_radix(hextxt, 16)
                            && let Some(ch) = char::from_u32(hexval)
                        {
                            unescaped.push(ch);
                            rem = &rem[endpos + 1..];
                            valid = true;
                        }
                    }
                    if !valid {
                        self.optional_error(ArxmlParserError::InvalidXmlEntity {
                            input: input.to_owned(),
                        })?;
                        unescaped.push('&');
                        rem = &rem[1..];
                    }
                } else if rem.starts_with("&#") {
                    // decimal character reference
                    let mut valid = false;
                    if let Some(endpos) = rem.find(';') {
                        let numtxt = &rem[2..endpos];
                        if let Ok(val) = u32::from_str(numtxt)
                            && let Some(ch) = char::from_u32(val)
                        {
                            unescaped.push(ch);
                            rem = &rem[endpos + 1..];
                            valid = true;
                        }
                    }
                    if !valid {
                        self.optional_error(ArxmlParserError::InvalidXmlEntity {
                            input: input.to_owned(),
                        })?;
                        unescaped.push('&');
                        rem = &rem[1..];
                    }
                } else {
                    self.optional_error(ArxmlParserError::InvalidXmlEntity {
                        input: input.to_owned(),
                    })?;
                    unescaped.push('&');
                    rem = &rem[1..];
                }
            }
            unescaped.push_str(rem);

            Ok(Cow::Owned(unescaped))
        } else {
            Ok(Cow::Borrowed(input))
        }
    }

    pub(crate) fn get_fileversion(&self) -> AutosarVersion {
        self.fileversion
    }

    fn verify_end_of_input(&mut self, lexer: &mut ArxmlLexer) -> Result<(), AutosarDataError> {
        let (_, next_event) = lexer.next()?;
        if let ArxmlEvent::EndOfFile = next_event {
            Ok(())
        } else {
            self.optional_error(ArxmlParserError::AdditionalDataError)?;
            Ok(())
        }
    }

    /// parse an arxml file and return the root element of the parsed hierarchy
    pub(crate) fn check_arxml_header(&mut self) -> bool {
        let mut lexer = ArxmlLexer::new(self.buffer, self.filename.clone());

        if let Ok(ArxmlEvent::ArxmlHeader(_)) = self.next(&mut lexer) {
            // skip any comments
            let mut arxmlevent = self.next(&mut lexer);
            while let Ok(ArxmlEvent::Comment(..)) = arxmlevent {
                arxmlevent = self.next(&mut lexer);
            }
            if let Ok(ArxmlEvent::BeginElement(elemname, attributes_text)) = arxmlevent
                && let Ok(ElementName::Autosar) = ElementName::from_bytes(elemname)
                && let Ok(attributes) = self.parse_attribute_text(ElementType::ROOT, attributes_text)
                && self.parse_file_header(&attributes).is_ok()
            {
                // no errors after parsing the header - this looks like an arxml file
                return true;
            }
        }

        false
    }
}

fn trim_byte_string(input: &[u8]) -> &[u8] {
    let mut len = input.len();
    if len > 0 {
        while input[len - 1].is_ascii_whitespace() {
            len -= 1;
        }
        let start = input.iter().position(|c| !c.is_ascii_whitespace()).unwrap_or(len);
        &input[start..len]
    } else {
        input
    }
}

#[cfg(test)]
mod test {
    use crate::parser::*;
    use crate::*;

    fn test_helper(buffer: &[u8], target_error: std::mem::Discriminant<ArxmlParserError>, optional: bool) {
        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), buffer, true);
        let result = parser.parse_arxml();
        if let Err(AutosarDataError::ParserError { source, .. }) = result {
            println!("Error result: {source:?}");
            assert_eq!(
                std::mem::discriminant(&source),
                target_error,
                "Did not get the expected parser error"
            );
        } else {
            panic!("Did not get any parser error when one was expected");
        }

        if optional {
            let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), buffer, false);
            let _result = parser.parse_arxml();
            if let Some(AutosarDataError::ParserError { source, .. }) = parser.warnings.first() {
                println!("Warnings result: {source:?}");
                assert_eq!(
                    std::mem::discriminant(source),
                    target_error,
                    "Did not get the expected parser error"
                );
            } else {
                panic!("Did not get a parser warning");
            }
        }
    }

    const INVALID_HEADER_1: &str = "BLA BLA bla";
    const INVALID_HEADER_2: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <something>"#;
    const INVALID_HEADER_3: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="nonsense" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">"#;
    const INVALID_HEADER_4: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00049.xsd" xmlns="http://other" xmlns:xsi="http://other">"#;

    #[test]
    fn test_invalid_header() {
        test_helper(
            INVALID_HEADER_1.as_bytes(),
            std::mem::discriminant(&ArxmlParserError::InvalidArxmlFileHeader),
            false,
        );
        test_helper(
            INVALID_HEADER_2.as_bytes(),
            std::mem::discriminant(&ArxmlParserError::InvalidArxmlFileHeader),
            false,
        );
        test_helper(
            INVALID_HEADER_3.as_bytes(),
            std::mem::discriminant(&ArxmlParserError::InvalidArxmlFileHeader),
            false,
        );
        test_helper(
            INVALID_HEADER_4.as_bytes(),
            std::mem::discriminant(&ArxmlParserError::InvalidArxmlFileHeader),
            false,
        );
    }

    const HDR_SINGLE_QUOTE: &str = r#"<?xml version='1.0' encoding='utf-8'?>
    <AUTOSAR xsi:schemaLocation='http://autosar.org/schema/r4.0 autosar_4-3-0.xsd' xmlns='http://autosar.org/schema/r4.0' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'>
    </AUTOSAR>"#;

    #[test]
    fn single_quotes_in_header() {
        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), HDR_SINGLE_QUOTE.as_bytes(), true);
        let result = parser.parse_arxml();
        assert!(result.is_ok());
    }

    const SCHEMA_VERSION_LC: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 autosar_4-3-0.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    </AUTOSAR>"#;
    const INVALID_VERSION_4_3_1: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_4-3-1.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    </AUTOSAR>"#;
    const INVALID_VERSION_4_4_0: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_4-4-0.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    </AUTOSAR>"#;
    const INVALID_VERSION_4_5_0: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_4-5-0.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    </AUTOSAR>"#;

    #[test]
    fn test_invalid_version() {
        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), SCHEMA_VERSION_LC.as_bytes(), true);
        let result = parser.parse_arxml();
        assert!(result.is_ok());

        let discriminant = std::mem::discriminant(&ArxmlParserError::InvalidAutosarVersion {
            input_verstring: "".to_string(),
            replacement: AutosarVersion::Autosar_00044,
        });
        test_helper(INVALID_VERSION_4_3_1.as_bytes(), discriminant, true);
        test_helper(INVALID_VERSION_4_4_0.as_bytes(), discriminant, true);
        test_helper(INVALID_VERSION_4_5_0.as_bytes(), discriminant, true);
    }

    const UNKNOWN_VERSION: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_something_else.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    </AUTOSAR>"#;

    #[test]
    fn test_unknown_version() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::UnknownAutosarVersion {
            input_verstring: "".to_string(),
        });
        test_helper(UNKNOWN_VERSION.as_bytes(), discriminant, true);
    }

    const UNEXPECTED_XML_FILE_HEADER: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <?xml version="1.0" encoding="utf-8"?>
    </AUTOSAR>"#;

    #[test]
    fn test_unexpected_xml_file_header() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::UnexpectedXmlFileHeader {
            element: ElementName::Autosar,
        });
        test_helper(UNEXPECTED_XML_FILE_HEADER.as_bytes(), discriminant, true);
    }

    const INCORRECT_BEGIN_ELEMENT: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <ELEMENT>"#;

    #[test]
    fn test_incorrect_begin_element() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::IncorrectBeginElement {
            element: ElementName::Autosar,
            sub_element: ElementName::Autosar,
        });
        test_helper(INCORRECT_BEGIN_ELEMENT.as_bytes(), discriminant, false);
    }

    const INVALID_BEGIN_ELEMENT: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <NOT_AN_AUTOSAR_ELEMENT>"#;

    #[test]
    fn test_invalid_begin_element() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::InvalidBeginElement {
            element: ElementName::Autosar,
            invalid_element: "".to_string(),
        });
        test_helper(INVALID_BEGIN_ELEMENT.as_bytes(), discriminant, false);
    }

    const INCORRECT_END_ELEMENT: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <AR-PACKAGES></AUTOSAR>"#;

    #[test]
    fn test_incorrect_end_element() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::IncorrectEndElement {
            element: ElementName::Autosar,
            other_element: ElementName::Autosar,
        });
        test_helper(INCORRECT_END_ELEMENT.as_bytes(), discriminant, false);
    }

    const INVALID_END_ELEMENT: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <AR-PACKAGES></NOT_AN_AUTOSAR_ELEMENT>"#;

    #[test]
    fn test_invalid_end_element() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::InvalidEndElement {
            parent_element: ElementName::Autosar,
            invalid_element: "".to_string(),
        });
        test_helper(INVALID_END_ELEMENT.as_bytes(), discriminant, false);
    }

    const ELEMENT_VERSION_ERROR: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_4-0-1.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <AR-PACKAGES><AR-PACKAGE><SHORT-NAME>TestPackage</SHORT-NAME><ELEMENTS><DIAGNOSTIC-ACCESS-PERMISSION>"#;

    #[test]
    fn test_element_version_error() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::ElementVersionError {
            element: ElementName::Autosar,
            sub_element: ElementName::Autosar,
            version: AutosarVersion::Autosar_00050,
        });
        test_helper(ELEMENT_VERSION_ERROR.as_bytes(), discriminant, false);
    }

    const CHOICE_CONFLICT: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES>
            <AR-PACKAGE>
                <SHORT-NAME>base</SHORT-NAME>
                <ELEMENTS>
                    <DIAGNOSTIC-CONTRIBUTION-SET>
                        <SHORT-NAME>dcs</SHORT-NAME>
                        <COMMON-PROPERTIES>
                            <DIAGNOSTIC-COMMON-PROPS-VARIANTS>
                                <DIAGNOSTIC-COMMON-PROPS-CONDITIONAL>
                                    <DEBOUNCE-ALGORITHM-PROPSS>
                                        <DIAGNOSTIC-DEBOUNCE-ALGORITHM-PROPS>
                                            <SHORT-NAME>props</SHORT-NAME>
                                            <DEBOUNCE-ALGORITHM>
                                                <DIAG-EVENT-DEBOUNCE-COUNTER-BASED>
                                                    <SHORT-NAME>abc</SHORT-NAME>
                                                </DIAG-EVENT-DEBOUNCE-COUNTER-BASED>
                                                <DIAG-EVENT-DEBOUNCE-TIME-BASED>
                                                    <SHORT-NAME>def</SHORT-NAME>
                                                </DIAG-EVENT-DEBOUNCE-TIME-BASED>"#;

    #[test]
    fn test_choice_conflict() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::ElementChoiceConflict {
            element: ElementName::Autosar,
            sub_element: ElementName::Autosar,
        });
        test_helper(CHOICE_CONFLICT.as_bytes(), discriminant, true);
    }

    const TOO_MANY_SUBELEMENTS: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES>
            <AR-PACKAGE>
                <SHORT-NAME>base</SHORT-NAME>
                <SHORT-NAME>base</SHORT-NAME>"#;

    #[test]
    fn test_too_many_sub_elements() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::TooManySubElements {
            element: ElementName::Autosar,
            sub_element: ElementName::Autosar,
        });
        test_helper(TOO_MANY_SUBELEMENTS.as_bytes(), discriminant, true);
    }

    const REQUIRED_SUB_ELEMENT_MISSING: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES>
            <AR-PACKAGE></AR-PACKAGE>"#;

    #[test]
    fn test_required_sub_element_missing() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::RequiredSubelementMissing {
            element: ElementName::Autosar,
            sub_element: ElementName::Autosar,
        });
        test_helper(REQUIRED_SUB_ELEMENT_MISSING.as_bytes(), discriminant, false);
    }

    const UNKNOWN_ATTRIBUTE: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <AR-PACKAGES UnknownAttribute="value">
    </AR-PACKAGES></AUTOSAR>"#;
    const UNKNOWN_ATTRIBUTE_2: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <AR-PACKAGES DEST="value">
    </AR-PACKAGES></AUTOSAR>"#;

    #[test]
    fn test_unknown_attribute() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::UnknownAttributeError {
            element: ElementName::Autosar,
            attribute: "".to_string(),
        });
        test_helper(UNKNOWN_ATTRIBUTE.as_bytes(), discriminant, true);
        let discriminant = std::mem::discriminant(&ArxmlParserError::UnknownAttributeError {
            element: ElementName::Autosar,
            attribute: "DEST".to_string(),
        });
        test_helper(UNKNOWN_ATTRIBUTE_2.as_bytes(), discriminant, true);
    }

    const REQUIRED_ATTRIBUTE_MISSING: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0">
    </AUTOSAR>"#;

    #[test]
    fn test_required_attribute_missing() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::RequiredAttributeMissing {
            element: ElementName::Autosar,
            attribute: AttributeName::Accesskey,
        });
        test_helper(REQUIRED_ATTRIBUTE_MISSING.as_bytes(), discriminant, true);
    }

    const CHARACTER_CONTENT_FORBIDDEN: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    abcdef"#;

    #[test]
    fn test_character_content_forbidden() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::CharacterContentForbidden {
            element: ElementName::Autosar,
        });
        test_helper(CHARACTER_CONTENT_FORBIDDEN.as_bytes(), discriminant, false);
    }

    const WRONG_ENUM_ITEM_VERSION: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00044.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES>
            <AR-PACKAGE>
                <SHORT-NAME>base</SHORT-NAME>
                <ELEMENTS>
                    <SYSTEM>
                        <SHORT-NAME>System</SHORT-NAME>
                        <FIBEX-ELEMENTS>
                            <FIBEX-ELEMENT-REF-CONDITIONAL>
                                <FIBEX-ELEMENT-REF DEST="SERVICE-INSTANCE-COLLECTION-SET">"#;

    #[test]
    fn test_enum_item_version() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::EnumItemVersionError {
            element: ElementName::Autosar,
            enum_item: EnumItem::Aa,
            version: AutosarVersion::Autosar_00050,
        });
        test_helper(WRONG_ENUM_ITEM_VERSION.as_bytes(), discriminant, false);
    }

    const UNKNOWN_ENUM_ITEM: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES>
            <AR-PACKAGE>
                <SHORT-NAME>base</SHORT-NAME>
                <ELEMENTS>
                    <SYSTEM>
                        <SHORT-NAME>System</SHORT-NAME>
                        <FIBEX-ELEMENTS>
                            <FIBEX-ELEMENT-REF-CONDITIONAL>
                                <FIBEX-ELEMENT-REF DEST="invalid_value_for_the_test">"#;

    #[test]
    fn test_unknown_enum_item() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::UnknownEnumItem { value: "".to_string() });
        test_helper(UNKNOWN_ENUM_ITEM.as_bytes(), discriminant, false);
    }

    const INVALID_ENUM_ITEM: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES>
            <AR-PACKAGE>
                <SHORT-NAME>base</SHORT-NAME>
                <ELEMENTS>
                    <SYSTEM>
                        <SHORT-NAME>System</SHORT-NAME>
                        <FIBEX-ELEMENTS>
                            <FIBEX-ELEMENT-REF-CONDITIONAL>
                                <FIBEX-ELEMENT-REF DEST="default">"#;

    #[test]
    fn test_invalid_enum_item() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::InvalidEnumItem {
            element: ElementName::Abs,
            item: EnumItem::Aa,
        });
        test_helper(INVALID_ENUM_ITEM.as_bytes(), discriminant, false);
    }

    const STRING_VALUE_TOO_LONG: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES><AR-PACKAGE>
            <SHORT-NAME>xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx</SHORT-NAME>
        </AR-PACKAGE></AR-PACKAGES></AUTOSAR>"#;

    #[test]
    fn test_string_value_too_long() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::StringValueTooLong {
            value: "".to_string(),
            length: 1,
        });
        test_helper(STRING_VALUE_TOO_LONG.as_bytes(), discriminant, true);
    }

    const REGEX_MATCH_ERROR: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES><AR-PACKAGE>
            <SHORT-NAME>0a</SHORT-NAME>
        </AR-PACKAGE></AR-PACKAGES></AUTOSAR>"#;

    #[test]
    fn test_regex_match_error() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::RegexMatchError {
            value: "".to_string(),
            regex: "".to_string(),
        });
        test_helper(REGEX_MATCH_ERROR.as_bytes(), discriminant, true);
    }

    const UTF8_ERROR: &[u8] = b"<?xml version=\"1.0\" encoding=\"utf-8\"?>
    <AUTOSAR xsi:schemaLocation=\"http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd\" xmlns=\"http://autosar.org/schema/r4.0\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">
        <AR-PACKAGES><AR-PACKAGE S=\"\xff\xff\">";

    #[test]
    fn test_utf8_error() {
        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), UTF8_ERROR, true);
        let result = parser.parse_arxml();
        assert!(
            matches!(
                result,
                Err(AutosarDataError::ParserError {
                    source: ArxmlParserError::Utf8Error { .. },
                    ..
                })
            ),
            "Did not get the expected parser error"
        );

        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), UTF8_ERROR, false);
        let _ = parser.parse_arxml();
        let warning = parser.warnings.first();
        assert!(
            matches!(
                warning,
                Some(AutosarDataError::ParserError {
                    source: ArxmlParserError::Utf8Error { .. },
                    ..
                })
            ),
            "Did not get the expected parser warning"
        );
    }

    const UNEXPECTED_END_OF_FILE: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">"#;

    #[test]
    fn test_unexpected_end_of_file() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::UnexpectedEndOfFile {
            element: ElementName::Autosar,
        });
        test_helper(UNEXPECTED_END_OF_FILE.as_bytes(), discriminant, false);
    }

    const INVALID_NUMBER: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <AR-PACKAGES><AR-PACKAGE>
        <SHORT-NAME>base</SHORT-NAME>
        <ELEMENTS><I-SIGNAL-I-PDU>
            <SHORT-NAME>Pdu</SHORT-NAME>
            <I-PDU-TIMING-SPECIFICATIONS><I-PDU-TIMING><TRANSMISSION-MODE-DECLARATION><TRANSMISSION-MODE-TRUE-TIMING><CYCLIC-TIMING>
            <TIME-PERIOD><TOLERANCE><ABSOLUTE-TOLERANCE><ABSOLUTE>not a number</ABSOLUTE>"#;

    #[test]
    fn test_invalid_number() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::InvalidNumber { input: "".to_string() });
        test_helper(INVALID_NUMBER.as_bytes(), discriminant, true);
    }

    const ADDITIONAL_DATA: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    </AUTOSAR>
    <extra>"#;

    #[test]
    fn test_additional_data_error() {
        let discriminant = std::mem::discriminant(&ArxmlParserError::AdditionalDataError);
        test_helper(ADDITIONAL_DATA.as_bytes(), discriminant, true);
    }

    #[test]
    fn unescape_entities() {
        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), &[], true);
        let result = parser
            .unescape_string("&amp;&amp;&lt;FOO&gt;&quot;&quot;&apos;&#32;&#x20;end")
            .unwrap();
        assert_eq!(&result, r#"&&<FOO>""'  end"#);
        let result = parser.unescape_string("&amp;&amp;&gt;FOO&lt;&quot&quot;&apos;end");
        assert!(result.is_err());
        // numeric character entity does not accept hex values
        let result = parser.unescape_string("&#abcde;");
        assert!(result.is_err());
        // values from 0x110000 to 0x1FFFFF are not valid unicode code points -> 0x110000 = 1114112
        let result = parser.unescape_string("&#1114112;");
        assert!(result.is_err());
    }

    const PARSER_TEST_DATA: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <!--comment-->
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <!--comment-->
        <AR-PACKAGES>
            <AR-PACKAGE>
                <SHORT-NAME>base</SHORT-NAME>
                <ELEMENTS>
                    <SYSTEM UUID="12345678" S="some string" T="2022-01-31T13:00:59Z">
                        <SHORT-NAME>System</SHORT-NAME>
                        <FIBEX-ELEMENTS>
                            <FIBEX-ELEMENT-REF-CONDITIONAL>
                                <FIBEX-ELEMENT-REF DEST="I-SIGNAL-I-PDU">/base/Pdu</FIBEX-ELEMENT-REF>
                            </FIBEX-ELEMENT-REF-CONDITIONAL>
                        </FIBEX-ELEMENTS>
                    </SYSTEM>
                    <I-SIGNAL-I-PDU>
                        <SHORT-NAME>Pdu</SHORT-NAME>
                        <I-PDU-TIMING-SPECIFICATIONS>
                            <I-PDU-TIMING>
                                <TRANSMISSION-MODE-DECLARATION>
                                    <TRANSMISSION-MODE-TRUE-TIMING>
                                        <CYCLIC-TIMING>
                                            <TIME-PERIOD>
                                                <TOLERANCE>
                                                    <ABSOLUTE-TOLERANCE>
                                                        <ABSOLUTE>1.0</ABSOLUTE>
                                                    </ABSOLUTE-TOLERANCE>
                                                </TOLERANCE>
                                            </TIME-PERIOD>
                                        </CYCLIC-TIMING>
                                    </TRANSMISSION-MODE-TRUE-TIMING>
                                </TRANSMISSION-MODE-DECLARATION>
                            </I-PDU-TIMING>
                        </I-PDU-TIMING-SPECIFICATIONS>
                    </I-SIGNAL-I-PDU>
                </ELEMENTS>
            </AR-PACKAGE>
        </AR-PACKAGES>
    </AUTOSAR>
    "#;

    #[test]
    fn test_basic_functionality() {
        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), PARSER_TEST_DATA.as_bytes(), true);
        let result = parser.parse_arxml();
        assert!(result.is_ok());
    }

    const EMPTY_CHARACTER_DATA: &str = r#"<?xml version="1.0" encoding="utf-8"?>
    <AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AR-PACKAGES>
            <AR-PACKAGE UUID="">
                <SHORT-NAME>x</SHORT-NAME>
            </AR-PACKAGE>
        </AR-PACKAGES>
    </AUTOSAR>
    "#;

    #[test]
    fn test_empty_character_data() {
        let mut parser = ArxmlParser::new(
            PathBuf::from("test_buffer.arxml"),
            EMPTY_CHARACTER_DATA.as_bytes(),
            true,
        );
        let result = parser.parse_arxml();
        assert!(result.is_ok());
    }

    #[test]
    fn chardata_utf8_error() {
        let mut parser = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), b"", true);
        let mut parser_permissive = ArxmlParser::new(PathBuf::from("test_buffer.arxml"), b"", false);

        // correct input for CharacterDataSpec::Pattern
        let pattern_spec = CharacterDataSpec::Pattern {
            check_fn: |_| true,
            regex: "",
            max_length: Some(2),
        };
        let result = parser.parse_character_data(b"ab", &pattern_spec);
        assert!(result.is_ok());

        // trigger the invalid utf-8 error for CharacterDataSpec::Pattern
        let result = parser.parse_character_data(&[0xff], &pattern_spec);
        assert!(result.is_err());

        // permissive parsing allows invalid utf-8 in CharacterDataSpec::Pattern
        let result = parser_permissive.parse_character_data(&[0xff], &pattern_spec);
        assert!(result.is_ok());

        // correct input for CharacterDataSpec::String
        let string_spec = CharacterDataSpec::String {
            max_length: Some(2),
            preserve_whitespace: false,
        };
        let result = parser.parse_character_data(b"ab", &string_spec);
        assert!(result.is_ok());

        // input too long for CharacterDataSpec::String
        let result = parser.parse_character_data(b"abc", &string_spec);
        assert!(result.is_err());

        // trigger the invalid utf-8 error for CharacterDataSpec::String
        let result = parser.parse_character_data(&[0xff], &string_spec);
        assert!(result.is_err());

        // correct conversion for CharacterDataSpec::UnsignedInteger
        let int_spec = CharacterDataSpec::UnsignedInteger;
        let result = parser.parse_character_data(b"123", &int_spec);
        assert!(result.is_ok());

        // conversion error for CharacterDataSpec::UnsignedInteger: valid utf-8, but not a number
        let result = parser.parse_character_data(b"abc", &int_spec);
        assert!(result.is_err());

        // conversion error for CharacterDataSpec::UnsignedInteger: invalid utf-8
        let result = parser.parse_character_data(&[0xff], &int_spec);
        assert!(result.is_err());

        // correct conversion for CharacterDataSpec::Float
        let float_spec = CharacterDataSpec::Float;
        let result = parser.parse_character_data(b"1.0", &float_spec);
        assert!(result.is_ok());

        // conversion error for CharacterDataSpec::Float: valid utf-8, but not a number
        let result = parser.parse_character_data(b"abc", &float_spec);
        assert!(result.is_err());

        // conversion error for CharacterDataSpec::Float: invalid utf-8
        let result = parser.parse_character_data(&[0xff], &float_spec);
        assert!(result.is_err());
    }

    #[test]
    fn test_check_arxml_header() {
        let buffer = "abcde".as_bytes();
        let mut parser = ArxmlParser::new(PathBuf::from("test"), buffer, true);
        assert!(!parser.check_arxml_header());

        let buffer = r#"<?xml version="1.0" encoding="utf-8"?>abcde"#.as_bytes();
        let mut parser = ArxmlParser::new(PathBuf::from("test"), buffer, true);
        assert!(!parser.check_arxml_header());

        let buffer = r#"<?xml version="1.0" encoding="utf-8"?><abcde>"#.as_bytes();
        let mut parser = ArxmlParser::new(PathBuf::from("test"), buffer, true);
        assert!(!parser.check_arxml_header());

        let buffer = r#"<?xml version="1.0" encoding="utf-8"?><AUTOSAR abcde="abcde">"#.as_bytes();
        let mut parser = ArxmlParser::new(PathBuf::from("test"), buffer, true);
        assert!(!parser.check_arxml_header());

        let buffer = r#"<?xml version="1.0" encoding="utf-8"?>
<AUTOSAR>"#
            .as_bytes();
        let mut parser = ArxmlParser::new(PathBuf::from("test"), buffer, true);
        assert!(!parser.check_arxml_header());

        let buffer = r#"<?xml version="1.0" encoding="utf-8"?>
<AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 abcdef" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">"#.as_bytes();
        let mut parser = ArxmlParser::new(PathBuf::from("test"), buffer, true);
        assert!(!parser.check_arxml_header());

        let buffer = r#"<?xml version="1.0" encoding="utf-8"?>
<AUTOSAR xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_00050.xsd" xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">"#.as_bytes();
        let mut parser = ArxmlParser::new(PathBuf::from("test"), buffer, true);
        assert!(parser.check_arxml_header());
    }

    #[test]
    fn parse_attribute_text() {
        let mut parser = ArxmlParser::new(PathBuf::from("test"), &[], true);
        // find the element type of AR-PACKAGE
        let etype_arpackage = ElementType::ROOT
            .find_sub_element(ElementName::ArPackages, u32::MAX)
            .unwrap()
            .0
            .find_sub_element(ElementName::ArPackage, u32::MAX)
            .unwrap()
            .0;

        // whitespace only, should not return an error
        let result = parser.parse_attribute_text(etype_arpackage, br#"   "#);
        assert!(result.is_ok());
        let value = result.unwrap();
        assert!(value.is_empty());

        // invalid string
        let result = parser.parse_attribute_text(etype_arpackage, br#"   abc   "#);
        assert!(result.is_err());

        // invalid attribute name, and no value after the '='
        let result = parser.parse_attribute_text(etype_arpackage, br#"abc="#);
        assert!(result.is_err());

        // Attribute name without a value after the '='
        let result = parser.parse_attribute_text(etype_arpackage, br#"UUID="#);
        assert!(result.is_err());

        // valid UUID attribute
        let value = parser
            .parse_attribute_text(etype_arpackage, br#"UUID="12345678""#)
            .unwrap();
        assert_eq!(value.len(), 1);
        assert_eq!(value[0].attrname, AttributeName::Uuid);

        // whitespace after the attribute value
        let value = parser
            .parse_attribute_text(etype_arpackage, br#"UUID="12345678"   "#)
            .unwrap();
        assert_eq!(value.len(), 1);

        // junk after the attribute value
        let result = parser.parse_attribute_text(etype_arpackage, br#"UUID="12345678"   abc   "#);
        assert!(result.is_err());

        // attribute enclosed in single quotes
        let value = parser
            .parse_attribute_text(etype_arpackage, br#"UUID='12345678'"#)
            .unwrap();
        assert_eq!(value.len(), 1);

        // missing final quote
        let result = parser.parse_attribute_text(etype_arpackage, br#"UUID='12345678"#);
        assert!(result.is_err());

        // mixed quotes ' -> ", error
        let result = parser.parse_attribute_text(etype_arpackage, br#"UUID='12345678""#);
        assert!(result.is_err());

        // two attributes without whitespace between them
        let result = parser.parse_attribute_text(etype_arpackage, br#"UUID="12345678"T="2024-01-01""#);
        assert!(result.is_err());

        // two attributes with whitespace between them
        let value = parser
            .parse_attribute_text(etype_arpackage, br#"UUID="12345678" T="2024-01-01""#)
            .unwrap();
        assert_eq!(value.len(), 2);

        // two attributes with extra whitespace between them
        let value = parser
            .parse_attribute_text(etype_arpackage, br#"UUID="12345678"  T="2024-01-01""#)
            .unwrap();
        assert_eq!(value.len(), 2);

        // two attributes with leading whitespace and extra whitespace between them
        let value = parser
            .parse_attribute_text(etype_arpackage, br#"  UUID="12345678"  T="2024-01-01""#)
            .unwrap();
        assert_eq!(value.len(), 2);
    }
}