miden_assembly_syntax/ast/path/

path_buf.rs

use alloc::string::{String, ToString};
use core::{
    fmt,
    ops::Deref,
    str::{self, FromStr},
};

use miden_core::serde::{
    ByteReader, ByteWriter, Deserializable, DeserializationError, Serializable,
};

use super::{Path, PathComponent, PathError};
use crate::ast::Ident;

// ITEM PATH
// ================================================================================================

/// Path to an item in a library, i.e. module, procedure, constant or type.
#[derive(Default, Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[cfg_attr(
    all(feature = "arbitrary", test),
    miden_test_serde_macros::serde_test(binary_serde(true))
)]
pub struct PathBuf {
    pub(super) inner: String,
}

impl Deref for PathBuf {
    type Target = Path;

    #[inline(always)]
    fn deref(&self) -> &Self::Target {
        self.as_ref()
    }
}

impl AsRef<Path> for PathBuf {
    #[inline(always)]
    fn as_ref(&self) -> &Path {
        Path::new(&self.inner)
    }
}

impl AsRef<str> for PathBuf {
    #[inline(always)]
    fn as_ref(&self) -> &str {
        &self.inner
    }
}

impl<'a> From<&'a Path> for PathBuf {
    #[inline(always)]
    fn from(path: &'a Path) -> Self {
        path.to_path_buf()
    }
}

/// Constructors
impl PathBuf {
    /// Get an empty [PathBuf] with `capacity` bytes allocated for the underlying path storage
    pub fn with_capacity(capacity: usize) -> Self {
        Self { inner: String::with_capacity(capacity) }
    }

    /// Returns a new path created from the provided source.
    ///
    /// A path consists of at list of components separated by `::` delimiter. A path must contain
    /// at least one component.
    ///
    /// # Errors
    ///
    /// Returns an error if:
    ///
    /// * The path is empty.
    /// * Any component of the path is empty.
    /// * Any component is not a valid identifier (quoted or unquoted) in Miden Assembly syntax,
    ///   i.e. starts with an ASCII alphabetic character, contains only printable ASCII characters,
    ///   except for `::`, which must only be used as a path separator.
    pub fn new<S>(source: &S) -> Result<Self, PathError>
    where
        S: AsRef<str> + ?Sized,
    {
        let source = source.as_ref();

        let validated = Path::validate(source)?;

        validated.canonicalize()
    }

    /// Extends this [PathBuf] from a collection of possibly-invalid path components
    pub(super) fn extend_with_components<'a>(
        &mut self,
        components: impl IntoIterator<Item = Result<PathComponent<'a>, PathError>>,
    ) -> Result<(), PathError> {
        for component in components {
            self.push_component(component?.as_str());
        }
        Ok(())
    }

    /// Create an absolute [Path] from a pre-validated string
    pub fn absolute<S>(source: &S) -> Self
    where
        S: AsRef<str> + ?Sized,
    {
        let source = source.as_ref();
        Path::new(source).to_absolute().unwrap().into_owned()
    }

    /// Create a relative [Path] from a pre-validated string
    pub fn relative<S>(source: &S) -> Self
    where
        S: AsRef<str> + ?Sized,
    {
        let source = source.as_ref();
        match source.strip_prefix("::") {
            Some(rest) => Self { inner: rest.to_string() },
            None => Self { inner: source.to_string() },
        }
    }

    /// Get a [Path] corresponding to the this [PathBuf]
    #[inline]
    pub fn as_path(&self) -> &Path {
        self.as_ref()
    }

    /// Convert this mutable [PathBuf] into an owned, read-only [`alloc::boxed::Box<Path>`]
    pub fn into_boxed_path(self) -> alloc::boxed::Box<Path> {
        let inner = self.inner.into_boxed_str();
        let inner = alloc::boxed::Box::into_raw(inner);
        // SAFETY: This cast is safe because *mut Path is equivalent to *mut str
        unsafe { alloc::boxed::Box::from_raw(inner as *mut Path) }
    }
}

/// Mutation
impl PathBuf {
    /// Overrides the parent prefix of this path.
    ///
    /// The parent prefix is the part of the path consisting of all components but the last one.
    ///
    /// If there is only a single component in `self`, this function is equivalent to appending
    /// `self` to `parent`.
    pub fn set_parent<P>(&mut self, parent: &P)
    where
        P: AsRef<Path> + ?Sized,
    {
        let parent = parent.as_ref();
        match self.split_last() {
            Some((last, _)) => {
                let reparented = parent.join(last);
                let _ = core::mem::replace(self, reparented);
            },
            None => {
                self.inner.clear();
                self.inner.push_str(parent.as_str());
            },
        }
    }

    /// Extends `self` with `path`
    ///
    /// If `path` is absolute, it replaces the current path.
    ///
    /// This function ensures that the joined path correctly delimits each path component, and that
    /// each component is in canonical form.
    pub fn push<P>(&mut self, path: &P)
    where
        P: AsRef<Path> + ?Sized,
    {
        let path = path.as_ref();

        self.extend_with_components(path.components()).expect("invalid path");
    }

    /// Extends `self` with `component`.
    ///
    /// Unlike [`Self::push`], which appends another `Path` to the buffer - this method appends the
    /// given string as a single path component, ensuring that the content is quoted properly if
    /// needed.
    ///
    /// If `::` is pushed, it is treated as a literal root component (i.e. it makes the path
    /// absolute). On a non-empty [PathBuf], this has the effect of clearing the path, similar to
    /// what happens if you call [`PathBuf::push`] with an absolute path.
    ///
    /// Pushing components using this method guarantees they are in canonical form.
    pub fn push_component<S>(&mut self, component: &S)
    where
        S: AsRef<str> + ?Sized,
    {
        let component = component.as_ref();
        match component {
            "" | "\"\"" => (),
            "::" if self.inner.is_empty() => {
                self.inner.push_str("::");
            },
            "::" => {
                // Pushing the root component on a non-empty path, resets it to an empty absolute
                // path
                self.inner.clear();
                self.inner.push_str("::");
            },
            component => {
                // Add a delimiter if the path is non-empty
                if !self.is_empty() {
                    self.inner.push_str("::");
                }

                let is_quoted = component.starts_with('"') && component.ends_with('"');
                let is_special = component == Path::KERNEL_PATH || component == Path::EXEC_PATH;
                let requires_quoting = !is_special && Ident::requires_quoting(component);

                if is_special && self.inner.is_empty() {
                    // Special namespaces are always absolute
                    self.inner.push_str("::");
                    self.inner.push_str(component);
                } else if requires_quoting && !is_quoted {
                    // Quote when necessary
                    self.inner.push('"');
                    self.inner.push_str(component);
                    self.inner.push('"');
                } else if !requires_quoting && is_quoted {
                    // Unquote unnecessary quoting
                    self.inner.push_str(&component[1..(component.len() - 1)]);
                } else {
                    // No quoting required, or already quoted
                    self.inner.push_str(component);
                }
            },
        }
    }

    /// Truncates `self` to [`Path::parent`].
    ///
    /// Returns `false` if `self.parent()` is `None`, otherwise `true`.
    pub fn pop(&mut self) -> bool {
        match self.parent() {
            Some(parent) => {
                let buf = parent.as_str().to_string();
                self.inner = buf;
                true
            },
            None => false,
        }
    }
}

impl<'a> core::ops::AddAssign<&'a Path> for PathBuf {
    fn add_assign(&mut self, rhs: &'a Path) {
        self.push(rhs);
    }
}

impl<'a> core::ops::AddAssign<&'a str> for PathBuf {
    fn add_assign(&mut self, rhs: &'a str) {
        self.push_component(rhs);
    }
}

impl<'a> core::ops::AddAssign<&'a Ident> for PathBuf {
    fn add_assign(&mut self, rhs: &'a Ident) {
        self.push_component(rhs.as_str());
    }
}

impl<'a> core::ops::AddAssign<&'a crate::ast::ProcedureName> for PathBuf {
    fn add_assign(&mut self, rhs: &'a crate::ast::ProcedureName) {
        self.push_component(rhs.as_str());
    }
}

impl<'a> TryFrom<&'a str> for PathBuf {
    type Error = PathError;

    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
        PathBuf::new(value)
    }
}

fn is_canonical_path(path: &Path) -> bool {
    let mut is_absolute = false;
    let mut saw_normal_component = false;

    for component in path.components() {
        let component = match component {
            Ok(component) => component,
            Err(_) => return false,
        };

        match component {
            PathComponent::Root => is_absolute = true,
            component @ PathComponent::Normal(_) => {
                let is_quoted = component.is_quoted();
                let component = component.as_str();
                let is_special = matches!(component, Path::KERNEL_PATH | Path::EXEC_PATH);
                let requires_quoting = !is_special && Ident::requires_quoting(component);

                if !saw_normal_component && !is_absolute && is_special {
                    return false;
                }

                if requires_quoting != is_quoted {
                    return false;
                }

                saw_normal_component = true;
            },
        }
    }

    true
}

impl TryFrom<String> for PathBuf {
    type Error = PathError;

    fn try_from(value: String) -> Result<Self, Self::Error> {
        let path = Path::validate(&value)?;
        if is_canonical_path(path) {
            Ok(Self { inner: value })
        } else {
            path.canonicalize()
        }
    }
}

impl From<Ident> for PathBuf {
    fn from(component: Ident) -> Self {
        let mut buf = PathBuf::with_capacity(component.as_str().len());
        buf.push_component(component.as_str());
        buf
    }
}

impl From<PathBuf> for String {
    fn from(path: PathBuf) -> Self {
        path.inner
    }
}

impl From<PathBuf> for alloc::sync::Arc<Path> {
    fn from(value: PathBuf) -> Self {
        value.into_boxed_path().into()
    }
}

impl From<alloc::borrow::Cow<'_, Path>> for PathBuf {
    fn from(value: alloc::borrow::Cow<'_, Path>) -> Self {
        value.into_owned()
    }
}

impl FromStr for PathBuf {
    type Err = PathError;

    #[inline]
    fn from_str(value: &str) -> Result<Self, Self::Err> {
        Self::new(value)
    }
}

impl Serializable for PathBuf {
    fn write_into<W: ByteWriter>(&self, target: &mut W) {
        self.as_path().write_into(target);
    }
}

impl Serializable for Path {
    fn write_into<W: ByteWriter>(&self, target: &mut W) {
        target.write_u16(self.byte_len().try_into().expect("invalid path: too long"));
        target.write_bytes(self.as_str().as_bytes());
    }
}

impl Deserializable for PathBuf {
    fn read_from<R: ByteReader>(source: &mut R) -> Result<Self, DeserializationError> {
        let len = source.read_u16()? as usize;
        let path = source.read_slice(len)?;
        let path =
            str::from_utf8(path).map_err(|e| DeserializationError::InvalidValue(e.to_string()))?;
        let path =
            Path::validate(path).map_err(|e| DeserializationError::InvalidValue(e.to_string()))?;
        path.canonicalize()
            .map_err(|e| DeserializationError::InvalidValue(e.to_string()))
    }
}

#[cfg(feature = "serde")]
impl serde::Serialize for PathBuf {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        serializer.serialize_str(self.inner.as_str())
    }
}

#[cfg(feature = "serde")]
impl<'de> serde::Deserialize<'de> for PathBuf {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        use serde::de::Visitor;

        struct PathVisitor;

        impl<'de> Visitor<'de> for PathVisitor {
            type Value = PathBuf;

            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                formatter.write_str("a valid Path/PathBuf")
            }

            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
            where
                E: serde::de::Error,
            {
                Path::validate(v)
                    .map_err(serde::de::Error::custom)?
                    .canonicalize()
                    .map_err(serde::de::Error::custom)
            }

            fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
            where
                E: serde::de::Error,
            {
                Path::validate(&v)
                    .map_err(serde::de::Error::custom)?
                    .canonicalize()
                    .map_err(serde::de::Error::custom)
            }
        }

        deserializer.deserialize_any(PathVisitor)
    }
}

impl fmt::Display for PathBuf {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fmt::Display::fmt(self.as_path(), f)
    }
}

// TESTS
// ================================================================================================

/// Tests
#[cfg(test)]
mod tests {
    use alloc::string::String;
    use core::assert_matches;

    use super::{PathBuf, PathError};
    use crate::{Path, PathComponent, ast::IdentError};

    #[test]
    fn single_component_path() {
        let path = PathBuf::new("foo").unwrap();
        assert!(!path.is_absolute());
        assert_eq!(path.components().count(), 1);
        assert_eq!(path.last(), Some("foo"));
        assert_eq!(path.first(), Some("foo"));
    }

    #[test]
    fn relative_path_two_components() {
        let path = PathBuf::new("foo::bar").unwrap();
        assert!(!path.is_absolute());
        assert_eq!(path.components().count(), 2);
        assert_eq!(path.last(), Some("bar"));
        assert_eq!(path.first(), Some("foo"));
    }

    #[test]
    fn relative_path_three_components() {
        let path = PathBuf::new("foo::bar::baz").unwrap();
        assert!(!path.is_absolute());
        assert_eq!(path.components().count(), 3);
        assert_eq!(path.last(), Some("baz"));
        assert_eq!(path.first(), Some("foo"));
        assert_eq!(path.parent().map(Path::as_str), Some("foo::bar"));
    }

    #[test]
    fn single_quoted_component() {
        let path = PathBuf::new("\"miden::base/account@0.1.0\"").unwrap();
        assert!(!path.is_absolute());
        assert_eq!(path.components().count(), 1);
        assert_eq!(path.last(), Some("miden::base/account@0.1.0"));
        assert_eq!(path.first(), Some("miden::base/account@0.1.0"));
    }

    #[test]
    fn trailing_quoted_component() {
        let path = PathBuf::new("foo::\"miden::base/account@0.1.0\"").unwrap();
        assert!(!path.is_absolute());
        assert_eq!(path.components().count(), 2);
        assert_eq!(path.last(), Some("miden::base/account@0.1.0"));
        assert_eq!(path.first(), Some("foo"));
    }

    #[test]
    fn interspersed_quoted_component() {
        let path = PathBuf::new("foo::\"miden::base/account@0.1.0\"::item").unwrap();
        assert!(!path.is_absolute());
        assert_eq!(path.components().count(), 3);
        assert_eq!(path.last(), Some("item"));
        assert_eq!(path.first(), Some("foo"));
        assert_eq!(path.parent().map(Path::as_str), Some("foo::\"miden::base/account@0.1.0\""));
    }

    #[test]
    fn mixed_quoted_components_regression() {
        let component = "::root_ns:root@1.0.0";
        let module = "abi_transform_tx_kernel_get_inputs_4";
        let function = "miden::protocol::active_note::get_inputs";
        let quoted_function = "\"miden::protocol::active_note::get_inputs\"";

        let p1 = PathBuf::new(&format!("{component}::{module}::\"{function}\"")).unwrap();
        let mut p2 = PathBuf::new(component).unwrap();
        p2.push_component(module);
        p2.push_component(function);

        assert_eq!(p1, p2);

        // Forward iteration of path components

        let mut p1components = p1.components();
        let mut p2components = p2.components();

        let p1root = p1components.next().unwrap().unwrap();
        let p2root = p2components.next().unwrap().unwrap();

        assert_eq!(p1root, PathComponent::Root);
        assert_eq!(p1root, p2root);

        let p1component = p1components.next().unwrap().unwrap();
        let p2component = p2components.next().unwrap().unwrap();

        assert_eq!(p1component, PathComponent::Normal("\"root_ns:root@1.0.0\""));
        assert_eq!(p1component, p2component);

        let p1module = p1components.next().unwrap().unwrap();
        let p2module = p2components.next().unwrap().unwrap();

        assert_eq!(p1module, PathComponent::Normal(module));
        assert_eq!(p1module, p2module);

        let p1function = p1components.next().unwrap().unwrap();
        let p2function = p2components.next().unwrap().unwrap();

        assert_eq!(p1function, PathComponent::Normal(quoted_function));
        assert_eq!(p1function, p2function);

        // Backward iteration of path components

        let mut p1components = p1.components();
        let mut p2components = p2.components();

        let p1function = p1components.next_back().unwrap().unwrap();
        let p2function = p2components.next_back().unwrap().unwrap();

        assert_eq!(p1function, PathComponent::Normal(quoted_function));
        assert_eq!(p1function, p2function);

        let p1module = p1components.next_back().unwrap().unwrap();
        let p2module = p2components.next_back().unwrap().unwrap();

        assert_eq!(p1module, PathComponent::Normal(module));
        assert_eq!(p1module, p2module);

        let p1component = p1components.next_back().unwrap().unwrap();
        let p2component = p2components.next_back().unwrap().unwrap();

        assert_eq!(p1component, PathComponent::Normal("\"root_ns:root@1.0.0\""));
        assert_eq!(p1component, p2component);

        let p1root = p1components.next_back().unwrap().unwrap();
        let p2root = p2components.next_back().unwrap().unwrap();

        assert_eq!(p1root, PathComponent::Root);
        assert_eq!(p1root, p2root);

        assert!(p1.is_absolute());
        assert_eq!(p1.components().count(), 4);
        assert_eq!(p1.last(), Some(function));
        assert_eq!(p1.first(), Some("root_ns:root@1.0.0"));
        let parent = p1.parent().unwrap();
        assert_eq!(
            parent.as_str(),
            "::\"root_ns:root@1.0.0\"::abi_transform_tx_kernel_get_inputs_4"
        );
        assert_eq!(parent.parent().map(Path::as_str), Some("::\"root_ns:root@1.0.0\""));

        assert!(p2.is_absolute());
        assert_eq!(p2.components().count(), 4);
        assert_eq!(p2.last(), Some(function));
        assert_eq!(p2.first(), Some("root_ns:root@1.0.0"));
        let parent = p2.parent().unwrap();
        assert_eq!(
            parent.as_str(),
            "::\"root_ns:root@1.0.0\"::abi_transform_tx_kernel_get_inputs_4"
        );
        assert_eq!(parent.parent().map(Path::as_str), Some("::\"root_ns:root@1.0.0\""));
    }

    #[test]
    fn try_from_string_canonicalizes_like_str() {
        let from_str = PathBuf::try_from("foo::\"bar\"").unwrap();
        let from_string = PathBuf::try_from(String::from("foo::\"bar\"")).unwrap();

        assert_eq!(from_string, from_str);
        assert_eq!(from_string.as_str(), "foo::bar");
    }

    #[test]
    fn try_from_string_reuses_canonical_allocation() {
        let value = String::from("foo::bar");
        let original_ptr = value.as_ptr();
        let original_capacity = value.capacity();

        let path = PathBuf::try_from(value).unwrap();

        assert_eq!(path.as_str(), "foo::bar");
        assert_eq!(path.inner.as_ptr(), original_ptr);
        assert_eq!(path.inner.capacity(), original_capacity);
    }

    #[test]
    fn exec_path() {
        let path = PathBuf::new("$exec::bar::baz").unwrap();
        assert!(path.is_absolute());
        assert_eq!(path.components().count(), 4);
        assert_eq!(path.last(), Some("baz"));
        assert_eq!(path.first(), Some("$exec"));
    }

    #[test]
    fn kernel_path() {
        let path = PathBuf::new("$kernel::bar::baz").unwrap();
        assert!(path.is_absolute());
        assert_eq!(path.components().count(), 4);
        assert_eq!(path.last(), Some("baz"));
        assert_eq!(path.first(), Some("$kernel"));
    }

    #[test]
    fn invalid_path_empty() {
        let result = Path::validate("");
        assert_matches!(result, Err(PathError::Empty));
    }

    #[test]
    fn invalid_path_empty_component() {
        let result = Path::validate("::");
        assert_matches!(result, Err(PathError::EmptyComponent));
    }

    #[test]
    fn invalid_path_trailing_delimiter() {
        let result = Path::validate("foo::");
        assert_matches!(result, Err(PathError::InvalidComponent(IdentError::Empty)));
    }

    #[test]
    fn invalid_path_invalid_character() {
        let result = Path::validate("#foo::bar");
        assert_matches!(result, Err(PathError::InvalidComponent(IdentError::InvalidChars { .. })));
    }

    #[cfg(feature = "serde")]
    #[test]
    fn serde_deserialize_path_buf_canonicalizes_redundant_quotes() {
        let path: PathBuf = serde_json::from_str(r#""\"foo\"::\"bar\"""#)
            .expect("path deserialization must succeed");
        assert_eq!(path.as_str(), "foo::bar");
    }

    #[cfg(feature = "serde")]
    #[test]
    fn serde_deserialize_path_buf_preserves_required_quotes() {
        let path: PathBuf = serde_json::from_value(serde_json::Value::String(String::from(
            "::foo::\"miden::base/account@0.1.0\"",
        )))
        .expect("path deserialization must succeed");
        assert_eq!(path.as_str(), "::foo::\"miden::base/account@0.1.0\"");
    }

    #[cfg(feature = "serde")]
    #[test]
    fn serde_deserialize_path_buf_rejects_overflow_after_canonicalization() {
        let component = format!("{}-", "a".repeat(254));
        let mut source = String::new();
        for i in 0..255 {
            if i > 0 {
                source.push_str("::");
            }
            source.push_str(&component);
        }

        let err = serde_json::from_value::<PathBuf>(serde_json::Value::String(source))
            .expect_err("deserialization must fail when canonicalization exceeds u16::MAX bytes");
        let message = format!("{err}");
        assert!(message.contains("too long"), "unexpected error: {message}");
    }
}