vld 0.5.1

Type-safe runtime validation library for Rust, inspired by Zod
Documentation 
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use serde_json::Value;
use std::collections::HashSet;

use crate::error::{IssueCode, PathSegment, SizeOrigin, VldError};
use crate::schema::VldSchema;

/// Schema for validating a JSON array into a `HashSet` (unique elements).
///
/// Created via [`vld::set()`](crate::set).
///
/// Duplicates (after validation) are silently merged, so the generated JSON
/// Schema does **not** declare `uniqueItems` (duplicate input is valid).
///
/// # Example
/// ```ignore
/// let schema = vld::set(vld::string().min(1));
/// // Input: ["a", "b", "a"]
/// // Output: HashSet { "a", "b" }
/// ```
pub struct ZSet<T: VldSchema> {
    element: T,
    min_size: Option<usize>,
    max_size: Option<usize>,
}

impl<T: VldSchema> ZSet<T> {
    /// Create the schema (the same as its `vld::` constructor function).
    pub fn new(element: T) -> Self {
        Self {
            element,
            min_size: None,
            max_size: None,
        }
    }

    /// Minimum number of unique elements.
    pub fn min_size(mut self, n: usize) -> Self {
        self.min_size = Some(n);
        self
    }

    /// Maximum number of unique elements.
    pub fn max_size(mut self, n: usize) -> Self {
        self.max_size = Some(n);
        self
    }
}

impl<T> VldSchema for ZSet<T>
where
    T: VldSchema,
    T::Output: Eq + std::hash::Hash,
{
    type Output = HashSet<T::Output>;

    fn parse_value(&self, value: &Value) -> Result<Self::Output, VldError> {
        let arr = value
            .as_array()
            .ok_or_else(|| crate::primitives::type_error(&None, "array", value))?;

        let mut result = HashSet::new();
        let mut errors = VldError::new();
        // An inner `Err` may carry no issues: track failure, not issue count.
        let mut failed = false;

        for (i, item) in arr.iter().enumerate() {
            match self.element.parse_value(item) {
                Ok(v) => {
                    result.insert(v);
                }
                Err(e) => {
                    failed = true;
                    errors = errors.merge(e.with_prefix(PathSegment::Index(i)));
                }
            }
        }

        if let Some(min) = self.min_size {
            if result.len() < min {
                errors.push_code(IssueCode::TooSmall {
                    origin: SizeOrigin::Set,
                    minimum: min.into(),
                    inclusive: true,
                });
            }
        }

        if let Some(max) = self.max_size {
            if result.len() > max {
                errors.push_code(IssueCode::TooBig {
                    origin: SizeOrigin::Set,
                    maximum: max.into(),
                    inclusive: true,
                });
            }
        }

        if errors.is_empty() && !failed {
            Ok(result)
        } else {
            Err(errors)
        }
    }
}

/// `min_size` becomes `minItems` (n unique items need at least n items);
/// `max_size` is *not* emitted as `maxItems`, because duplicates in the
/// input are allowed and do not count towards the limit. The bound is
/// exposed as `x-maxUniqueItems` instead.
#[cfg(feature = "openapi")]
impl<T> crate::openapi::JsonSchema for ZSet<T>
where
    T: VldSchema + crate::openapi::JsonSchema,
    T::Output: Eq + std::hash::Hash,
{
    fn json_schema(&self) -> serde_json::Value {
        let mut schema = serde_json::json!({
            "type": "array",
            "items": self.element.json_schema(),
        });
        if let Some(min) = self.min_size {
            // `minItems` counts duplicates too; generators need the distinct count.
            schema["minItems"] = serde_json::json!(min);
            schema["x-minUniqueItems"] = serde_json::json!(min);
        }
        if let Some(max) = self.max_size {
            schema["x-maxUniqueItems"] = serde_json::json!(max);
        }
        schema
    }
}

#[cfg(feature = "openapi")]
impl<T> crate::openapi::CollectNestedSchemas for ZSet<T>
where
    T: VldSchema + crate::openapi::CollectNestedSchemas,
    T::Output: Eq + std::hash::Hash,
{
    fn collect_nested_schemas(&self, out: &mut Vec<crate::schema::NestedSchemaEntry>) {
        self.element.collect_nested_schemas(out);
    }
}