jsonschema-rs/jsonschema/src/compilation/mod.rs

306 lines
11 KiB
Rust

//! Schema compilation.
//! The main idea is to compile the input JSON Schema to a validators tree that will contain
//! everything needed to perform such validation in runtime.
pub(crate) mod context;
pub(crate) mod options;
use crate::{
error::ErrorIterator,
keywords,
output::Output,
paths::{InstancePath, JSONPointer},
primitive_type::{PrimitiveType, PrimitiveTypesBitMap},
schema_node::SchemaNode,
validator::Validate,
Draft, ValidationError,
};
use ahash::AHashMap;
use context::CompilationContext;
use once_cell::sync::Lazy;
use options::CompilationOptions;
use serde_json::Value;
use std::sync::Arc;
use url::Url;
pub(crate) const DEFAULT_ROOT_URL: &str = "json-schema:///";
/// The structure that holds a JSON Schema compiled into a validation tree
#[derive(Debug)]
pub struct JSONSchema {
pub(crate) node: SchemaNode,
config: Arc<CompilationOptions>,
}
pub(crate) static DEFAULT_SCOPE: Lazy<Url> =
Lazy::new(|| url::Url::parse(DEFAULT_ROOT_URL).expect("Is a valid URL"));
impl JSONSchema {
/// Return a default `CompilationOptions` that can configure
/// `JSONSchema` compilaton flow.
///
/// Using options you will be able to configure the draft version
/// to use during `JSONSchema` compilation
///
/// Example of usage:
/// ```rust
/// # use crate::jsonschema::{Draft, JSONSchema};
/// # let schema = serde_json::json!({});
/// let maybe_jsonschema: Result<JSONSchema, _> = JSONSchema::options()
/// .with_draft(Draft::Draft7)
/// .compile(&schema);
/// ```
#[must_use]
pub fn options() -> CompilationOptions {
CompilationOptions::default()
}
/// Compile the input schema into a validation tree.
///
/// The method is equivalent to `JSONSchema::options().compile(schema)`
pub fn compile(schema: &Value) -> Result<JSONSchema, ValidationError> {
Self::options().compile(schema)
}
/// Run validation against `instance` and return an iterator over `ValidationError` in the error case.
#[inline]
pub fn validate<'instance>(
&'instance self,
instance: &'instance Value,
) -> Result<(), ErrorIterator<'instance>> {
let instance_path = InstancePath::new();
let mut errors = self.node.validate(instance, &instance_path).peekable();
if errors.peek().is_none() {
Ok(())
} else {
Err(Box::new(errors))
}
}
/// Run validation against `instance` but return a boolean result instead of an iterator.
/// It is useful for cases, where it is important to only know the fact if the data is valid or not.
/// This approach is much faster, than `validate`.
#[must_use]
#[inline]
pub fn is_valid(&self, instance: &Value) -> bool {
self.node.is_valid(instance)
}
/// Apply the schema and return an `Output`. No actual work is done at this point, the
/// evaluation of the schema is deferred until a method is called on the `Output`. This is
/// because different output formats will have different performance characteristics.
///
/// # Examples
///
/// "basic" output format
///
/// ```rust
/// # use crate::jsonschema::{Draft, JSONSchema, output::{Output, BasicOutput}};
/// let schema_json = serde_json::json!({
/// "title": "string value",
/// "type": "string"
/// });
/// let instance = serde_json::json!{"some string"};
/// let schema = JSONSchema::options().compile(&schema_json).unwrap();
/// let output: BasicOutput = schema.apply(&instance).basic();
/// let output_json = serde_json::to_value(output).unwrap();
/// assert_eq!(output_json, serde_json::json!({
/// "valid": true,
/// "annotations": [
/// {
/// "keywordLocation": "",
/// "instanceLocation": "",
/// "annotations": {
/// "title": "string value"
/// }
/// }
/// ]
/// }));
/// ```
#[must_use]
pub const fn apply<'a, 'b>(&'a self, instance: &'b Value) -> Output<'a, 'b> {
Output::new(self, &self.node, instance)
}
/// The [`Draft`] which this schema was compiled against
#[must_use]
pub fn draft(&self) -> Draft {
self.config.draft()
}
/// The [`CompilationOptions`] that were used to compile this schema
#[must_use]
pub fn config(&self) -> Arc<CompilationOptions> {
Arc::clone(&self.config)
}
}
/// Compile JSON schema into a tree of validators.
#[inline]
pub(crate) fn compile_validators<'a, 'c>(
schema: &'a Value,
context: &'c CompilationContext,
) -> Result<SchemaNode, ValidationError<'a>> {
let context = context.push(schema)?;
let relative_path = context.clone().into_pointer();
match schema {
Value::Bool(value) => match value {
true => Ok(SchemaNode::new_from_boolean(&context, None)),
false => Ok(SchemaNode::new_from_boolean(
&context,
Some(
keywords::boolean::FalseValidator::compile(relative_path)
.expect("Should always compile"),
),
)),
},
Value::Object(object) => {
if let Some(reference) = object.get("$ref") {
let unmatched_keywords = object
.iter()
.filter_map(|(k, v)| {
if k.as_str() == "$ref" {
None
} else {
Some((k.clone(), v.clone()))
}
})
.collect();
let mut validators = Vec::new();
if let Value::String(reference) = reference {
let validator = keywords::ref_::compile(schema, reference, &context)
.expect("Should always return Some")?;
validators.push(("$ref".to_string(), validator));
Ok(SchemaNode::new_from_keywords(
&context,
validators,
Some(unmatched_keywords),
))
} else {
Err(ValidationError::single_type_error(
JSONPointer::default(),
relative_path,
reference,
PrimitiveType::String,
))
}
} else {
let mut validators = Vec::with_capacity(object.len());
let mut unmatched_keywords = AHashMap::new();
let mut is_if = false;
let mut is_props = false;
for (keyword, subschema) in object {
if keyword == "if" {
is_if = true;
}
if keyword == "properties"
|| keyword == "additionalProperties"
|| keyword == "patternProperties"
{
is_props = true;
}
if let Some(validator) = context
.config
.draft()
.get_validator(keyword)
.and_then(|f| f(object, subschema, &context))
{
validators.push((keyword.clone(), validator?));
} else {
unmatched_keywords.insert(keyword.to_string(), subschema.clone());
}
}
if is_if {
unmatched_keywords.remove("then");
unmatched_keywords.remove("else");
}
if is_props {
unmatched_keywords.remove("additionalProperties");
unmatched_keywords.remove("patternProperties");
unmatched_keywords.remove("properties");
}
let unmatched_keywords = if unmatched_keywords.is_empty() {
None
} else {
Some(unmatched_keywords)
};
Ok(SchemaNode::new_from_keywords(
&context,
validators,
unmatched_keywords,
))
}
}
_ => Err(ValidationError::multiple_type_error(
JSONPointer::default(),
relative_path,
schema,
PrimitiveTypesBitMap::new()
.add_type(PrimitiveType::Boolean)
.add_type(PrimitiveType::Object),
)),
}
}
#[cfg(test)]
mod tests {
use super::JSONSchema;
use crate::error::ValidationError;
use serde_json::{from_str, json, Value};
use std::{fs::File, io::Read, path::Path};
fn load(path: &str, idx: usize) -> Value {
let path = Path::new(path);
let mut file = File::open(path).unwrap();
let mut content = String::new();
file.read_to_string(&mut content).ok().unwrap();
let data: Value = from_str(&content).unwrap();
let case = &data.as_array().unwrap()[idx];
case.get("schema").unwrap().clone()
}
#[test]
fn only_keyword() {
// When only one keyword is specified
let schema = json!({"type": "string"});
let compiled = JSONSchema::compile(&schema).unwrap();
let value1 = json!("AB");
let value2 = json!(1);
// And only this validator
assert_eq!(compiled.node.validators().len(), 1);
assert!(compiled.validate(&value1).is_ok());
assert!(compiled.validate(&value2).is_err());
}
#[test]
fn validate_ref() {
let schema = load("tests/suite/tests/draft7/ref.json", 1);
let value = json!({"bar": 3});
let compiled = JSONSchema::compile(&schema).unwrap();
assert!(compiled.validate(&value).is_ok());
let value = json!({"bar": true});
assert!(compiled.validate(&value).is_err());
}
#[test]
fn wrong_schema_type() {
let schema = json!([1]);
let compiled = JSONSchema::compile(&schema);
assert!(compiled.is_err());
}
#[test]
fn multiple_errors() {
let schema = json!({"minProperties": 2, "propertyNames": {"minLength": 3}});
let value = json!({"a": 3});
let compiled = JSONSchema::compile(&schema).unwrap();
let result = compiled.validate(&value);
let errors: Vec<ValidationError> = result.unwrap_err().collect();
assert_eq!(errors.len(), 2);
assert_eq!(
errors[0].to_string(),
r#"{"a":3} has less than 2 properties"#
);
assert_eq!(errors[1].to_string(), r#""a" is shorter than 3 characters"#);
}
}