feat: Initial handling of if keyword

src/keywords/if_.rs

@@ -0,0 +1,74 @@
+use crate::helpers::is;
+use jsonschema_equivalent_rule_processor_logger::log_processing;
+use serde_json::Value;
+
+/// Simplify `if` keyword group by embedding the content of `then` or `else` schema
+/// into `allOf` in case of deterministic validation or removing it if `then` or `else` are missing.
+#[log_processing(cfg(feature = "logging"))]
+pub(crate) fn simplify_if(schema: &mut Value) -> bool {
+    let schema_object = if let Some(value) = schema.as_object_mut() {
+        value
+    } else {
+        return false;
+    };
+
+    if let Some(if_schema) = schema_object.get("if") {
+        if is::false_schema(if_schema) {
+            // In case of a `false` schema we know that the `then` schema will never be considered
+            // so we can simplify the schema by ensuring that the `else` schema has to be verified
+            let _ = schema_object.remove("if");
+            let _ = schema_object.remove("then");
+            if let Some(else_schema) = schema_object.remove("else") {
+                if let Value::Array(mut all_of_items) = schema_object
+                    .remove("allOf")
+                    .unwrap_or_else(|| Value::Array(Vec::with_capacity(1)))
+                {
+                    all_of_items.push(else_schema);
+                    let _ = schema_object.insert("allOf".to_string(), Value::Array(all_of_items));
+                }
+            }
+            true
+        } else if is::true_schema(if_schema) {
+            // In case of a `true` schema we know that the `then` schema will never be considered
+            // so we can simplify the schema by ensuring that the `then` schema has to be verified
+            let _ = schema_object.remove("if");
+            let _ = schema_object.remove("else");
+            if let Some(else_schema) = schema_object.remove("then") {
+                if let Value::Array(mut all_of_items) = schema_object
+                    .remove("allOf")
+                    .unwrap_or_else(|| Value::Array(Vec::with_capacity(1)))
+                {
+                    all_of_items.push(else_schema);
+                    let _ = schema_object.insert("allOf".to_string(), Value::Array(all_of_items));
+                }
+            }
+            true
+        } else if !schema_object.contains_key("else") && !schema_object.contains_key("then") {
+            let _ = schema_object.remove("if");
+            true
+        } else {
+            false
+        }
+    } else {
+        false
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::simplify_if;
+    use serde_json::{json, Value};
+    use test_case::test_case;
+
+    #[test_case(json!({}) => json!({}))]
+    #[test_case(json!({"if": false, "then": {"minLength": 0}, "else": {"maxLength": 0}}) => json!({"allOf": [{"maxLength": 0}]}))]
+    #[test_case(json!({"if": true, "then": {"minLength": 0}, "else": {"maxLength": 0}}) => json!({"allOf": [{"minLength": 0}]}))]
+    #[test_case(json!({"if": {"type": "string"}, "then": {"minLength": 0}, "else": {"maxLength": 0}}) => json!({"if": {"type": "string"}, "then": {"minLength": 0}, "else": {"maxLength": 0}}))]
+    #[test_case(json!({"if": false}) => json!({}))]
+    #[test_case(json!({"if": true}) => json!({}))]
+    #[test_case(json!({"if": {"type": "string"}}) => json!({}))]
+    fn test_simplify_if(mut value: Value) -> Value {
+        let _ = simplify_if(&mut value);
+        value
+    }
+}

src/keywords/mod.rs

@@ -3,6 +3,7 @@
 mod additional_properties;
 mod const_;
 mod enum_;
+mod if_;
 mod macro_;
 mod property_names;
 mod required;
@@ -28,11 +29,11 @@ static UPDATE_SCHEMA_METHODS: &[fn(&mut Value) -> bool] = &[
     additional_properties::remove_empty_additional_properties,
     const_::simple_const_cleanup,
     enum_::simple_enum_cleanup,
+    if_::simplify_if,
     macro_::maximum_minimum_related_keywords::update_max_min_related_keywords,
     property_names::optimise_property_names,
     required::remove_empty_required,
     type_::optimise_keyword_type,
-    type_::remove_extraneous_keys_keyword_type,
 ];
 
 /// Perform the schema optimisaton without descending the schema

tests/all_rules.rs

@@ -6,7 +6,7 @@ use std::str::FromStr;
 
 /// This method does expose the one-liner pretty-print value of a given JSON value
 /// Respect the default `Value::to_string` method this ensures that the separators (`:` and `,`) have a space after
-/// NOTE: The code is far from being good looking or performing, but this is mostly used to esure that all_rules.md has
+/// NOTE: The code is far from being good looking or performing, but this is mostly used to esure that `all_rules.md` has
 /// considently formatted JSON fields
 fn pretty_format_json_value(value: &Value) -> String {
     value.to_string().replace(":", ": ").replace(",", ", ")