Add Schema methods insert, get and remove

These are just convenience methods that delegate to the inner object. `insert` will also convert bool schemas to object schemas.

docs/0-migrating.md

@@ -129,9 +129,7 @@ pub struct MyTransform;
 impl Transform for MyTransform {
     fn transform(&mut self, schema: &mut Schema) {
         // First, make our change to this schema
-        if let Some(obj) = schema.as_object_mut() {
+        schema.insert("my_property".to_string(), serde_json::json!("hello world"));
-            obj.insert("my_property".to_string(), serde_json::json!("hello world"));
-        }
 
         // Then apply the transform to any subschemas
         transform_subschemas(self, schema);
@@ -147,9 +145,7 @@ Also, since `Transform` is now implemented for functions that take a single `&mu
 ```rust
 fn my_transform(schema: &mut Schema) {
     // First, make our change to this schema
-    if let Some(obj) = schema.as_object_mut() {
+    schema.insert("my_property".to_string(), serde_json::json!("hello world"));
-        obj.insert("my_property".to_string(), serde_json::json!("hello world"));
-    }
 
     // Then apply the transform to any subschemas
     transform_subschemas(&mut my_transform, schema);
@@ -165,9 +161,7 @@ Finally, you can also use the `RecursiveTransform` newtype to convert a non-recu
 
 ```rust
 fn my_transform2(schema: &mut Schema) {
-    if let Some(obj) = schema.as_object_mut() {
+    schema.insert("my_property".to_string(), serde_json::json!("hello world"));
-        obj.insert("my_property".to_string(), serde_json::json!("hello world"));
-    }
 }
 
 let mut schema = schemars::schema_for!(str);

docs/_includes/examples/schemars_attrs.rs

@@ -25,9 +25,7 @@ pub enum MyEnum {
 }
 
 fn remove_format(schema: &mut Schema) {
-    if let Some(obj) = schema.as_object_mut() {
+    schema.remove("format");
-        obj.remove("format");
-    }
 }
 
 fn main() {

schemars/examples/schemars_attrs.rs

@@ -25,9 +25,7 @@ pub enum MyEnum {
 }
 
 fn remove_format(schema: &mut Schema) {
-    if let Some(obj) = schema.as_object_mut() {
+    schema.remove("format");
-        obj.remove("format");
-    }
 }
 
 fn main() {

schemars/src/_private/mod.rs

@@ -20,9 +20,7 @@ pub fn json_schema_for_flatten<T: ?Sized + JsonSchema>(
     let mut schema = T::_schemars_private_non_optional_json_schema(generator);
 
     if T::_schemars_private_is_option() && !required {
-        if let Some(object) = schema.as_object_mut() {
+        schema.remove("required");
-            object.remove("required");
-        }
     }
 
     // Always allow aditional/unevaluated properties, because the outer struct determines
@@ -33,16 +31,14 @@ pub fn json_schema_for_flatten<T: ?Sized + JsonSchema>(
 }
 
 fn allow_unknown_properties(schema: &mut Schema) {
-    if let Some(obj) = schema.as_object_mut() {
+    if schema.get("additionalProperties").and_then(Value::as_bool) == Some(false) {
-        if obj.get("additionalProperties").and_then(Value::as_bool) == Some(false) {
+        schema.remove("additionalProperties");
-            obj.remove("additionalProperties");
-        }
-        if obj.get("unevaluatedProperties").and_then(Value::as_bool) == Some(false) {
-            obj.remove("unevaluatedProperties");
-        }
-
-        transform_immediate_subschemas(&mut allow_unknown_properties, schema);
     }
+    if schema.get("unevaluatedProperties").and_then(Value::as_bool) == Some(false) {
+        schema.remove("unevaluatedProperties");
+    }
+
+    transform_immediate_subschemas(&mut allow_unknown_properties, schema);
 }
 
 /// Hack to simulate specialization:
@@ -211,7 +207,7 @@ pub fn apply_inner_validation(schema: &mut Schema, f: fn(&mut Schema) -> ()) {
     if let Some(inner_schema) = schema
         .as_object_mut()
         .and_then(|o| o.get_mut("items"))
-        .and_then(|i| <&mut Schema>::try_from(i).ok())
+        .and_then(|i| i.try_into().ok())
     {
         f(inner_schema);
     }

schemars/src/schema.rs

@@ -138,10 +138,80 @@ impl Schema {
             self.0 = Value::Object(map);
         }
 
-        self.as_object_mut()
+        self.0
+            .as_object_mut()
             .expect("Schema value should be of type Object.")
     }
 
+    /// Inserts a property into the schema, replacing any previous value.
+    ///
+    /// If the schema wraps a bool value, it will first be converted into an equivalent object schema.
+    ///
+    /// If the schema did not have this key present, `None` is returned.
+    ///
+    /// If the schema did have this key present, the value is updated, and the old value is returned.
+    ///
+    /// # Example
+    /// ```
+    /// use schemars::json_schema;
+    /// use serde_json::json;
+    ///
+    /// let mut schema = json_schema!(true);
+    /// assert_eq!(schema.insert("type".to_owned(), "array".into()), None);
+    /// assert_eq!(schema.insert("type".to_owned(), "object".into()), Some(json!("array")));
+    ///
+    /// assert_eq!(schema, json_schema!({"type": "object"}));
+    /// ```
+    pub fn insert(&mut self, k: String, v: Value) -> Option<Value> {
+        self.ensure_object().insert(k, v)
+    }
+
+    /// If the `Schema`'s underlying JSON value is an object, gets a reference to that object's value for the given key.
+    ///
+    /// This always returns `None` for bool schemas.
+    ///
+    /// # Example
+    /// ```
+    /// use schemars::json_schema;
+    /// use serde_json::json;
+    ///
+    /// let obj_schema = json_schema!({"type": "array"});
+    /// assert_eq!(obj_schema.get("type"), Some(&json!("array")));
+    /// assert_eq!(obj_schema.get("format"), None);
+    ///
+    /// let bool_schema = json_schema!(true);
+    /// assert_eq!(bool_schema.get("type"), None);
+    /// ```
+    pub fn get<Q>(&self, key: &Q) -> Option<&Value>
+    where
+        String: core::borrow::Borrow<Q>,
+        Q: ?Sized + Ord + Eq + core::hash::Hash,
+    {
+        self.0.as_object().and_then(|o| o.get(key))
+    }
+
+    /// If the `Schema`'s underlying JSON value is an object, removes and returns its value for the given key.
+    ///
+    /// This always returns `None` for bool schemas, without modifying them.
+    ///
+    /// # Example
+    /// ```
+    /// use schemars::json_schema;
+    /// use serde_json::json;
+    ///
+    /// let mut schema = json_schema!({"type": "array"});
+    /// assert_eq!(schema.remove("type"), Some(json!("array")));
+    /// assert_eq!(schema, json_schema!({}));
+    ///
+    /// ```
+    pub fn remove<Q>(&mut self, key: &Q) -> Option<Value>
+    where
+        String: core::borrow::Borrow<Q>,
+        Q: ?Sized + Ord + Eq + core::hash::Hash,
+    {
+        self.0.as_object_mut().and_then(|o| o.remove(key))
+    }
+
     pub(crate) fn has_type(&self, ty: &str) -> bool {
         match self.0.get("type") {
             Some(Value::Array(values)) => values.iter().any(|v| v.as_str() == Some(ty)),

schemars/src/transform.rs

@@ -21,9 +21,7 @@ pub struct MyTransform;
 impl Transform for MyTransform {
     fn transform(&mut self, schema: &mut Schema) {
         // First, make our change to this schema
-        if let Some(obj) = schema.as_object_mut() {
+        schema.insert("my_property".to_string(), "hello world".into());
-            obj.insert("my_property".to_string(), serde_json::json!("hello world"));
-        }
 
         // Then apply the transform to any subschemas
         transform_subschemas(self, schema);
@@ -55,9 +53,7 @@ The same example with a `fn` transform:
 use schemars::transform::transform_subschemas;
 
 fn add_property(schema: &mut Schema) {
-    if let Some(obj) = schema.as_object_mut() {
+    schema.insert("my_property".to_string(), "hello world".into());
-        obj.insert("my_property".to_string(), serde_json::json!("hello world"));
-    }
 
     transform_subschemas(&mut add_property, schema)
 }
@@ -87,9 +83,7 @@ And the same example using a closure wrapped in a `RecursiveTransform`:
 use schemars::transform::{Transform, RecursiveTransform};
 
 let mut transform = RecursiveTransform(|schema: &mut Schema| {
-    if let Some(obj) = schema.as_object_mut() {
+    schema.insert("my_property".to_string(), "hello world".into());
-        obj.insert("my_property".to_string(), serde_json::json!("hello world"));
-    }
 });
 
 let mut schema = json_schema!({
@@ -236,9 +230,7 @@ pub(crate) fn transform_immediate_subschemas<T: Transform + ?Sized>(
 /// use schemars::transform::{Transform, RecursiveTransform};
 ///
 /// let mut transform = RecursiveTransform(|schema: &mut Schema| {
-///     if let Some(obj) = schema.as_object_mut() {
+///     schema.insert("my_property".to_string(), "hello world".into());
-///         obj.insert("my_property".to_string(), serde_json::json!("hello world"));
-///     }
 /// });
 ///
 /// let mut schema = json_schema!({
@@ -289,9 +281,7 @@ impl Transform for ReplaceBoolSchemas {
                 if let Some((ap_key, ap_value)) = obj.remove_entry("additionalProperties") {
                     transform_subschemas(self, schema);
 
-                    if let Some(obj) = schema.as_object_mut() {
+                    schema.insert(ap_key, ap_value);
-                        obj.insert(ap_key, ap_value);
-                    }
 
                     return;
                 }
@@ -339,11 +329,9 @@ impl Transform for SetSingleExample {
     fn transform(&mut self, schema: &mut Schema) {
         transform_subschemas(self, schema);
 
-        if let Some(obj) = schema.as_object_mut() {
+        if let Some(Value::Array(examples)) = schema.remove("examples") {
-            if let Some(Value::Array(examples)) = obj.remove("examples") {
+            if let Some(first_example) = examples.into_iter().next() {
-                if let Some(first_example) = examples.into_iter().next() {
+                schema.insert("example".into(), first_example);
-                    obj.insert("example".into(), first_example);
-                }
             }
         }
     }
@@ -360,10 +348,8 @@ impl Transform for ReplaceConstValue {
     fn transform(&mut self, schema: &mut Schema) {
         transform_subschemas(self, schema);
 
-        if let Some(obj) = schema.as_object_mut() {
+        if let Some(value) = schema.remove("const") {
-            if let Some(value) = obj.remove("const") {
+            schema.insert("enum".into(), Value::Array(vec![value]));
-                obj.insert("enum".into(), Value::Array(vec![value]));
-            }
         }
     }
 }
@@ -381,13 +367,11 @@ impl Transform for ReplacePrefixItems {
     fn transform(&mut self, schema: &mut Schema) {
         transform_subschemas(self, schema);
 
-        if let Some(obj) = schema.as_object_mut() {
+        if let Some(prefix_items) = schema.remove("prefixItems") {
-            if let Some(prefix_items) = obj.remove("prefixItems") {
+            let previous_items = schema.insert("items".to_owned(), prefix_items);
-                let previous_items = obj.insert("items".to_owned(), prefix_items);
 
-                if let Some(previous_items) = previous_items {
+            if let Some(previous_items) = previous_items {
-                    obj.insert("additionalItems".to_owned(), previous_items);
+                schema.insert("additionalItems".to_owned(), previous_items);
-                }
             }
         }
     }
@@ -400,14 +384,11 @@ impl Transform for ReplaceUnevaluatedProperties {
     fn transform(&mut self, schema: &mut Schema) {
         transform_subschemas(self, schema);
 
-        let Some(obj) = schema.as_object_mut() else {
+        let Some(up) = schema.remove("unevaluatedProperties") else {
-            return;
-        };
-        let Some(up) = obj.remove("unevaluatedProperties") else {
             return;
         };
 
-        obj.insert("additionalProperties".to_owned(), up);
+        schema.insert("additionalProperties".to_owned(), up);
 
         let mut gather_property_names = GatherPropertyNames::default();
         gather_property_names.transform(schema);

schemars/tests/transform.rs

@@ -1,24 +1,20 @@
 mod util;
 use schemars::{transform::RecursiveTransform, JsonSchema, Schema};
-use serde_json::Value;
+use serde_json::{Map, Value};
 use util::*;
 
 fn capitalize_type(schema: &mut Schema) {
-    if let Some(obj) = schema.as_object_mut() {
+    if let Some(Value::String(ty)) = schema.get("type") {
-        if let Some(Value::String(ty)) = obj.get("type") {
+        schema.insert("upperType".to_owned(), ty.to_uppercase().into());
-            obj.insert("upperType".to_owned(), ty.to_uppercase().into());
-        }
     }
 }
 
 fn insert_property_count(schema: &mut Schema) {
-    if let Some(obj) = schema.as_object_mut() {
+    let count = schema
-        let count = obj
+        .get("properties")
-            .get("properties")
+        .and_then(Value::as_object)
-            .and_then(|p| p.as_object())
+        .map_or(0, Map::len);
-            .map_or(0, |p| p.len());
+    schema.insert("propertyCount".to_owned(), count.into());
-        obj.insert("propertyCount".to_owned(), count.into());
-    }
 }
 
 #[allow(dead_code)]