feat: add graphql support

crates/mcpaas-mapping/src/execute.rs

@@ -69,20 +69,7 @@ fn empty_target_context(context: MappingTargetContext) -> Value {
 }
 
 fn read_path<'a>(value: &'a Value, path: &JsonPath) -> Option<&'a Value> {
-    let mut current = value;
-
-    for field in path.root.root_fields() {
-        current = current.get(*field)?;
-    }
-
-    for segment in &path.segments {
-        current = match segment {
-            JsonPathSegment::Field(field) => current.get(field)?,
-            JsonPathSegment::Index(index) => current.get(*index)?,
-        };
-    }
-
-    Some(current)
+    path.read(value)
 }
 
 fn write_path(target: &mut Value, path: &JsonPath, value: Value) -> Result<(), MappingError> {

crates/mcpaas-mapping/src/jsonpath.rs

@@ -1,3 +1,5 @@
+use serde_json::Value;
+
 use crate::MappingError;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -103,6 +105,23 @@ impl JsonPath {
 
         path
     }
+
+    pub fn read<'a>(&self, value: &'a Value) -> Option<&'a Value> {
+        let mut current = value;
+
+        for field in self.root.root_fields() {
+            current = current.get(*field)?;
+        }
+
+        for segment in &self.segments {
+            current = match segment {
+                JsonPathSegment::Field(field) => current.get(field)?,
+                JsonPathSegment::Index(index) => current.get(*index)?,
+            };
+        }
+
+        Some(current)
+    }
 }
 
 fn match_root(input: &str) -> Option<(JsonPathRoot, &str)> {