Implemented findDerivedDefs routine

lib/utils/SchemaManager.js

@@ -156,4 +156,27 @@ export default class SchemaManager {
     return tag2MethodMapping;
   }
 
+  findDerivedDefinitions(defPointer) {
+    let definition = this.byPointer(defPointer);
+
+    // FIXME maybe not throw?
+    if (!definition.discriminator) return [];
+
+    let globalDefs = this._schema.definitions || {};
+    let res = [];
+    for (let defName of Object.keys(globalDefs)) {
+      if (!globalDefs[defName].allOf) continue;
+
+      let subTypes = globalDefs[defName].allOf;
+      let idx = subTypes.findIndex((subType) => {
+        if (subType.$ref === defPointer) return true;
+        return false;
+      });
+      if (idx < 0) continue;
+
+      res.push(defName);
+    }
+    return res;
+  }
+
 }

tests/schemas/extended-petstore.json

@@ -772,8 +772,12 @@
     },
     "Pet": {
       "type": "object",
-      "required": ["name", "photoUrls"],
+      "required": ["name", "photoUrls", "petType"],
+      "discriminator": "petType",
       "properties": {
+        "petType": {
+          "type": "string"
+        },
         "id": {
           "type": "integer",
           "format": "int64"
@@ -815,6 +819,33 @@
         "name": "Pet"
       }
     },
+    "Cat": {
+      "description": "A representation of a cat",
+      "allOf": [
+        {
+          "type": "object",
+          "properties": {
+            "huntingSkill": {
+              "type": "string",
+              "description": "The measured skill for hunting",
+              "default": "lazy",
+              "enum": [
+                "clueless",
+                "lazy",
+                "adventurous",
+                "aggressive"
+              ]
+            }
+          },
+          "required": [
+            "huntingSkill"
+          ]
+        },
+        {
+          "$ref": "#/definitions/Pet"
+        },
+      ]
+    },
     "ApiResponse": {
       "type": "object",
       "properties": {

tests/unit/SchemaManager.spec.js

@@ -225,5 +225,27 @@ describe('Utils', () => {
       });
     });
 
+    describe('findDerivedDefinitions method', () => {
+      beforeAll((done) => {
+        schemaMgr.load('/tests/schemas/extended-petstore.json').then(() => {
+          done();
+        }, () => {
+          done(new Error('Error handler should not be called'));
+        });
+      });
+
+      it('should find derived definitions for Pet', () => {
+        let deriveDefs = schemaMgr.findDerivedDefinitions('#/definitions/Pet');
+        deriveDefs.should.be.instanceof(Array);
+        deriveDefs.should.not.be.empty;
+        deriveDefs.should.be.deepEqual(['Cat']);
+      });
+
+      it('should return emtpy array for definitions that dont have discriminator', () => {
+        let deriveDefs = schemaMgr.findDerivedDefinitions('#/definitions/Order');
+        deriveDefs.should.be.instanceof(Array);
+        deriveDefs.should.be.empty;
+      });
+    });
   });
 });