Added support for anyOf and oneOf keywords in validation flow

lib/schemaUtils.js

@@ -2986,7 +2986,8 @@ module.exports = {
 
       // This is dereferenced schema (converted to JSON schema for validation)
       schema = deref.resolveRefs(openApiSchemaObj, parameterSourceOption, components,
-        schemaCache.schemaResolutionCache, PROCESSING_TYPE.VALIDATION, 'example', 0, {}, options.stackLimit);
+        schemaCache.schemaResolutionCache, PROCESSING_TYPE.VALIDATION, 'example', 0, {}, options.stackLimit),
+      compositeSchema = schema.oneOf || schema.anyOf;
 
     if (needJsonMatching) {
       try {
@@ -3001,8 +3002,29 @@ module.exports = {
       }
     }
 
+    // For anyOf and oneOf schemas, validate value against each schema and report result with least mismatches
+    if (compositeSchema) {
+      // get mismatches of value against each schema
+      async.map(compositeSchema, (elementSchema, cb) => {
+        setTimeout(() => {
+          this.checkValueAgainstSchema(property, jsonPathPrefix, txnParamName, value,
+            `${schemaPathPrefix}.${schema.oneOf ? 'oneOf' : 'anyOf'}[${_.findIndex(compositeSchema, elementSchema)}]`,
+            elementSchema, parameterSourceOption, components, options, schemaCache, cb);
+        }, 0);
+      }, (err, results) => {
+        let sortedResults;
+
+        if (err) {
+          return callback(err, []);
+        }
+
+        // return mismatches of schema against which least validation mismatches were found
+        sortedResults = _.sortBy(results, (res) => { return res.length; });
+        return callback(null, sortedResults[0]);
+      });
+    }
     // When processing a reference, schema.type could also be undefined
-    if (schema && schema.type) {
+    else if (schema && schema.type) {
       if (typeof schemaTypeToJsValidator[schema.type] === 'function') {
         let isCorrectType;
 
@@ -3168,6 +3190,7 @@ module.exports = {
             return callback(null, mismatches);
           }
           // result passed. No AJV mismatch
+          return callback(null, []);
         }
 
         // Schema was not AJV or object
@@ -3186,15 +3209,20 @@ module.exports = {
             }
           }]);
         }
+        else {
+          return callback(null, []);
+        }
       }
       else {
         // unknown schema.type found
         // TODO: Decide how to handle. Log?
+        return callback(null, []);
       }
     }
     // Schema not defined
-    return callback(null, []);
-
+    else {
+      return callback(null, []);
+    }
     // if (!schemaTypeToJsValidator[schema.type](value)) {
     //   callback(null, [{
     //     property,