Added support for OAuth2 flows

Author: SahilChoudhary22

lib/schemaUtils.js

@@ -75,6 +75,12 @@ const { formatDataPath, checkIsCorrectType, isKnownType } = require('./common/sc
     VALIDATION: 'VALIDATION',
     CONVERSION: 'CONVERSION'
   },
+  FLOW_TYPE = {
+    authorizationCode: 'authorization_code',
+    implicit: 'implicit',
+    password: 'password_credentials',
+    clientCredentials: 'client_credentials'
+  },
 
   // These are the methods supported in the PathItem schema
   // https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#pathItemObject
@@ -1110,8 +1116,87 @@ module.exports = {
       }
       else if (securityDef.type === 'oauth2') {
         helper = {
-          type: 'oauth2'
+          type: 'oauth2',
+          oauth2: []
         };
+
+        let flowObj, currentFlowType, flowCollectionIdentifier;
+        if (securityDef.flows) {
+          /*
+          //===================[]========================\\
+          ||  OAuth2 Flow Name || Key name in collection ||
+          |]===================[]========================[|
+          || clientCredentials || client_credentials     ||
+          || password          || password_credentials   ||
+          || implicit          || implicit               ||
+          || authorizationCode || authorization_code     ||
+          \\===================[]========================//
+          Ref : https://swagger.io/docs/specification/authentication/oauth2/
+
+
+          Other flow types in collection
+          • "authorization_code_with_pkce"
+
+          */
+          if (securityDef.flows.hasOwnProperty('clientCredentials')) {
+            currentFlowType = FLOW_TYPE.clientCredentials;
+            flowObj = _.get(securityDef, 'flows.clientCredentials');
+          }
+          else if (securityDef.flows.hasOwnProperty('authorizationCode')) {
+            currentFlowType = FLOW_TYPE.authorizationCode;
+            flowObj = _.get(securityDef, 'flows.authorizationCode');
+          }
+          else if (securityDef.flows.hasOwnProperty('password')) {
+            currentFlowType = FLOW_TYPE.password;
+            flowObj = _.get(securityDef, 'flows.password');
+          }
+          else if (securityDef.flows.hasOwnProperty('implicit')) {
+            currentFlowType = FLOW_TYPE.implicit;
+            flowObj = _.get(securityDef, 'flows.implicit');
+          }
+        }
+
+        if (currentFlowType) { // Means the flow is of supported type
+
+          // Fields supported by all flows -> refreshUrl, scopes
+          if (!_.isEmpty(flowObj.scope)) {
+            helper.oauth2.push({
+              key: 'scope',
+              value: _.isString(flowObj.scopes) ? flowObj.scopes : ''
+            });
+          }
+
+          /* refreshURL is indicated by key 'redirect_uri' in collection
+          Ref : https://stackoverflow.com/a/42131366/19078409 */
+          if (!_.isEmpty(flowObj.refreshUrl)) {
+            helper.oauth2.push({
+              key: 'redirect_uri',
+              value: _.isString(flowObj.refreshUrl) ? flowObj.refreshUrl : ''
+            });
+          }
+
+          // Fields supported by all flows except implicit -> tokenUrl
+          if (currentFlowType !== FLOW_TYPE.implicit) {
+            helper.oauth2.push({
+              key: 'accessTokenUrl',
+              value: _.isString(flowObj.tokenUrl) ? flowObj.tokenUrl : '<Access Token URL>'
+            });
+          }
+
+          // Fields supported by all flows all except password, clientCredentials -> authorizationUrl
+          if (currentFlowType !== FLOW_TYPE.password && currentFlowType !== FLOW_TYPE.clientCredentials) {
+            helper.oauth2.push({
+              key: 'authUrl',
+              value: _.isString(flowObj.authUrl) ? flowObj.authUrl : '<Auth URL>'
+            });
+          }
+
+          flowCollectionIdentifier = {
+            key: 'grant_type',
+            value: currentFlowType
+          };
+          helper.oauth2.push(flowCollectionIdentifier);
+        }
       }
       else if (securityDef.type === 'apiKey') {
         helper = {