Fixes #2885 duplicate sessions

spec/ParseUser.spec.js

@@ -1168,6 +1168,36 @@ describe('Parse.User testing', () => {
     });
   });
 
+  it('only creates a single session for an installation / user pair (#2885)', done => {
+    Parse.Object.disableSingleInstance();
+    const provider = getMockFacebookProvider();
+    Parse.User._registerAuthenticationProvider(provider);
+    Parse.User.logInWith('facebook', {
+      success: () => {
+        return Parse.User.logInWith('facebook', {
+          success: () => {
+            return Parse.User.logInWith('facebook', {
+              success: (user) => {
+                const sessionToken = user.getSessionToken();
+                const query = new Parse.Query('_Session');
+                return query.find({ useMasterKey: true })
+                  .then((results) => {
+                    expect(results.length).toBe(1);
+                    expect(results[0].get('sessionToken')).toBe(sessionToken);
+                    expect(results[0].get('createdWith')).toEqual({
+                      action: 'login',
+                      authProvider: 'facebook'
+                    });
+                    done();
+                  }).catch(done.fail);
+              }
+            });
+          }
+        });
+      }
+    });
+  });
+
   it('log in with provider with files', done => {
     const provider = getMockFacebookProvider();
     Parse.User._registerAuthenticationProvider(provider);

src/RestWrite.js

@@ -568,7 +568,7 @@ RestWrite.prototype.createSessionToken = function() {
       objectId: this.objectId()
     },
     createdWith: {
-      'action': 'signup',
+      'action': this.storage['authProvider'] ? 'login' : 'signup',
       'authProvider': this.storage['authProvider'] || 'password'
     },
     restricted: false,
@@ -578,8 +578,18 @@ RestWrite.prototype.createSessionToken = function() {
   if (this.response && this.response.response) {
     this.response.response.sessionToken = token;
   }
-  var create = new RestWrite(this.config, Auth.master(this.config), '_Session', null, sessionData);
-  return create.execute();
+
+  // Destroy the sessions in 'Background'
+  this.config.database.destroy('_Session', {
+    user: {
+      __type: 'Pointer',
+      className: '_User',
+      objectId: this.objectId()
+    },
+    installationId: this.auth.installationId,
+    sessionToken: { '$ne': token },
+  });
+  return new RestWrite(this.config, Auth.master(this.config), '_Session', null, sessionData).execute();
 }
 
 // Handles any followup logic