fix(instance): isSoftDelete true after creating (#10799)

lib/model.js

@@ -4057,7 +4057,7 @@ class Model {
 
     const deletedAtAttribute = this.constructor.rawAttributes[this.constructor._timestampAttributes.deletedAt];
     const defaultValue = deletedAtAttribute.hasOwnProperty('defaultValue') ? deletedAtAttribute.defaultValue : null;
-    const deletedAt = this.get(this.constructor._timestampAttributes.deletedAt);
+    const deletedAt = this.get(this.constructor._timestampAttributes.deletedAt) || null;
     const isSet = deletedAt !== defaultValue;
 
     return isSet;

test/integration/instance.test.js

@@ -594,6 +594,12 @@ describe(Support.getTestDialectTeaser('Instance'), () => {
       return this.ParanoidUser.sync({ force: true });
     });
 
+    it('should return false when model is just created', function() {
+      return this.ParanoidUser.create({ username: 'foo' }).then(user => {
+        expect(user.isSoftDeleted()).to.be.false;
+      });
+    });
+
     it('returns false if user is not soft deleted', function() {
       return this.ParanoidUser.create({ username: 'fnord' }).then(() => {
         return this.ParanoidUser.findAll().then(users => {