IsTest Annotation

Use the isTest annotation to define classes and methods that only contain code used for testing your application. The isTest annotation on methods is equivalent to the testMethod keyword.

Classes defined with the isTest annotation don't count against your organization limit of 3 MB for all Apex code.

Note

Classes and methods defined as isTest can be either private or public. Classes defined as isTest must be top-level classes.

This is an example of a private test class that contains two test methods.

This is an example of a public test class that contains utility methods for test data creation:

Classes defined as isTest can't be interfaces or enums.

Methods of a public test class can only be called from a running test, that is, a test method or code invoked by a test method, and can't be called by a non-test request.. To learn about the various ways you can run test methods, see Running Unit Test Methods.

IsTest(SeeAllData=true) Annotation

For Apex code saved using Salesforce API version 24.0 and later, use the isTest(SeeAllData=true) annotation to grant test classes and individual test methods access to all data in the organization, including pre-existing data that the test didn’t create. Starting with Apex code saved using Salesforce API version 24.0, test methods don’t have access by default to pre-existing data in the organization. However, test code saved against Salesforce API version 23.0 and earlier continues to have access to all data in the organization and its data access is unchanged. See Isolation of Test Data from Organization Data in Unit Tests.

Considerations for the IsTest(SeeAllData=true) Annotation

If a test class is defined with the isTest(SeeAllData=true) annotation, this annotation applies to all its test methods whether the test methods are defined with the @isTest annotation or the testmethod keyword.
The isTest(SeeAllData=true) annotation is used to open up data access when applied at the class or method level. However, using isTest(SeeAllData=false) on a method doesn’t restrict organization data access for that method if the containing class has already been defined with the isTest(SeeAllData=true) annotation. In this case, the method will still have access to all the data in the organization.

This example shows how to define a test class with the isTest(SeeAllData=true) annotation. All the test methods in this class have access to all data in the organization.

This second example shows how to apply the isTest(SeeAllData=true) annotation on a test method. Because the class that the test method is contained in isn’t defined with this annotation, you have to apply this annotation on the test method to enable access to all data for that test method. The second test method doesn’t have this annotation, so it can access only the data it creates in addition to objects that are used to manage your organization, such as users.

IsTest(OnInstall=true) Annotation

Use the IsTest(OnInstall=true) annotation to specify which Apex tests are executed during package installation. This annotation is used for tests in managed or unmanaged packages. Only test methods with this annotation, or methods that are part of a test class that has this annotation, will be executed during package installation. Tests annotated to run during package installation must pass in order for the package installation to succeed. It is no longer possible to bypass a failing test during package installation. A test method or a class that doesn't have this annotation, or that is annotated with isTest(OnInstall=false) or isTest, won't be executed during installation.

This example shows how to annotate a test method that will be executed during package installation. In this example, test1 will be executed but test2 and test3 won't.