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Assert Class

Contains methods to assert various conditions with test methods, such as whether two values are the same, a condition is true, or a variable is null.

Namespace

System

Assert Methods

The following are methods for Assert.

areEqual(expected, actual, msg)

Asserts that the first two arguments are the same.

Signature

public static void areEqual(Object expected, Object actual, String msg)

Parameters

  • expected: Type: Object Expected value.
  • actual: Type: Object Actual value.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the first two arguments aren't the same, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String sub = 'abcde'.substring(2);
Assert.areEqual('cde', sub, 'Expected characters after first two'); // Succeeds

areEqual(expected, actual)

Asserts that the two arguments are the same.

Signature

public static void areEqual(Object expected, Object actual)

Parameters

  • expected: Type: Object Expected value.
  • actual: Type: Object Actual value.

Return Value

Type: void

Usage

If the two arguments aren't the same, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String sub = 'abcde'.substring(2);
Assert.areEqual('cde', sub); // Succeeds

areNotEqual(notExpected, actual, msg)

Asserts that the first two arguments aren’t the same.

Signature

public static void areNotEqual(Object notExpected, Object actual, String msg)

Parameters

  • notExpected: Type: Object Value that’s not expected.
  • actual: Type: Object Actual value.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the first two arguments are the same, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String sub = 'abcde'.substring(2);
Assert.areNotEqual('xyz', sub, 'Characters not expected after first two'); // Succeeds

areNotEqual(notExpected, actual)

Asserts that the two arguments aren’t the same.

Signature

public static void areNotEqual(Object notExpected, Object actual)

Parameters

  • notExpected: Type: Object Value that’s not expected.
  • actual: Type: Object Actual value.

Return Value

Type: void

Usage

If the two arguments are the same, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String sub = 'abcde'.substring(2);
Assert.areNotEqual('xyz', sub); // Succeeds

fail(msg)

Immediately return a fatal error that causes code execution to halt.

Signature

public static void fail(String msg)

Parameters

  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

Commonly used in a try/catch block test case where an exception is expected to be thrown. You can’t, however, catch the assertion failure in the try/catch block even though it’s logged as an exception.

Example

// test case where exception is expected
try {
    SomeClass.methodUnderTest();
    Assert.fail('DmlException Expected');
} catch (DmlException ex) {
    // Add assertions here about the expected exception
}

fail()

Immediately return a fatal error that causes code execution to halt.

Signature

public static void fail()

Return Value

Type: void

Usage

Commonly used in a try/catch block test case where an exception is expected to be thrown. You can’t, however, catch the assertion failure in the try/catch block even though it’s logged as an exception.

Example

// test case where exception is expected
try {
    SomeClass.methodUnderTest();
    Assert.fail(); 
} catch (DmlException ex) {
    // Add assertions here about the expected exception
}

isFalse(condition, msg)

Asserts that the specified condition is false.

Signature

public static void isFalse(Boolean condition, String msg)

Parameters

  • condition: Type: Boolean Condition you’re checking to determine if it’s false.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the condition is true, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Boolean containsCode = 'Salesforce'.contains('code');
Assert.isFalse(containsCode, 'No code'); // Assertion succeeds

isFalse(condition)

Asserts that the specified condition is false.

Signature

public static void isFalse(Boolean condition)

Parameters

  • condition: Type: Boolean Condition you’re checking to determine if it’s false.

Return Value

Type: void

Usage

If the condition is true, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Boolean containsCode = 'Salesforce'.contains('code');
Assert.isFalse(containsCode); // Assertion succeeds

isInstanceOfType(instance, expectedType, msg)

Asserts that the instance is of the specified type.

Signature

public static void isInstanceOfType(Object instance, System.Type expectedType, String msg)

Parameters

  • instance: Type: Object Instance whose type you're checking.
  • expectedType: Type: System.Type Expected type.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the instance isn't of the specified type, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Account o = new Account();
Assert.isInstanceOfType(o, Account.class); // Succeeds

isInstanceOfType(instance, expectedType)

Asserts that the instance is of the specified type.

Signature

public static void isInstanceOfType(Object instance, System.Type expectedType)

Parameters

  • instance: Type: Object Instance whose type you're checking.
  • expectedType: Type: System.Type Expected type.

Return Value

Type: void

Usage

If the instance isn't of the specified type, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Account o = new Account();
Assert.isInstanceOfType(o, Account.class); // Succeeds
Account o = new Account();
Assert.isInstanceOfType(o, Account.class, 'Expected type.'); // Succeeds

isNotInstanceOfType(instance, notExpectedType, msg)

Asserts that the instance isn’t of the specified type.

Signature

public static void isNotInstanceOfType(Object instance, System.Type notExpectedType, String msg)

Parameters

  • instance: Type: Object Instance whose type you're checking.
  • notExpectedType: Type: System.Type Type that's not expected.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the instance is of the specified type, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Contact con = new Contact();
Assert.isNotInstanceOfType(con, Account.class, 'Not expected type'); // Succeeds

isNotInstanceOfType(instance, notExpectedType)

Asserts that the instance isn’t of the specified type.

Signature

public static void isNotInstanceOfType(Object instance, System.Type notExpectedType)

Parameters

  • instance: Type: Object Instance whose type you're checking.
  • notExpectedType: Type: System.Type Type that's not expected.

Return Value

Type: void

Usage

If the instance is of the specified type, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Contact con = new Contact();
Assert.isNotInstanceOfType(con, Account.class); // Succeeds

isNotNull(value, msg)

Asserts that the value isn’t null.

Signature

public static void isNotNull(Object value, String msg)

Parameters

  • value: Type: Object Value you’re checking to determine if it’s not null.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the value is null, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String myString = 'value'; 
Assert.isNotNull(myString, 'myString should not be null'); // Succeeds

isNotNull(value)

Asserts that the value isn’t null.

Signature

public static void isNotNull(Object value)

Parameters

  • value: Type: Object Value you’re checking to determine if it’s not null.

Return Value

Type: void

Usage

If the value is null, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String myString = 'value'; 
Assert.isNotNull(myString); // Succeeds

isNull(value, msg)

Asserts that the value is null.

Signature

public static void isNull(Object value, String msg)

Parameters

  • value: Type: Object Value you’re checking to determine if it’s null.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the value isn't null, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String myString = null; 
Assert.isNull(myString, 'String should be null'); // Succeeds

isNull(value)

Asserts that the value is null.

Signature

public static void isNull(Object value)

Parameters

  • value: Type: Object Value you’re checking to determine if it’s null.

Return Value

Type: void

Usage

If the value isn't null, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

String myString = null; 
Assert.isNull(myString); // Succeeds

isTrue(condition, msg)

Asserts that the specified condition is true.

Signature

public static void isTrue(Boolean condition, String msg)

Parameters

  • condition: Type: Boolean Condition you’re checking to determine if it’s true.
  • msg: Type: String (Optional) Custom message returned as part of the error message.

Return Value

Type: void

Usage

If the specified condition is false, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Boolean containsForce = 'Salesforce'.contains('force');
Assert.isTrue(containsForce, 'Contains force'); // Assertion succeeds

isTrue(condition)

Asserts that the specified condition is true.

Signature

public static void isTrue(Boolean condition)

Parameters

  • condition: Type: Boolean Condition you’re checking to determine if it’s true.

Return Value

Type: void

Usage

If the specified condition is false, a fatal error is returned that causes code execution to halt.

You can’t catch an assertion failure using a try/catch block even though it’s logged as an exception.

Example

Boolean containsForce = 'Salesforce'.contains('force');
Assert.isTrue(containsForce); // Assertion succeeds