Test-Driven iOS Development with Swift 4 - Third Edition

Important built-in assert functions

Each test needs to assert some expected behavior. The use of the XCTAssert functions tells Xcode what is expected.

A test method without a XCTAssert function will always pass as long as it compiles.

The most important assert functions are:

• XCTAssertTrue(_:_:file:line:): This asserts that an expression is true
• XCTAssertFalse(_:_:file:line:): This asserts that an expression is false
• XCTAssertEqual(_:_:_:file:line:): This asserts that two expressions are equal
• XCTAssertEqualWithAccuracy(_:_:accuracy:_:file:line:): This asserts that two expressions are the same, taking into account the accuracy defined in the accuracy parameter
• XCTAssertNotEqual(_:_:_:file:line:): This asserts that two expressions are not ...