@CsvFileSource for external CSV in JUnit - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @CsvFileSource annotation in JUnit?

It is used to provide external CSV files as a source of parameters for parameterized tests, allowing multiple test cases to run with different input data.

beginner

How do you specify the path to an external CSV file using @CsvFileSource?

You use the resources folder and provide the relative path in the resources attribute, for example: @CsvFileSource(resources = "/data/test-data.csv").

intermediate

What happens if the CSV file specified in @CsvFileSource is missing or the path is incorrect?

The test will fail to run and throw an error indicating that the resource could not be found, so it is important to verify the file path and that the file is included in the test resources.

intermediate

Can @CsvFileSource handle CSV files with headers?

Yes, but you need to skip the header row by setting numLinesToSkip = 1 in the annotation to avoid treating the header as test data.

beginner

Write a simple example of a JUnit 5 parameterized test using @CsvFileSource with an external CSV file.

@ParameterizedTest @CsvFileSource(resources = "/data/input.csv", numLinesToSkip = 1) void testWithCsvFileSource(String input, int expected) { assertNotNull(input); assertTrue(expected >= 0); }

What attribute do you use to specify the CSV file path in @CsvFileSource?

A resources

B files

C path

D location

The correct attribute to specify the CSV file path is resources.

How do you skip the header row in a CSV file when using @CsvFileSource?

A Set <code>skipHeader=true</code>

B Remove the header manually

C Set <code>numLinesToSkip=1</code>

D Use <code>ignoreHeader=true</code>

You skip the header row by setting numLinesToSkip=1 in the annotation.

If the CSV file is not found, what happens when running a test with @CsvFileSource?

A Test passes automatically

B Test is skipped silently

C Test runs with empty data

D Test fails with an error

The test fails with an error indicating the resource could not be found.

Which JUnit feature does @CsvFileSource support?

A Parameterized tests

B Test suites

C Mocking objects

D Test lifecycle callbacks

@CsvFileSource is used for parameterized tests to run the same test with different inputs.

Where should the CSV file be placed to be accessible by @CsvFileSource?

A Inside the <code>src/main/java</code> folder

B Inside the <code>src/test/resources</code> folder

C In the root project folder

D Anywhere on the computer

CSV files should be placed in src/test/resources so they are available on the test classpath.

Explain how to use @CsvFileSource to run a parameterized test with data from an external CSV file.

Think about how JUnit reads CSV files and passes data to test methods.

Describe common errors when using @CsvFileSource and how to fix them.

Consider file location and data format issues.