Warn when src/main or src/test is used in a glue or feature path

[mpkorstanje]

👓 What did you see?

Novice users often do not understand the difference between the classpath and the filesystem path.

For example this mistake often shows up on stack overflow:

@RunWith(Cucumber.class)
@CucumberOptions(
        features = "src/test/resources/features",
        glue = "src/test/java/com/example"
)

This should be

@RunWith(Cucumber.class)
@CucumberOptions(
        features = "classpath:features",
        glue = "com.example"
)

Here scr/main/java/com/example is a filesystem path while classpath:com/example a classpath path.

Due to misunderstanding the difference between these paths novice users often specify paths that are positively not glue paths.

Feature paths often just happen to work because unlike glue features don't have to be on the classpath.

Additionally while classpath uris are supported for glue paths the package name format is preferred to avoid confusion.

✅ What did you expect to see?

When passing any feature path starting with src/{test,main}/resources emit a warning that suggests replacing it with classpath: prefix.

Whe passing a glue path starts with src/{test,main}/{java,kotlin,scala,groovy} emit a warning that advices the use of the package name.

The warning should include the original path used and the suggested replacement.

For the feature path it should also include an explanation that mentions the possible ambiguity and advice the user to avoid it. Either by using the suggested replacement or moving the feature files away from well known filesystem paths that are put on the classpath.

For glue paths it should inform users that files in these paths are typically compiled by their build tool before the compiled files are put on the classpath when executing. As such they probably meant to use the package name.

🛠️ Implementation hints

Feature path parsing is implemented in FeaturePath. Checking for the prefix in parseAssumeFileScheme seems like the right place.

Glue paths are parsed in GluePath. The parseAssumeClasspathScheme seems like the right place.

Logging warnings should be done using Cucumbers logging utility. For example see:

cucumber-jvm/core/src/main/java/cucumber/api/cli/Main.java

Line 29 in 549fe86

log.warn(() -> "You are using deprecated Main class. Please use io.cucumber.core.cli.Main");

🧪 Testing hints

You can test log messages by adding a LogRecordListener to the LoggerFactory. See the surrounding code for more context:

cucumber-jvm/core/src/test/java/io/cucumber/core/runtime/FeaturePathFeatureSupplierTest.java

Lines 30 to 39 in 78adb8f

	@BeforeEach
	void setup() {
	logRecordListener = new LogRecordListener();
	LoggerFactory.addListener(logRecordListener);
	}
	@AfterEach
	void tearDown() {
	LoggerFactory.removeListener(logRecordListener);
	}

[tal66]

Hi, I started working on this issue :)

[mpkorstanje]

Awesome!

I've added some hints for testing. If you have any problems you can ask for help in the #commiters channel in slack. Link is in the read me.

[mpkorstanje]

@AlexBravo95 for questions please use stackoverflow. For bug reports, please create a new issue.