Update documentation on running single scenarios with Gradle

Author: mpkorstanje

Diff for: README.md

@@ -56,12 +56,8 @@ For available parameters see: `io.cucumber.junit.platform.engine.Constants`
 
 ## Run a subset of Features or Scenarios
 
-Specify a particular scenario by *line*
-
-    @SelectClasspathResource(value = "io/cucumber/skeleton/belly.feature", line = 3)
-
-In case you have multiple feature files or scenarios to run against repeat the
-annotation.
+### By Tag
+#### With the JUnit Suite Engine
 
 You can also specify what to run by *tag*. 
 
@@ -80,31 +76,68 @@ Then add an annotation to `RunCucumberTest`.
 @IncludeTags("Zucchini")
 ```
 
+#### With Maven
+
 When using Maven, tags can be selected from the CLI using the `groups` and `excludedGroups` parameters. These take a
 [JUnit5 Tag Expression](https://junit.org/junit5/docs/current/user-guide/#running-tests-tag-expressions). 
 Note: When using JUnit, the `@` is not part of the tag.
 
-```
+```shell
 mvn verify -DexcludedGroups="Haricots" -Dgroups="Zucchini | Gherkin"
 ```
 
-### Running a single scenario or feature
+#### With Gradle
+
+When using Gradle, tags can be selected through the [build configuration](https://docs.gradle.org/current/userguide/java_testing.html#test_grouping). These take a [JUnit5 Tag Expression](https://junit.org/junit5/docs/current/user-guide/#running-tests-tag-expressions).
+Note: When using JUnit, the `@` is not part of the tag.
+
+```kotlin
+tasks.withType<Test>().configureEach {
+    useJUnitPlatform {
+        includeTags("Zucchini | Gherkin")
+        excludeTags("Haricots")
+    }
+}
+```
+
+### By line
+
+#### With the JUnit Suite Engine
+
+Specify a particular scenario by *line*
 
-Maven and Gradle do not (yet) support selecting single features or scenarios
+    @SelectClasspathResource(value = "io/cucumber/skeleton/belly.feature", line = 3)
+
+In case you have multiple feature files or scenarios to run against repeat the
+annotation.
+
+#### With Maven
+
+Maven does not (yet) support selecting single features or scenarios
 with JUnit selectors. As a work around the `cucumber.features` property can be
 used. Because this property will cause Cucumber to ignore any other selectors
 from JUnit it is prudent to only execute the Cucumber engine.
 
-#### With Maven
-
 To select the scenario on line 3 of the `belly.feature` file use:
 
-```
+```shell
 ./mvnw test -Dsurefire.includeJUnit5Engines=cucumber -Dcucumber.features=src/test/resources/io/cucumber/skeleton/belly.feature:3 
 ```
 
 Note: Add `-Dcucumber.plugin=pretty` to get a more detailed output during test execution.
 
 #### With Gradle
 
-TODO: (I don't know how to do this. Feel free to send a pull request. ;))
+Gradle does not (yet) support selecting single features or scenarios
+with JUnit selectors. As a work around the `cucumber.features` property can be
+used. Because this property will cause Cucumber to ignore any other selectors
+from JUnit it is prudent to only execute the Cucumber engine.
+
+```shell
+./gradlew test --rerun-tasks --info -Dcucumber.features=src/test/resources/io/cucumber/skeleton/belly.feature:3
+```
+
+Note: Add `-Dcucumber.plugin=pretty` to get a more detailed output during test execution.
+Note: Because both the Suite Engine and the Cucumber Engine are included, this
+      will run tests twice. (If you know how to prevent this, please send a pull
+      request).

Diff for: gradle/build.gradle.kts

@@ -20,6 +20,13 @@ repositories {
 
 tasks.withType<Test> {
     useJUnitPlatform()
+
+    // Pass selected system properties to Cucumber
+    systemProperty("cucumber.features", System.getProperty("cucumber.features"))
+    systemProperty("cucumber.filter.tags", System.getProperty("cucumber.filter.tags"))
+    systemProperty("cucumber.filter.name", System.getProperty("cucumber.filter.name"))
+    systemProperty("cucumber.plugin", System.getProperty("cucumber.plugin"))
+
     // Work around. Gradle does not include enough information to disambiguate
     // between different examples and scenarios.
     systemProperty("cucumber.junit-platform.naming-strategy", "long")

Diff for: gradle/src/test/java/io/cucumber/skeleton/RunCucumberTest.java

@@ -6,12 +6,10 @@
 import org.junit.platform.suite.api.Suite;
 
 import static io.cucumber.junit.platform.engine.Constants.PLUGIN_PROPERTY_NAME;
-import static io.cucumber.junit.platform.engine.Constants.GLUE_PROPERTY_NAME;
 
 @Suite
 @IncludeEngines("cucumber")
 @SelectPackages("io.cucumber.skeleton")
 @ConfigurationParameter(key = PLUGIN_PROPERTY_NAME, value = "pretty")
-@ConfigurationParameter(key = GLUE_PROPERTY_NAME, value = "io.cucumber.skeleton")
 public class RunCucumberTest {
 }

Diff for: gradle/src/test/resources/junit-platform.properties

@@ -1,2 +1,2 @@
-# Change this to false to display the Cucumber Reports banner
-cucumber.publish.quiet=true
+# Cucumber searches this package for your step definitions, ect
+cucumber.glue=io.cucumber.skeleton

Diff for: maven/src/test/java/io/cucumber/skeleton/RunCucumberTest.java

@@ -5,13 +5,11 @@
 import org.junit.platform.suite.api.SelectPackages;
 import org.junit.platform.suite.api.Suite;
 
-import static io.cucumber.junit.platform.engine.Constants.PLUGIN_PROPERTY_NAME;
 import static io.cucumber.junit.platform.engine.Constants.GLUE_PROPERTY_NAME;
 
 @Suite
 @IncludeEngines("cucumber")
 @SelectPackages("io.cucumber.skeleton")
-@ConfigurationParameter(key = PLUGIN_PROPERTY_NAME, value = "pretty")
 @ConfigurationParameter(key = GLUE_PROPERTY_NAME, value = "io.cucumber.skeleton")
 public class RunCucumberTest {
 }

Diff for: maven/src/test/resources/junit-platform.properties

@@ -1,2 +1,2 @@
-# Change this to false to display the Cucumber Reports banner
-cucumber.publish.quiet=true
+# Cucumber searches this package for your step definitions, ect
+cucumber.glue=io.cucumber.skeleton