Intellij runner on multi module project

This project setup show some issues I encountered with the Intellij IDEA runner. All the issues described here are present on the Intellij 2021.3.1 release (Build #IC-213.6461.79, built on December 28, 2021).

Project context

The project rely on code generation (Dagger2).
It is composed of 4 modules:

• android (a simple android module used here to trigger the intellij android plugin)
• core (which contains a class that can print the current project version)
• game (a java module which relies on core to create a jar that print the current project version)
• chat (a kotlin module which relies on core to create a jar that print the current project version)

When running the game and chat main classes using the gradle runner, everything works fine as expected (classes are generated, compiled, resources are processed and gathered into the classpath).
However, my real project have 5 launch configurations and launching them all at the same time using a compound can take up to 3 minutes using Gradle when it is about 10 seconds using the Intellij IDEA runner.

Unfortunately, when I switch to the Intellij IDEA runner a couple of odd things start appearing.
I understand that the IDEA runner do miss some gradle feature and I am fine with that but its build actions are inconsistents thus it does not allow me to have a nice workaround.

Below I described 4 test cases that summarize the issues encountered.

Case 1

Given

• android plugin enabled
• android.tasks.runner.restricted set to true (This option is available via the Intellij registry panel)
• Run/Debug option set to Intellij IDEA

When

• Launching the main class from the game module (Java module)

Then

Build

• Does not perform any gradle tasks
• Generates the dagger classes (.java) directly into the module in the module under src/main/generated
• Compiles the classes into the build/classes/java/main folder
• Does not copy the module resources into the default Intellij out build folder nor into the gradle build folder

Editor

• Does see the generated dagger classes from the src/main/generated folder

Run execution

• Includes the build/classes/java/main folder in the classpath for running the app
• It does not include the build/resources/main folder in the classpath for running the app
• However, if an out/production/resources folder is present when the main is launched, it adds it into the classpath as well

Questions

• Why Intellij do not copy the module resources folder into the out folder automatically?

Case 2

Given

• android plugin enabled
• android.tasks.runner.restricted set to true (This option is available via the Intellij registry panel)
• Run/Debug option set to Intellij IDEA

When

• Launching the main class from the chat module (Kotlin module)

Then

Build

• Does not perform any gradle tasks
• Does not generate any dagger classes (thus creating compilations errors)

If I manually generate the dagger classes file using gradle kaptKotlin task, it also:

• Compiles all classes into the build/classes/java/main folder
• Does not copy the module resources into the default Intellij out build folder nor into the gradle build folder

Editor

• Does see the generated dagger classes from the build/generated/source/kapt/main folder

Run execution

• Includes the build/classes/java/main folder in the classpath for running the app
• Includes the build/tmp/kapt3/classes/main folder in the classpath for running the app (empty folder)
• It does not include the build/resources/main folder in the classpath for running the app
• However, if an out/production/resources folder is present when the main is launched, it adds it into the classpath as well

Questions

• Why Intellij do not generate the kotlin dagger classes?
• Why Intellij do not copy the module resources folder into the out folder automatically?
• Is it expected that Intellij copy the Kotlin classes into the build/classes/java/main instead of build/classes/kotlin/main?
• Why the folder build\tmp\kapt3\classes\main is added to the classpath?

Notes

The cases 3&4 are the same as 1&2 with the android.task.runner.restricted set to false
The behaviors are much different.

Case 3

Given

• android plugin enabled
• android.tasks.runner.restricted set to false (This option is available via the Intellij registry panel)
• Run/Debug option set to Intellij IDEA

When

• Launching the main class from the game module (Java module)

Then

Build

• Generate the dagger classes (.java) directly into the build/generated/sources/annotationProcessor/java/main folder
• Trigger gradle compileJava, and testClasses tasks (which triggers the processResources task as well)
• Compile the classes into the "build/classes/java/main" folder
• Does not copy the module resources into the default Intellij out build folder

Editor

• Does not see the generated dagger classes from the build/generated/sources/annotationProcessor/java/main folder

Run execution

• Include the build/classes/java/main folder in the classpath for running the app
• It does not include the build/resources/main folder in the classpath for running the app
• However, if an out/production/resources folder is present when the main is launched, it adds it into the classpath as well

Questions

I assume in this case the gradle tasks are run because of the android plugin runner and it should not be the case. Why Intellij does not copy the module resources into the out folder? Why intellij does not use the build/resources/main folder into the classpath to run the app? Why the editor does not see the generated dagger classes from the build/generated/sources/annotationProcessor/java/main folder?

Case 4

Given

• android plugin enabled
• android.tasks.runner.restricted set to false (This option is available via the Intellij registry panel)
• Run/Debug option set to Intellij IDEA

When

• Launching the main class from the chat module (Kotlin module)

Then

Build

• Generate the dagger classes (.java) directly into the build/generated/source/kapt/main folder
• Trigger gradle compileJava, and testClasses tasks (which triggers the processResources task as well)
• It compile the java classes (dagger generated) into the build/classes/java/main folder It compile the kotlin classes (module classes) into the build/classes/kotlin/main folder
• Does not copy the module resources into the default Intellij out build folder

Editor

• Does see the generated dagger classes from the build/generated/source/kapt/main folder

Run execution

• Include the build/classes/java/main folder in the classpath for running the app
• It does not include the build/resources/main folder in the classpath for running the app
• It does not include the build/classes/kotlin/main folder in the classpath for running the app (thus making the app fail)
• However, if an out/production/resources folder is present when the main is launched, it adds it into the classpath as well

Questions

I assume in this case the gradle task are run because of the android plugin runner and it should not be the case. Why Intellij does not copy the module resources into the out folder? Why intellij does not use the build/resources/main folder into the classpath to run the app? Why intellij does not include the build/classes/kotlin/main folder in the classpath for running the app