maven surefire plugin not finding Junit tests written in Scala - scala

Question

In a blank slate maven scala project, we're trying to get a Junit4 testcase identified up by maven surefire plugin. Where are we going wrong?
Inside src/test/scala/Main.scala we have:
import org.junit.Assert._
import org.junit.Test
class main {
#Test
def myTestCase {
assertTrue("#1 is greater than 0", 1>0)
}
}
Our POM is as follows.
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>groupId</groupId>
<artifactId>junitTestProject</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.0</version>
<dependencies>
<dependency>
<groupId>org.apache.maven.surefire</groupId>
<artifactId>surefire-junit47</artifactId>
<version>2.22.0</version>
</dependency>
</dependencies>
<configuration>
<includes>
<include>**/*.scala</include>
</includes>
</configuration>
</plugin>
</plugins>
</build>
</project>
Running maven test lifecycle within intelliJ, we get:
[INFO] --- maven-surefire-plugin:2.22.0:test (default-test) # junitTestProject ---
[INFO] No tests to run.
In case they were required, we tried experimenting also (probably incorrectly) with:
junit-interface
org.scalatestplus
junit-vintage-engine
Note: In an alternative project, we have tried with scalatest (and can get scalatest testcases identified by the scalatest-maven-plugin) but had project performance issues, so wanted to compare with just Junit & maven surefire