assertEqualsJvmFileReference

Checks that a string matches a file in src/jvmTest/resources. When environment variable UPDATE_TEST_REF=true, instead of checking, this functions updates the file with the expected content.

This is similar to jest's snapshot testing: https://jestjs.io/docs/snapshot-testing

To simplify its usage, it is recommended to define a jvmTestFix gradle task as follows:

Use ./gradlew jvmTestFix to update these files

jvmTestFix gradle task should add environment("UPDATE_TEST_REF", "true")

val jvmTestFix = tasks.create("jvmTestFix", Test::class) {
    group = "verification"
    environment("UPDATE_TEST_REF", "true")
    testClassesDirs = jvmTest.testClassesDirs
    classpath = jvmTest.classpath
    bootstrapClasspath = jvmTest.bootstrapClasspath
    systemProperty("java.awt.headless", "true")
}