Add SCALA_VERSION comment to test_coverage_*.sh

After @simuons asked about an apparently missing `--repo_env` setting in
`test_coverage_scalatest.sh` in bazel-contrib#1622, I realized the test case missing
it used `grep`, not `diff`. Rather than add the flag where it wasn't
needed, I commented the local `SCALA_VERSION` setting in each file.

Now that I think about it, the proper solution is to generate coverage
files for each Scala version, or for ranges of scala versions. Then we
can remove this `SCALA_VERSION` and `--repo_env` setting completely.
I'll look into that as a side quest.

Author: mbland

test/shell/test_coverage_equals_in_target.sh

@@ -4,6 +4,7 @@ dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 . "${dir}"/test_helper.sh
 runner=$(get_test_runner "${1:-local}")
 
+# Default to 2.12.19 for `diff` tests because other versions change the output.
 SCALA_VERSION="${SCALA_VERSION:-2.12.19}"
 
 test_coverage_target_name_contains_equals_sign() {

test/shell/test_coverage_scalatest.sh

@@ -4,6 +4,7 @@ dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 . "${dir}"/test_helper.sh
 runner=$(get_test_runner "${1:-local}")
 
+# Default to 2.12.19 for `diff` tests because other versions change the output.
 SCALA_VERSION="${SCALA_VERSION:-2.12.19}"
 
 test_coverage_on() {

test/shell/test_coverage_scalatest_resources.sh

@@ -4,6 +4,7 @@ dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 . "${dir}"/test_helper.sh
 runner=$(get_test_runner "${1:-local}")
 
+# Default to 2.12.19 for `diff` tests because other versions change the output.
 SCALA_VERSION="${SCALA_VERSION:-2.12.19}"
 
 test_coverage_succeeds_resource_call() {
@@ -16,7 +17,6 @@ test_coverage_succeeds_resource_call() {
 
 test_coverage_includes_resource_test_targets() {
     bazel coverage \
-        --repo_env="SCALA_VERSION=${SCALA_VERSION}" \
         --instrument_test_targets=True \
         //test/coverage_scalatest_resources/consumer:tests
     grep -q "SF:test/coverage_scalatest_resources/consumer/src/test/scala/com/example/consumer/ConsumerSpec.scala" $(bazel info bazel-testlogs)/test/coverage_scalatest_resources/consumer/tests/coverage.dat

test/shell/test_coverage_specs2_with_junit.sh

@@ -4,6 +4,7 @@ dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 . "${dir}"/test_helper.sh
 runner=$(get_test_runner "${1:-local}")
 
+# Default to 2.12.19 for `diff` tests because other versions change the output.
 SCALA_VERSION="${SCALA_VERSION:-2.12.19}"
 
 test_coverage_on() {
@@ -15,7 +16,6 @@ test_coverage_on() {
 
 test_coverage_includes_test_targets() {
     bazel coverage \
-        --repo_env="SCALA_VERSION=${SCALA_VERSION}" \
         --instrument_test_targets=True \
         //test/coverage_specs2_with_junit:test-specs2-with-junit
     grep -q "SF:test/coverage_specs2_with_junit/TestWithSpecs2WithJUnit.scala" $(bazel info bazel-testlogs)/test/coverage_specs2_with_junit/test-specs2-with-junit/coverage.dat