Add unit test to the function that determines which regions are appli…

…cable.

Signed-off-by: Vasil Sirakov <sirakov97@gmail.com>

providers/aws/resources/aws_ec2_test.go

@@ -76,3 +76,35 @@ func TestShouldExcludeInstance(t *testing.T) {
  require.False(t, shouldExcludeInstance(instance, filters))
  })
 }
+
+func TestDetermineApplicableRegions(t *testing.T) {
+ t.Run("allow regions override initial region list", func(t *testing.T) {
+ initialRegions := []string{"a", "b"}
+ allowedRegions := []string{"b", "c"}
+ excludedRegions := []string{}
+
+ expected := []string{"b", "c"}
+ actual := determineApplicableRegions(initialRegions, allowedRegions, excludedRegions)
+ require.ElementsMatch(t, expected, actual)
+ })
+
+ t.Run("excluded regions work correctly", func(t *testing.T) {
+ initialRegions := []string{"a", "b"}
+ allowedRegions := []string{}
+ excludedRegions := []string{"b"}
+
+ expected := []string{"a"}
+ actual := determineApplicableRegions(initialRegions, allowedRegions, excludedRegions)
+ require.ElementsMatch(t, expected, actual)
+ })
+
+ t.Run("excluded regions not present in the initial slice are ignored", func(t *testing.T) {
+ initialRegions := []string{"a", "b"}
+ allowedRegions := []string{}
+ excludedRegions := []string{"b", "c", "d", "e"}
+
+ expected := []string{"a"}
+ actual := determineApplicableRegions(initialRegions, allowedRegions, excludedRegions)
+ require.ElementsMatch(t, expected, actual)
+ })
+}