test: cleaner helper file

test/builder_amazon_ebs.bats

@@ -8,9 +8,7 @@ load test_helper
 fixtures amazon-ebs
 
 teardown() {
-    aws ec2 describe-images --owners self --output json --filters 'Name=tag:packer-test,Values=true' \
-        | jq -r -M '.Images[]["ImageId"]' \
-        | xargs -n1 aws ec2 deregister-image --image-id
+    aws_ami_cleanup
 }
 
 @test "build minimal.json" {

test/test_helper.bash

@@ -7,12 +7,9 @@ for cmd in "${required[@]}"; do
     }
 done
 
-# This sets the directory for fixtures by specifying the name of
-# the folder with fixtures.
-fixtures() {
-    FIXTURE_ROOT="$BATS_TEST_DIRNAME/fixtures/$1"
-}
-
+#--------------------------------------------------------------------
+# Bats modification
+#--------------------------------------------------------------------
 # This allows us to override a function in Bash
 save_function() {
     local ORIG_FUNC=$(declare -f $1)
@@ -30,3 +27,19 @@ run() {
         echo $line
     done
 }
+
+#--------------------------------------------------------------------
+# Helper functions
+#--------------------------------------------------------------------
+# This sets the directory for fixtures by specifying the name of
+# the folder with fixtures.
+fixtures() {
+    FIXTURE_ROOT="$BATS_TEST_DIRNAME/fixtures/$1"
+}
+
+# This deletes any AMIs with a tag "packer-test" of "true"
+aws_ami_cleanup() {
+    aws ec2 describe-images --owners self --output json --filters 'Name=tag:packer-test,Values=true' \
+        | jq -r -M '.Images[]["ImageId"]' \
+        | xargs -n1 aws ec2 deregister-image --image-id
+}