test: Mark the bom tests as slow.

test/bom.bats

@@ -9,6 +9,7 @@ function teardown() {
 }
 
 @test "all container contents must be accounted for" {
+  skip_slow_test
   cat > stacker.yaml <<EOF
 bom-parent:
     from:
@@ -66,6 +67,7 @@ EOF
 }
 
 @test "bom tool should work inside run" {
+  skip_slow_test
   cat > stacker.yaml <<EOF
 bom-parent:
     from:

test/convert.bats

@@ -48,9 +48,7 @@ EOF
 }
 
 @test "alpine" {
-  if [ -z "${SLOW_TEST}" ]; then
-    skip "test since slow tests are not enabled"
-  fi
+  skip_slow_test
   git clone https://github.com/alpinelinux/docker-alpine.git
   chmod -R a+rwx docker-alpine
   cd docker-alpine
@@ -65,9 +63,7 @@ EOF
 }
 
 @test "elasticsearch" {
-  if [ -z "${SLOW_TEST}" ]; then
-    skip "test since slow tests are not enabled"
-  fi
+  skip_slow_test
   git clone https://github.com/elastic/dockerfiles.git
   chmod -R a+rwx dockerfiles
   cd dockerfiles/elasticsearch
@@ -81,9 +77,7 @@ EOF
 }
 
 @test "python" {
-  if [ -z "${SLOW_TEST}" ]; then
-    skip "test since slow tests are not enabled"
-  fi
+  skip_slow_test
   git clone https://github.com/docker-library/python.git
   cd python/3.11/alpine3.17
   chmod -R a+rw .

test/helpers.bash

@@ -96,6 +96,16 @@ function require_privilege {
     [ "$PRIVILEGE_LEVEL" = "$1" ] || skip "test not valid for privilege level $PRIVILEGE_LEVEL"
 }
 
+function skip_slow_test {
+    case "${SLOW_TEST:-false}" in
+        true) return;;
+        false) skip "${BATS_TEST_NAME} is slow. Set SLOW_TEST=true to run.";;
+        *) stderr "SLOW_TEST variable must be 'true' or 'false'" \
+            "found '${SLOW_TEST}'"
+           return 1;;
+    esac
+}
+
 function tmpd() {
     mktemp -d "${PWD}/stackertest${1:+-$1}.XXXXXX"
 }