Fix 500 error in CI lint when included templates are an arraysh-fix-ci-lint-500-error

Previously the following syntax would fail in the linter with an
error 500:

```
include:
  template:
    - License-Management.gitlab-ci.yml
    - Dependency-Scanning.gitlab-ci.yml
    - SAST.gitlab-ci.yml
```

Now the error will call out specifically that the value
is not a string.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/66605

1 files changed, 6 insertions, 0 deletions

diff --git a/spec/lib/gitlab/ci/config/external/file/base_spec.rb b/spec/lib/gitlab/ci/config/external/file/base_spec.rb
index dd536a241bd..af995f4869a 100644
--- a/spec/lib/gitlab/ci/config/external/file/base_spec.rb
+++ b/spec/lib/gitlab/ci/config/external/file/base_spec.rb
@@ -41,6 +41,12 @@ describe Gitlab::Ci::Config::External::File::Base do
   end
 
   describe '#valid?' do
+    context 'when location is not a string' do
+      let(:location) { %w(some/file.txt other/file.txt) }
+
+      it { is_expected.not_to be_valid }
+    end
+
     context 'when location is not a YAML file' do
       let(:location) { 'some/file.txt' }