Pattern matching empty values follow Ruby behavior64383-pattern-matching-with-variables-causes-gitlabs-ci-lint-to-throw-500

Replace Array#any? and Array#none? with Array#present? and
Array#empty? so that arrays with nil elements count as matches.

Ruby behavior:

'' =~ // # => 0
'' !~ // # => false

Our operator with empty values:

regexp.scan(text.to_s) # => [nil]

4 files changed, 30 insertions, 2 deletions

diff --git a/lib/gitlab/ci/pipeline/expression/lexeme/matches.rb b/lib/gitlab/ci/pipeline/expression/lexeme/matches.rb
index c1088ae19fc..f7b0720d4a9 100644
--- a/lib/gitlab/ci/pipeline/expression/lexeme/matches.rb
+++ b/lib/gitlab/ci/pipeline/expression/lexeme/matches.rb
@@ -13,7 +13,7 @@ module Gitlab
               regexp = @right.evaluate(variables)
               return false unless regexp
 
-              regexp.scan(text.to_s).any?
+              regexp.scan(text.to_s).present?
             end
 
             def self.build(_value, behind, ahead)
diff --git a/lib/gitlab/ci/pipeline/expression/lexeme/not_matches.rb b/lib/gitlab/ci/pipeline/expression/lexeme/not_matches.rb
index 97dc4c7081a..02479ed28a4 100644
--- a/lib/gitlab/ci/pipeline/expression/lexeme/not_matches.rb
+++ b/lib/gitlab/ci/pipeline/expression/lexeme/not_matches.rb
@@ -13,7 +13,7 @@ module Gitlab
               regexp = @right.evaluate(variables)
               return true unless regexp
 
-              regexp.scan(text.to_s).none?
+              regexp.scan(text.to_s).empty?
             end
 
             def self.build(_value, behind, ahead)
diff --git a/spec/lib/gitlab/ci/pipeline/expression/lexeme/matches_spec.rb b/spec/lib/gitlab/ci/pipeline/expression/lexeme/matches_spec.rb
index d41b97742bf..a527783ffac 100644
--- a/spec/lib/gitlab/ci/pipeline/expression/lexeme/matches_spec.rb
+++ b/spec/lib/gitlab/ci/pipeline/expression/lexeme/matches_spec.rb
@@ -83,6 +83,20 @@ describe Gitlab::Ci::Pipeline::Expression::Lexeme::Matches do
       it { is_expected.to eq(false) }
     end
 
+    context 'when left is an empty string' do
+      let(:left_value)  { '' }
+      let(:right_value) { Gitlab::UntrustedRegexp.new('pattern') }
+
+      it { is_expected.to eq(false) }
+    end
+
+    context 'when left and right are empty strings' do
+      let(:left_value)  { '' }
+      let(:right_value) { Gitlab::UntrustedRegexp.new('') }
+
+      it { is_expected.to eq(true) }
+    end
+
     context 'when left is a multiline string and matches right' do
       let(:left_value) do
         <<~TEXT
diff --git a/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_matches_spec.rb b/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_matches_spec.rb
index 20bab73244a..fb4238ecaf3 100644
--- a/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_matches_spec.rb
+++ b/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_matches_spec.rb
@@ -83,6 +83,20 @@ describe Gitlab::Ci::Pipeline::Expression::Lexeme::NotMatches do
       it { is_expected.to eq(true) }
     end
 
+    context 'when left is an empty string' do
+      let(:left_value)  { '' }
+      let(:right_value) { Gitlab::UntrustedRegexp.new('pattern') }
+
+      it { is_expected.to eq(true) }
+    end
+
+    context 'when left and right are empty strings' do
+      let(:left_value)  { '' }
+      let(:right_value) { Gitlab::UntrustedRegexp.new('') }
+
+      it { is_expected.to eq(false) }
+    end
+
     context 'when left is a multiline string and matches right' do
       let(:left_value) do
         <<~TEXT