Support negative matches

This adds support for != and !~ operators
giving more flexibility in comparing values

3 files changed, 131 insertions, 0 deletions

diff --git a/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_equals_spec.rb b/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_equals_spec.rb
new file mode 100644
index 00000000000..9aa2f4efd67
--- /dev/null
+++ b/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_equals_spec.rb
@@ -0,0 +1,39 @@
+require 'spec_helper'
+
+describe Gitlab::Ci::Pipeline::Expression::Lexeme::NotEquals do
+  let(:left) { double('left') }
+  let(:right) { double('right') }
+
+  describe '.build' do
+    it 'creates a new instance of the token' do
+      expect(described_class.build('!=', left, right))
+        .to be_a(described_class)
+    end
+  end
+
+  describe '.type' do
+    it 'is an operator' do
+      expect(described_class.type).to eq :operator
+    end
+  end
+
+  describe '#evaluate' do
+    it 'returns true when left and right are not equal' do
+      allow(left).to receive(:evaluate).and_return(1)
+      allow(right).to receive(:evaluate).and_return(2)
+
+      operator = described_class.new(left, right)
+
+      expect(operator.evaluate(VARIABLE: 3)).to eq true
+    end
+
+    it 'returns false when left and right are equal' do
+      allow(left).to receive(:evaluate).and_return(1)
+      allow(right).to receive(:evaluate).and_return(1)
+
+      operator = described_class.new(left, right)
+
+      expect(operator.evaluate(VARIABLE: 3)).to eq false
+    end
+  end
+end
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
new file mode 100644
index 00000000000..fa3b9651fb4
--- /dev/null
+++ b/spec/lib/gitlab/ci/pipeline/expression/lexeme/not_matches_spec.rb
@@ -0,0 +1,80 @@
+require 'fast_spec_helper'
+require_dependency 're2'
+
+describe Gitlab::Ci::Pipeline::Expression::Lexeme::NotMatches do
+  let(:left) { double('left') }
+  let(:right) { double('right') }
+
+  describe '.build' do
+    it 'creates a new instance of the token' do
+      expect(described_class.build('!~', left, right))
+        .to be_a(described_class)
+    end
+  end
+
+  describe '.type' do
+    it 'is an operator' do
+      expect(described_class.type).to eq :operator
+    end
+  end
+
+  describe '#evaluate' do
+    it 'returns true when left and right do not match' do
+      allow(left).to receive(:evaluate).and_return('my-string')
+      allow(right).to receive(:evaluate)
+        .and_return(Gitlab::UntrustedRegexp.new('something'))
+
+      operator = described_class.new(left, right)
+
+      expect(operator.evaluate).to eq true
+    end
+
+    it 'returns false when left and right match' do
+      allow(left).to receive(:evaluate).and_return('my-awesome-string')
+      allow(right).to receive(:evaluate)
+        .and_return(Gitlab::UntrustedRegexp.new('awesome.string$'))
+
+      operator = described_class.new(left, right)
+
+      expect(operator.evaluate).to eq false
+    end
+
+    it 'supports matching against a nil value' do
+      allow(left).to receive(:evaluate).and_return(nil)
+      allow(right).to receive(:evaluate)
+        .and_return(Gitlab::UntrustedRegexp.new('pattern'))
+
+      operator = described_class.new(left, right)
+
+      expect(operator.evaluate).to eq true
+    end
+
+    it 'supports multiline strings' do
+      allow(left).to receive(:evaluate).and_return <<~TEXT
+        My awesome contents
+
+        My-text-string!
+      TEXT
+
+      allow(right).to receive(:evaluate)
+        .and_return(Gitlab::UntrustedRegexp.new('text-string'))
+
+      operator = described_class.new(left, right)
+
+      expect(operator.evaluate).to eq false
+    end
+
+    it 'supports regexp flags' do
+      allow(left).to receive(:evaluate).and_return <<~TEXT
+        My AWESOME content
+      TEXT
+
+      allow(right).to receive(:evaluate)
+        .and_return(Gitlab::UntrustedRegexp.new('(?i)awesome'))
+
+      operator = described_class.new(left, right)
+
+      expect(operator.evaluate).to eq false
+    end
+  end
+end
diff --git a/spec/lib/gitlab/ci/pipeline/expression/statement_spec.rb b/spec/lib/gitlab/ci/pipeline/expression/statement_spec.rb
index 11e73294f18..a9fd809409b 100644
--- a/spec/lib/gitlab/ci/pipeline/expression/statement_spec.rb
+++ b/spec/lib/gitlab/ci/pipeline/expression/statement_spec.rb
@@ -101,6 +101,18 @@ describe Gitlab::Ci::Pipeline::Expression::Statement do
       "$EMPTY_VARIABLE =~ /var.*/"         | false
       "$UNDEFINED_VARIABLE =~ /var.*/"     | false
       "$PRESENT_VARIABLE =~ /VAR.*/i"      | true
+      '$PRESENT_VARIABLE != "my variable"' | false
+      '"my variable" != $PRESENT_VARIABLE' | false
+      '$PRESENT_VARIABLE != null'          | true
+      '$EMPTY_VARIABLE != null'            | true
+      '"" != $EMPTY_VARIABLE'              | false
+      '$UNDEFINED_VARIABLE != null'        | false
+      'null != $UNDEFINED_VARIABLE'        | false
+      "$PRESENT_VARIABLE !~ /var.*e$/"     | false
+      "$PRESENT_VARIABLE !~ /^var.*/"      | true
+      "$EMPTY_VARIABLE !~ /var.*/"         | true
+      "$UNDEFINED_VARIABLE !~ /var.*/"     | true
+      "$PRESENT_VARIABLE !~ /VAR.*/i"      | false
     end
 
     with_them do