1 files changed, 78 insertions, 0 deletions
diff --git a/spec/lib/gitlab/changelog/parser_spec.rb b/spec/lib/gitlab/changelog/parser_spec.rb
new file mode 100644
index 00000000000..1d353f5eb35
--- /dev/null
+++ b/spec/lib/gitlab/changelog/parser_spec.rb
@@ -0,0 +1,78 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Changelog::Parser do
+  let(:parser) { described_class.new }
+
+  describe '#root' do
+    it 'parses an empty template' do
+      expect(parser.root).to parse('')
+    end
+
+    it 'parses a variable with a single identifier step' do
+      expect(parser.root).to parse('{{foo}}')
+    end
+
+    it 'parses a variable with a single integer step' do
+      expect(parser.root).to parse('{{0}}')
+    end
+
+    it 'parses a variable with multiple selector steps' do
+      expect(parser.root).to parse('{{foo.bar}}')
+    end
+
+    it 'parses a variable with an integer selector step' do
+      expect(parser.root).to parse('{{foo.bar.0}}')
+    end
+
+    it 'parses the special "it" variable' do
+      expect(parser.root).to parse('{{it}}')
+    end
+
+    it 'parses a text node' do
+      expect(parser.root).to parse('foo')
+    end
+
+    it 'parses an if expression' do
+      expect(parser.root).to parse('{% if foo %}bar{% end %}')
+    end
+
+    it 'parses an if-else expression' do
+      expect(parser.root).to parse('{% if foo %}bar{% else %}baz{% end %}')
+    end
+
+    it 'parses an each expression' do
+      expect(parser.root).to parse('{% each foo %}foo{% end %}')
+    end
+
+    it 'parses an escaped newline' do
+      expect(parser.root).to parse("foo\\\nbar")
+    end
+
+    it 'parses a regular newline' do
+      expect(parser.root).to parse("foo\nbar")
+    end
+
+    it 'parses the default changelog template' do
+      expect(parser.root).to parse(Gitlab::Changelog::Config::DEFAULT_TEMPLATE)
+    end
+
+    it 'raises an error when parsing an integer selector that is too large' do
+      expect(parser.root).not_to parse('{{100000000000}}')
+    end
+  end
+
+  describe '#parse_and_transform' do
+    it 'parses and transforms a template' do
+      node = parser.parse_and_transform('foo')
+
+      expect(node).to be_instance_of(Gitlab::Changelog::AST::Expressions)
+    end
+
+    it 'raises parsing errors using a custom error class' do
+      expect { parser.parse_and_transform('{% each') }
+        .to raise_error(Gitlab::Changelog::Error)
+    end
+  end
+end