1 files changed, 132 insertions, 0 deletions
diff --git a/test/prism/pattern_test.rb b/test/prism/pattern_test.rb
new file mode 100644
index 0000000000..e0aa079cb9
--- /dev/null
+++ b/test/prism/pattern_test.rb
@@ -0,0 +1,132 @@
+# frozen_string_literal: true
+
+require_relative "test_helper"
+
+module Prism
+  class PatternTest < TestCase
+    def test_invalid_syntax
+      assert_raise(Pattern::CompilationError) { scan("", "<>") }
+    end
+
+    def test_invalid_constant
+      assert_raise(Pattern::CompilationError) { scan("", "Foo") }
+    end
+
+    def test_invalid_nested_constant
+      assert_raise(Pattern::CompilationError) { scan("", "Foo::Bar") }
+    end
+
+    def test_regexp_with_interpolation
+      assert_raise(Pattern::CompilationError) { scan("", "/\#{foo}/") }
+    end
+
+    def test_string_with_interpolation
+      assert_raise(Pattern::CompilationError) { scan("", '"#{foo}"') }
+    end
+
+    def test_symbol_with_interpolation
+      assert_raise(Pattern::CompilationError) { scan("", ":\"\#{foo}\"") }
+    end
+
+    def test_invalid_node
+      assert_raise(Pattern::CompilationError) { scan("", "IntegerNode[^foo]") }
+    end
+
+    def test_self
+      assert_raise(Pattern::CompilationError) { scan("", "self") }
+    end
+
+    def test_array_pattern_no_constant
+      results = scan("1 + 2", "[IntegerNode]")
+
+      assert_equal 1, results.length
+    end
+
+    def test_array_pattern
+      results = scan("1 + 2", "CallNode[name: :+, receiver: IntegerNode, arguments: [IntegerNode]]")
+
+      assert_equal 1, results.length
+    end
+
+    def test_alternation_pattern
+      results = scan("Foo + Bar + 1", "ConstantReadNode | IntegerNode")
+
+      assert_equal 3, results.length
+      assert_equal 1, results.grep(IntegerNode).first.value
+    end
+
+    def test_constant_read_node
+      results = scan("Foo + Bar + Baz", "ConstantReadNode")
+
+      assert_equal 3, results.length
+      assert_equal %w[Bar Baz Foo], results.map(&:slice).sort
+    end
+
+    def test_object_const
+      results = scan("1 + 2 + 3", "IntegerNode[]")
+
+      assert_equal 3, results.length
+    end
+
+    def test_constant_path
+      results = scan("Foo + Bar + Baz", "Prism::ConstantReadNode")
+
+      assert_equal 3, results.length
+    end
+
+    def test_hash_pattern_no_constant
+      results = scan("Foo + Bar + Baz", "{ name: :+ }")
+
+      assert_equal 2, results.length
+    end
+
+    def test_hash_pattern_regexp
+      results = scan("Foo + Bar + Baz", "{ name: /^[[:punct:]]$/ }")
+
+      assert_equal 2, results.length
+      assert_equal ["Prism::CallNode"], results.map { |node| node.class.name }.uniq
+    end
+
+    def test_nil
+      results = scan("foo", "{ receiver: nil }")
+
+      assert_equal 1, results.length
+    end
+
+    def test_regexp_options
+      results = scan("@foo + @bar + @baz", "InstanceVariableReadNode[name: /^@B/i]")
+
+      assert_equal 2, results.length
+    end
+
+    def test_string_empty
+      results = scan("", "''")
+
+      assert_empty results
+    end
+
+    def test_symbol_empty
+      results = scan("", ":''")
+
+      assert_empty results
+    end
+
+    def test_symbol_plain
+      results = scan("@foo", "{ name: :\"@foo\" }")
+
+      assert_equal 1, results.length
+    end
+
+    def test_symbol
+      results = scan("@foo", "{ name: :@foo }")
+
+      assert_equal 1, results.length
+    end
+
+    private
+
+    def scan(source, query)
+      Prism::Pattern.new(query).scan(Prism.parse(source).value).to_a
+    end
+  end
+end