1 files changed, 134 insertions, 0 deletions
diff --git a/test/prism/heredoc_dedent_test.rb b/test/prism/heredoc_dedent_test.rb
new file mode 100644
index 0000000000..4e7a3c0a14
--- /dev/null
+++ b/test/prism/heredoc_dedent_test.rb
@@ -0,0 +1,134 @@
+# frozen_string_literal: true
+
+require_relative "test_helper"
+
+module Prism
+  class HeredocDedentTest < TestCase
+    def test_content_dedented_interpolation_content
+      assert_heredoc_dedent(
+        "  a\n" "1\n" "  a\n",
+        "<<~EOF\n" "  a\n" "\#{1}\n" "  a\n" "EOF\n"
+      )
+    end
+
+    def test_content
+      assert_heredoc_dedent(
+        "a\n",
+        "<<~EOF\n" "  a\n" "EOF\n"
+      )
+    end
+
+    def test_tabs_dedent_spaces
+      assert_heredoc_dedent(
+        "\ta\n" "b\n" "\t\tc\n",
+        "<<~EOF\n" "\ta\n" "  b\n" "\t\tc\n" "EOF\n"
+      )
+    end
+
+    def test_interpolation_then_content
+      assert_heredoc_dedent(
+        "1 a\n",
+        "<<~EOF\n" "  \#{1} a\n" "EOF\n"
+      )
+    end
+
+    def test_content_then_interpolation
+      assert_heredoc_dedent(
+        "a 1\n",
+        "<<~EOF\n" "  a \#{1}\n" "EOF\n"
+      )
+    end
+
+    def test_content_dedented_interpolation
+      assert_heredoc_dedent(
+        " a\n" "1\n",
+        "<<~EOF\n" "  a\n" " \#{1}\n" "EOF\n"
+      )
+    end
+
+    def test_content_interpolation
+      assert_heredoc_dedent(
+        "a\n" "1\n",
+        "<<~EOF\n" "  a\n" "  \#{1}\n" "EOF\n"
+      )
+    end
+
+    def test_content_content
+      assert_heredoc_dedent(
+        "a\n" "b\n",
+        "<<~EOF\n" "  a\n" "  b\n" "EOF\n"
+      )
+    end
+
+    def test_content_indented_content
+      assert_heredoc_dedent(
+        "a\n" "  b\n",
+        "<<~EOF\n" "  a\n" "    b\n" "EOF\n"
+      )
+    end
+
+    def test_content_dedented_content
+      assert_heredoc_dedent(
+        "\ta\n" "b\n",
+        "<<~EOF\n" "\t\t\ta\n" "\t\tb\n" "EOF\n"
+      )
+    end
+
+    def test_single_quote
+      assert_heredoc_dedent(
+        "a \#{1}\n",
+        "<<~'EOF'\n" "a \#{1}\n" "EOF\n"
+      )
+    end
+
+    def test_mixed_indentation
+      assert_heredoc_dedent(
+        "a\n" " b\n",
+        "<<~EOF\n" "\ta\n" "\t b\n" "EOF\n"
+      )
+    end
+
+    def test_indented_content_content
+      assert_heredoc_dedent(
+        " a\n" "b\n",
+        "<<~EOF\n" "\t a\n" "\tb\n" "EOF\n"
+      )
+    end
+
+    def test_indent_size
+      assert_heredoc_dedent(
+        "a\n" "  b\n",
+        "<<~EOF\n" "\ta\n" "          b\n" "EOF\n"
+      )
+    end
+
+    def test_blank_lines
+      assert_heredoc_dedent(
+        "a\n" "\n" "b\n",
+        "<<~EOF\n" "  a\n" "\n" "  b\n" "EOF\n"
+      )
+    end
+
+    def test_many_blank_lines
+      assert_heredoc_dedent(
+        "a\n" "\n" "\n" "\n" "\n" "b\n",
+        "<<~EOF\n" "  a\n" "\n" "\n" "\n" "\n" "  b\n" "EOF\n"
+      )
+    end
+
+    private
+
+    def assert_heredoc_dedent(expected, source)
+      node = Prism.parse_statement(source)
+
+      if node.is_a?(StringNode)
+        actual = node.unescaped
+      else
+        actual = node.parts.map { |part| part.is_a?(StringNode) ? part.unescaped : "1" }.join
+      end
+
+      assert_equal(expected, actual)
+      assert_equal(eval(source), actual)
+    end
+  end
+end