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Diffstat (limited to 'test/prism/desugar_compiler_test.rb')
| -rw-r--r-- | test/prism/desugar_compiler_test.rb | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/test/prism/desugar_compiler_test.rb b/test/prism/desugar_compiler_test.rb new file mode 100644 index 0000000000..1a1d580d2d --- /dev/null +++ b/test/prism/desugar_compiler_test.rb @@ -0,0 +1,80 @@ +# frozen_string_literal: true + +require_relative "test_helper" + +module Prism + class DesugarCompilerTest < TestCase + def test_and_write + assert_desugars("(AndNode (ClassVariableReadNode) (ClassVariableWriteNode (CallNode)))", "@@foo &&= bar") + assert_not_desugared("Foo::Bar &&= baz", "Desugaring would execute Foo twice or need temporary variables") + assert_desugars("(AndNode (ConstantReadNode) (ConstantWriteNode (CallNode)))", "Foo &&= bar") + assert_desugars("(AndNode (GlobalVariableReadNode) (GlobalVariableWriteNode (CallNode)))", "$foo &&= bar") + assert_desugars("(AndNode (InstanceVariableReadNode) (InstanceVariableWriteNode (CallNode)))", "@foo &&= bar") + assert_desugars("(AndNode (LocalVariableReadNode) (LocalVariableWriteNode (CallNode)))", "foo &&= bar") + assert_desugars("(AndNode (LocalVariableReadNode) (LocalVariableWriteNode (CallNode)))", "foo = 1; foo &&= bar") + end + + def test_or_write + assert_desugars("(IfNode (DefinedNode (ClassVariableReadNode)) (StatementsNode (ClassVariableReadNode)) (ElseNode (StatementsNode (ClassVariableWriteNode (CallNode)))))", "@@foo ||= bar") + assert_not_desugared("Foo::Bar ||= baz", "Desugaring would execute Foo twice or need temporary variables") + assert_desugars("(IfNode (DefinedNode (ConstantReadNode)) (StatementsNode (ConstantReadNode)) (ElseNode (StatementsNode (ConstantWriteNode (CallNode)))))", "Foo ||= bar") + assert_desugars("(IfNode (DefinedNode (GlobalVariableReadNode)) (StatementsNode (GlobalVariableReadNode)) (ElseNode (StatementsNode (GlobalVariableWriteNode (CallNode)))))", "$foo ||= bar") + assert_desugars("(OrNode (InstanceVariableReadNode) (InstanceVariableWriteNode (CallNode)))", "@foo ||= bar") + assert_desugars("(OrNode (LocalVariableReadNode) (LocalVariableWriteNode (CallNode)))", "foo ||= bar") + assert_desugars("(OrNode (LocalVariableReadNode) (LocalVariableWriteNode (CallNode)))", "foo = 1; foo ||= bar") + end + + def test_operator_write + assert_desugars("(ClassVariableWriteNode (CallNode (ClassVariableReadNode) (ArgumentsNode (CallNode))))", "@@foo += bar") + assert_not_desugared("Foo::Bar += baz", "Desugaring would execute Foo twice or need temporary variables") + assert_desugars("(ConstantWriteNode (CallNode (ConstantReadNode) (ArgumentsNode (CallNode))))", "Foo += bar") + assert_desugars("(GlobalVariableWriteNode (CallNode (GlobalVariableReadNode) (ArgumentsNode (CallNode))))", "$foo += bar") + assert_desugars("(InstanceVariableWriteNode (CallNode (InstanceVariableReadNode) (ArgumentsNode (CallNode))))", "@foo += bar") + assert_desugars("(LocalVariableWriteNode (CallNode (LocalVariableReadNode) (ArgumentsNode (CallNode))))", "foo += bar") + assert_desugars("(LocalVariableWriteNode (CallNode (LocalVariableReadNode) (ArgumentsNode (CallNode))))", "foo = 1; foo += bar") + end + + private + + def ast_inspect(node) + parts = [node.class.name.split("::").last] + + node.deconstruct_keys(nil).each do |_, value| + case value + when Node + parts << ast_inspect(value) + when Array + parts.concat(value.map { |element| ast_inspect(element) }) + end + end + + "(#{parts.join(" ")})" + end + + # Ensure every node is only present once in the AST. + # If the same node is present twice it would most likely indicate it is executed twice, which is invalid semantically. + # This also acts as a sanity check that Node#child_nodes returns only nodes or nil (which caught a couple bugs). + def ensure_every_node_once_in_ast(node, all_nodes = {}.compare_by_identity) + if all_nodes.include?(node) + raise "#{node.inspect} is present multiple times in the desugared AST and likely executed multiple times" + else + all_nodes[node] = true + end + node.child_nodes.each do |child| + ensure_every_node_once_in_ast(child, all_nodes) unless child.nil? + end + end + + def assert_desugars(expected, source) + ast = Prism.parse(source).value.accept(DesugarCompiler.new) + assert_equal expected, ast_inspect(ast.statements.body.last) + + ensure_every_node_once_in_ast(ast) + end + + def assert_not_desugared(source, reason) + ast = Prism.parse(source).value + assert_equal_nodes(ast, ast.accept(DesugarCompiler.new)) + end + end +end |