Merge pull request #184 from AaronC81/parser-errors-in-constants

Don't crash Sord if a constant value doesn't parse

Author: AaronC81

.github/workflows/examples.yml

@@ -19,4 +19,4 @@ jobs:
     - name: Run examples (RBI)
       run: bundle exec rake examples:seed[rbi]
     - name: Run examples (RBS)
-      run: bundle exec rake examples:seed[rbs]
+      run: bundle exec rake examples:reseed[rbs]

lib/sord/generator.rb

@@ -143,22 +143,29 @@ def add_constants(item)
         when :rbi
           # Parse so we can set up constant with correct heredoc syntax
           kwargs = {}
-          value_node = Parser::CurrentRuby.parse(constant.value)
-          loc = value_node.loc
-          if loc.instance_of? Parser::Source::Map::Heredoc
-            #
-            # heredocs in Ruby come after the full expression is complete.  e.g.,
-            # puts(>>FOO)
-            #   bar
-            # FOO
-            #
-            # so if we want to wrap them in a T.let, we need to parse out the expression vs the rest
-            kwargs[:heredocs] = constant.value[loc.heredoc_body.begin_pos...loc.heredoc_end.end_pos]
-            expression = loc.expression
-            value = constant.value[expression.begin_pos...expression.end_pos]
-          else
-            value = constant.value
+
+          value = constant.value
+          begin
+            value_node = Parser::CurrentRuby.parse(constant.value)
+            loc = value_node.loc
+            if loc.instance_of? Parser::Source::Map::Heredoc
+              #
+              # heredocs in Ruby come after the full expression is complete.  e.g.,
+              # puts(>>FOO)
+              #   bar
+              # FOO
+              #
+              # so if we want to wrap them in a T.let, we need to parse out the expression vs the rest
+              kwargs[:heredocs] = constant.value[loc.heredoc_body.begin_pos...loc.heredoc_end.end_pos]
+              expression = loc.expression
+              value = constant.value[expression.begin_pos...expression.end_pos]
+            end
+
+          rescue Parser::SyntaxError => e
+            # Emit a warning, since this may cause a syntax error when parsing the RBI
+            Logging.warn("syntax error on constant value: #{e}", constant)
           end
+
           @current_object.create_constant(constant_name, value: "T.let(#{value}, T.untyped)", **kwargs) do |c|
             c.add_comments(constant.docstring.all.split("\n"))
           end

spec/generator_spec.rb

@@ -1151,6 +1151,32 @@ class A
     RUBY
   end
 
+  it 'gracefully handles malformed expressions as constants' do
+    # This isn't something we expect to happen very often, but we at least want to know Sord itself
+    # doesn't blow up.
+    
+    # This string is valid Ruby syntax, but `parser` rejects it intentionally
+    # See https://github.com/whitequark/parser/issues/283
+    YARD.parse_string(<<-RUBY)
+      class A
+        MALFORMED = "\\xFF"
+      end
+    RUBY
+
+    expect(rbi_gen.generate.strip).to eq fix_heredoc(<<-RUBY)
+      # typed: strong
+      class A
+        MALFORMED = T.let("\\xFF", T.untyped)
+      end
+    RUBY
+
+    expect(rbs_gen.generate.strip).to eq fix_heredoc(<<-RUBY)
+      class A
+        MALFORMED: untyped
+      end
+    RUBY
+  end
+
   it 'does not generate constants from included classes' do
     YARD.parse_string(<<-RUBY)
       class A