Fix #319

CHANGELOG.md

@@ -7,9 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 
 ### Fixed
+- Fix error when formatting ERB ([#319](https://github.com/ruby-formatter/rufo/issues/319))
 
 ### Changed
-
 - Dropped support for Ruby 2.7 as it is end of life.
 
 ### Added

lib/rufo/formatter.rb

@@ -18,6 +18,7 @@ def initialize(code, **options)
 
     @tokens = Rufo::Parser.lex(code).reverse!
     @sexp = Rufo::Parser.sexp(code)
+    @sexp ||= Rufo::Parser.sexp_unparsable_code(code)
 
     # sexp being nil means that the code is not valid.
     # Parse the code so we get better error messages.

lib/rufo/parser.rb

@@ -10,4 +10,48 @@ def compile_error(msg)
   def on_parse_error(msg)
     raise ::Rufo::SyntaxError.new(msg, lineno)
   end
+
+  def self.sexp_unparsable_code(code)
+    code_type = detect_unparsable_code_type(code)
+
+    case code_type
+    when :yield
+      extract_original_code_sexp(
+        "def __rufo_dummy; #{code}; end",
+        ->(exp) { exp => [:def, *, [:bodystmt, exps, *]]; exps }
+      )
+    when :next, :break, :redo
+      extract_original_code_sexp(
+        "loop do; #{code}; end",
+        ->(exp) { exp => [:method_add_block, *, [:do_block, nil, [:bodystmt, [[:void_stmt], *exps], *]]]; exps }
+      )
+    when :retry
+      extract_original_code_sexp(
+        "begin; rescue; #{code}; end",
+        ->(exp) { exp => [:begin, [:bodystmt, Array, [:rescue, nil, nil, exps, *], *]]; exps }
+      )
+    end
+  end
+
+  def self.detect_unparsable_code_type(code)
+    tokens = self.lex(code)
+    token = tokens.find { |_, kind| kind != :on_sp && kind != :on_ignored_nl }
+
+    case token
+    in [_, :on_kw, "yield" | "next" | "break" | "retry" | "redo" => kw, _]
+      kw.to_sym
+    else
+      nil
+    end
+  end
+
+  def self.extract_original_code_sexp(decorated_code, extractor)
+    sexp = self.sexp(decorated_code)
+    return nil unless sexp
+
+    # [:program, [exp]]
+    exp = sexp[1][0]
+    code_exps = extractor.call(exp)
+    [:program, code_exps]
+  end
 end

spec/lib/rufo/erb_formatter_spec.rb

@@ -84,5 +84,10 @@
       result = subject.format("<% a(nil) { %>\nabc\n<% } %>")
       expect(result).to eql("<% a(nil) { %>\nabc\n<% } %>")
     end
+
+    it "formats standalone 'yield'" do
+      result = subject.format("<%=yield%>")
+      expect(result).to eql("<%= yield %>")
+    end
   end
 end

spec/lib/rufo/formatter_source_specs/break.rb.spec

@@ -1,44 +1,29 @@
 #~# ORIGINAL break
-loop do
 
 break
-end
 
 #~# EXPECTED
-loop do
-  break
-end
+break
 
 #~# ORIGINAL
-loop do
 
 break  1
-end
 
 #~# EXPECTED
-loop do
-  break 1
-end
+break 1
 
 #~# ORIGINAL
-loop do
+
 break  1 , 2
-end
 
 #~# EXPECTED
-loop do
-  break 1, 2
-end
+break 1, 2
 
 #~# ORIGINAL
-loop do
 
 break  1 ,
  2
-end
 
 #~# EXPECTED
-loop do
-  break 1,
-        2
-end
+break 1,
+      2

spec/lib/rufo/formatter_source_specs/next.rb.spec

@@ -1,46 +1,29 @@
 #~# ORIGINAL next
-loop do
 
 next
-end
 
 #~# EXPECTED
-loop do
-  next
-end
+next
 
 #~# ORIGINAL
-loop do
 
 next  1
-end
 
 #~# EXPECTED
-loop do
-  next 1
-end
+next 1
 
 #~# ORIGINAL
-loop do
 
 next  1 , 2
-end
 
 #~# EXPECTED
-loop do
-  next 1, 2
-end
+next 1, 2
 
 #~# ORIGINAL
-loop do
 
 next  1 ,
  2
-end
 
 #~# EXPECTED
-loop do
-  next 1,
-       2
-end
-
+next 1,
+     2

spec/lib/rufo/formatter_source_specs/redo.rb.spec

@@ -1,10 +1,6 @@
 #~# ORIGINAL redo
-loop do
 
 redo
-end
 
 #~# EXPECTED
-loop do
-  redo
-end
+redo

spec/lib/rufo/formatter_source_specs/retry.rb.spec

@@ -1,12 +1,6 @@
 #~# ORIGINAL retry
-begin
-rescue
 
 retry
-end
 
 #~# EXPECTED
-begin
-rescue
-  retry
-end
+retry

spec/lib/rufo/formatter_source_specs/yield.rb.spec

@@ -1,56 +1,36 @@
 #~# ORIGINAL yield
-def foo
 
 yield
-end
 
 #~# EXPECTED
-def foo
-  yield
-end
+yield
 
 #~# ORIGINAL
-def foo
 
 yield  1
-end
 
 #~# EXPECTED
-def foo
-  yield 1
-end
+yield 1
 
 #~# ORIGINAL
-def foo
 
 yield  1 , 2
-end
 
 #~# EXPECTED
-def foo
-  yield 1, 2
-end
+yield 1, 2
 
 #~# ORIGINAL
-def foo
 
 yield  1 ,
  2
-end
 
 #~# EXPECTED
-def foo
-  yield 1,
-        2
-end
+yield 1,
+      2
 
 #~# ORIGINAL
-def foo
 
 yield( 1 , 2 )
-end
 
 #~# EXPECTED
-def foo
-  yield(1, 2)
-end
+yield(1, 2)