Restrict indented return arg to object (#4605)

* throw multiline implicit object [Fixes #3199]

* only return

* fix from code review

* test error on non-object

* test error on call indented non-object

* unique test names

lib/coffee-script/grammar.js

@@ -143,6 +143,8 @@
     Return: [
       o('RETURN Expression', function() {
         return new Return($2);
+      }), o('RETURN INDENT Object OUTDENT', function() {
+        return new Return(new Value($3));
       }), o('RETURN', function() {
         return new Return;
       })

lib/coffee-script/lexer.js

@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 1.12.6
 (function() {
-  var BOM, BOOL, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_ALIAS_MAP, COFFEE_KEYWORDS, COMMENT, COMPARE, COMPOUND_ASSIGN, HERECOMMENT_ILLEGAL, HEREDOC_DOUBLE, HEREDOC_INDENT, HEREDOC_SINGLE, HEREGEX, HEREGEX_OMIT, HERE_JSTOKEN, IDENTIFIER, INDENTABLE_CLOSERS, INDEXABLE, INVERSES, JSTOKEN, JS_KEYWORDS, LEADING_BLANK_LINE, LINE_BREAK, LINE_CONTINUER, Lexer, MATH, MULTI_DENT, NOT_REGEX, NUMBER, OPERATOR, POSSIBLY_DIVISION, REGEX, REGEX_FLAGS, REGEX_ILLEGAL, REGEX_INVALID_ESCAPE, RELATION, RESERVED, Rewriter, SHIFT, SIMPLE_STRING_OMIT, STRICT_PROSCRIBED, STRING_DOUBLE, STRING_INVALID_ESCAPE, STRING_OMIT, STRING_SINGLE, STRING_START, TRAILING_BLANK_LINE, TRAILING_SPACES, UNARY, UNARY_MATH, UNICODE_CODE_POINT_ESCAPE, VALID_FLAGS, WHITESPACE, compact, count, invertLiterate, isForFrom, isUnassignable, key, locationDataToString, ref, ref1, repeat, starts, throwSyntaxError,
+  var BOM, BOOL, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_ALIAS_MAP, COFFEE_KEYWORDS, COMMENT, COMPARE, COMPOUND_ASSIGN, HERECOMMENT_ILLEGAL, HEREDOC_DOUBLE, HEREDOC_INDENT, HEREDOC_SINGLE, HEREGEX, HEREGEX_OMIT, HERE_JSTOKEN, IDENTIFIER, INDENTABLE_CLOSERS, INDEXABLE, INVERSES, JSTOKEN, JS_KEYWORDS, LEADING_BLANK_LINE, LINE_BREAK, LINE_CONTINUER, Lexer, MATH, MULTI_DENT, NOT_REGEX, NUMBER, OPERATOR, POSSIBLY_DIVISION, REGEX, REGEX_FLAGS, REGEX_ILLEGAL, REGEX_INVALID_ESCAPE, RELATION, RESERVED, Rewriter, SHIFT, SIMPLE_STRING_OMIT, STRICT_PROSCRIBED, STRING_DOUBLE, STRING_INVALID_ESCAPE, STRING_OMIT, STRING_SINGLE, STRING_START, TRAILING_BLANK_LINE, TRAILING_SPACES, UNARY, UNARY_MATH, UNFINISHED, UNICODE_CODE_POINT_ESCAPE, VALID_FLAGS, WHITESPACE, compact, count, invertLiterate, isForFrom, isUnassignable, key, locationDataToString, ref, ref1, repeat, starts, throwSyntaxError,
     indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; },
     slice = [].slice;
 
@@ -450,7 +450,7 @@
         return indent.length;
       }
       if (size > this.indent) {
-        if (noNewlines || this.tag() === 'RETURN') {
+        if (noNewlines) {
           this.indebt = size - this.indent;
           this.suppressNewlines();
           return indent.length;
@@ -874,7 +874,7 @@
 
     Lexer.prototype.unfinished = function() {
       var ref2;
-      return LINE_CONTINUER.test(this.chunk) || ((ref2 = this.tag()) === '\\' || ref2 === '.' || ref2 === '?.' || ref2 === '?::' || ref2 === 'UNARY' || ref2 === 'MATH' || ref2 === 'UNARY_MATH' || ref2 === '+' || ref2 === '-' || ref2 === '**' || ref2 === 'SHIFT' || ref2 === 'RELATION' || ref2 === 'COMPARE' || ref2 === '&' || ref2 === '^' || ref2 === '|' || ref2 === '&&' || ref2 === '||' || ref2 === 'BIN?' || ref2 === 'THROW' || ref2 === 'EXTENDS' || ref2 === 'DEFAULT');
+      return LINE_CONTINUER.test(this.chunk) || (ref2 = this.tag(), indexOf.call(UNFINISHED, ref2) >= 0);
     };
 
     Lexer.prototype.formatString = function(str, options) {
@@ -1161,4 +1161,6 @@
 
   INDENTABLE_CLOSERS = [')', '}', ']'];
 
+  UNFINISHED = ['\\', '.', '?.', '?::', 'UNARY', 'MATH', 'UNARY_MATH', '+', '-', '**', 'SHIFT', 'RELATION', 'COMPARE', '&', '^', '|', '&&', '||', 'BIN?', 'THROW', 'EXTENDS', 'DEFAULT'];
+
 }).call(this);

src/grammar.coffee

@@ -211,6 +211,7 @@ grammar =
   # A return statement from a function body.
   Return: [
     o 'RETURN Expression',                      -> new Return $2
+    o 'RETURN INDENT Object OUTDENT',           -> new Return new Value $3
     o 'RETURN',                                 -> new Return
   ]
 

src/lexer.coffee

@@ -378,7 +378,7 @@ exports.Lexer = class Lexer
       return indent.length
 
     if size > @indent
-      if noNewlines or @tag() is 'RETURN'
+      if noNewlines
         @indebt = size - @indent
         @suppressNewlines()
         return indent.length
@@ -759,9 +759,7 @@ exports.Lexer = class Lexer
   # Are we in the midst of an unfinished expression?
   unfinished: ->
     LINE_CONTINUER.test(@chunk) or
-    @tag() in ['\\', '.', '?.', '?::', 'UNARY', 'MATH', 'UNARY_MATH', '+', '-',
-               '**', 'SHIFT', 'RELATION', 'COMPARE', '&', '^', '|', '&&', '||',
-               'BIN?', 'THROW', 'EXTENDS', 'DEFAULT']
+    @tag() in UNFINISHED
 
   formatString: (str, options) ->
     @replaceUnicodeCodePointEscapes str.replace(STRING_OMIT, '$1'), options
@@ -1094,3 +1092,8 @@ LINE_BREAK = ['INDENT', 'OUTDENT', 'TERMINATOR']
 
 # Additional indent in front of these is ignored.
 INDENTABLE_CLOSERS = [')', '}', ']']
+
+# Tokens that, when appearing at the end of a line, suppress a following TERMINATOR/INDENT token
+UNFINISHED = ['\\', '.', '?.', '?::', 'UNARY', 'MATH', 'UNARY_MATH', '+', '-',
+           '**', 'SHIFT', 'RELATION', 'COMPARE', '&', '^', '|', '&&', '||',
+           'BIN?', 'THROW', 'EXTENDS', 'DEFAULT']

test/error_messages.coffee

@@ -1328,3 +1328,45 @@ test "#4283: error message for implicit call", ->
     console.log {search, users, contacts users_to_display}
                                 ^^^^^^^^
   '''
+
+test "#3199: error message for call indented non-object", ->
+  assertErrorFormat '''
+    fn = ->
+    fn
+      1
+  ''', '''
+    [stdin]:3:1: error: unexpected indentation
+      1
+    ^^
+  '''
+
+test "#3199: error message for call indented comprehension", ->
+  assertErrorFormat '''
+    fn = ->
+    fn
+      x for x in [1, 2, 3]
+  ''', '''
+    [stdin]:3:1: error: unexpected indentation
+      x for x in [1, 2, 3]
+    ^^
+  '''
+
+test "#3199: error message for return indented non-object", ->
+  assertErrorFormat '''
+    return
+      1
+  ''', '''
+    [stdin]:2:3: error: unexpected number
+      1
+      ^
+  '''
+
+test "#3199: error message for return indented comprehension", ->
+  assertErrorFormat '''
+    return
+      x for x in [1, 2, 3]
+  ''', '''
+    [stdin]:2:3: error: unexpected identifier
+      x for x in [1, 2, 3]
+      ^
+  '''

test/formatting.coffee

@@ -298,3 +298,10 @@ test "#1275: allow indentation before closing brackets", ->
     a = 1
    )
   eq 1, a
+
+test "#3199: return multiline implicit object", ->
+  y = do ->
+    if no then return
+      type: 'a'
+      msg: 'b'
+  eq undefined, y