[CS2] Throw an error for ambiguous get or set keywords or function calls

src/lexer.coffee

@@ -132,7 +132,7 @@ exports.Lexer = class Lexer
       @token 'DEFAULT', id
       return id.length
 
-    [..., prev] = @tokens
+    prev = @prev()
 
     tag =
       if colon or prev? and
@@ -170,6 +170,16 @@ exports.Lexer = class Lexer
        isForFrom(prev)
       tag = 'FORFROM'
       @seenFor = no
+    # Throw an error on attempts to use `get` or `set` as keywords, or
+    # what CoffeeScript would normally interpret as calls to functions named
+    # `get` or `set`, i.e. `get({foo: function () {}})`
+    else if tag is 'PROPERTY' and prev
+      if prev.spaced and prev[0] in CALLABLE and /^[gs]et$/.test(prev[1])
+        @error "'#{prev[1]}' cannot be used as a keyword, or as a function call without parentheses", prev[2]
+      else
+        prevprev = @tokens[@tokens.length - 2]
+        if prev[0] in ['@', 'THIS'] and prevprev and prevprev.spaced and /^[gs]et$/.test(prevprev[1])
+          @error "'#{prevprev[1]}' cannot be used as a keyword, or as a function call without parentheses", prevprev[2]
 
     if tag is 'IDENTIFIER' and id in RESERVED
       @error "reserved word '#{id}'", length: id.length
@@ -235,10 +245,15 @@ exports.Lexer = class Lexer
     [quote] = STRING_START.exec(@chunk) || []
     return 0 unless quote
 
+    prev = @prev()
+
     # If the preceding token is `from` and this is an import or export statement,
     # properly tag the `from`.
-    if @tokens.length and @value() is 'from' and (@seenImport or @seenExport)
-      @tokens[@tokens.length - 1][0] = 'FROM'
+    if prev and @value() is 'from' and (@seenImport or @seenExport)
+      prev[0] = 'FROM'
+
+    if prev and prev.spaced and prev[0] in CALLABLE and /^[gs]et$/.test(prev[1])
+      @error "'#{prev[1]}' cannot be used as a keyword, or as a function call without parentheses", prev[2]
 
     regex = switch quote
       when "'"   then STRING_SINGLE
@@ -318,7 +333,7 @@ exports.Lexer = class Lexer
         [regex, body, closed] = match
         @validateEscapes body, isRegex: yes, offsetInChunk: 1
         index = regex.length
-        [..., prev] = @tokens
+        prev = @prev()
         if prev
           if prev.spaced and prev[0] in CALLABLE
             return 0 if not closed or POSSIBLY_DIVISION.test regex
@@ -443,7 +458,7 @@ exports.Lexer = class Lexer
   whitespaceToken: ->
     return 0 unless (match = WHITESPACE.exec @chunk) or
                     (nline = @chunk.charAt(0) is '\n')
-    [..., prev] = @tokens
+    prev = @prev()
     prev[if match then 'spaced' else 'newLine'] = true if prev
     if match then match[0].length else 0
 
@@ -471,7 +486,7 @@ exports.Lexer = class Lexer
     else
       value = @chunk.charAt 0
     tag  = value
-    [..., prev] = @tokens
+    prev = @prev()
 
     if prev and value in ['=', COMPOUND_ASSIGN...]
       skipToken = false
@@ -761,6 +776,11 @@ exports.Lexer = class Lexer
     [..., token] = @tokens
     token?[1]
 
+  # Get the previous token in the token stream.
+  prev: ->
+    [..., token] = @tokens
+    token if token?
+
   # Are we in the midst of an unfinished expression?
   unfinished: ->
     LINE_CONTINUER.test(@chunk) or

src/nodes.coffee

@@ -764,7 +764,7 @@ exports.Call = class Call extends Base
   constructor: (@variable, @args = [], @soak) ->
     super()
 
-    @isNew    = false
+    @isNew = no
     if @variable instanceof Value and @variable.isNotCallable()
       @variable.error "literal is not a function"