Handle nested calls and function oneliners when chaining

Author: xixixao

lib/coffee-script/rewriter.js

@@ -159,6 +159,10 @@ class exports.Rewriter
         tokens.splice i, 0, generate 'CALL_END', ')'
         i += 1
 
+      endAllImplicitCalls = ->
+        while inImplicitCall()
+          endImplicitCall()
+
       startImplicitObject = (j, startsLine = yes) ->
         idx = j ? i
         stack.push ['{', idx, sameLine: yes, startsLine: startsLine, ours: yes]
@@ -281,10 +285,13 @@ class exports.Rewriter
       #     .g b
       #     .h a
       #
-      if (prevTag is 'OUTDENT' or prevToken.newLine) and inImplicitCall() and
-          tag in ['.', '?.', '::', '?::']
-        endImplicitCall()
-        return forward(1)
+      if inImplicitCall() and tag in CALL_CLOSERS
+        if prevTag is 'OUTDENT'
+          endImplicitCall()
+          return forward(1)
+        if prevToken.newLine
+          endAllImplicitCalls()
+          return forward(1)
 
       stackTop()[2].sameLine = no if inImplicitObject() and tag in LINEBREAKS
 
@@ -363,7 +370,8 @@ class exports.Rewriter
       token[1] isnt ';' and token[0] in SINGLE_CLOSERS and
       not (token[0] is 'TERMINATOR' and @tag(i + 1) in EXPRESSION_CLOSE) and
       not (token[0] is 'ELSE' and starter isnt 'THEN') and
-      not (token[0] in ['CATCH', 'FINALLY'] and starter in ['->', '=>'])
+      not (token[0] in ['CATCH', 'FINALLY'] and starter in ['->', '=>']) or
+      token[0] in CALL_CLOSERS and @tokens[i - 1].newLine
 
     action = (token, i) ->
       @tokens.splice (if @tag(i - 1) is ',' then i - 1 else i), 0, outdent
@@ -478,3 +486,6 @@ SINGLE_CLOSERS   = ['TERMINATOR', 'CATCH', 'FINALLY', 'ELSE', 'OUTDENT', 'LEADIN
 
 # Tokens that end a line.
 LINEBREAKS       = ['TERMINATOR', 'INDENT', 'OUTDENT']
+
+# Tokens that close open calls when they follow a newline.
+CALL_CLOSERS = ['.', '?.', '::', '?::']

src/rewriter.coffee

@@ -78,11 +78,24 @@ test "#1495, method call chaining", ->
     'aaabbbccc'.replace /(\w)\1\1/g, '$1$1'
                .replace /([abc])\1/g, '$1'
 
-  # Unreadable code, not a real-life use case
-  result = str.split ''.
+  # Nested calls
+  result = [1..3]
+    .slice Math.max 0, 1
+    .concat [3]
+  arrayEq result, [2, 3, 3]
+
+  # Single line function arguments.
+  result = [1..6]
+    .map (x) -> x * x
+    .filter (x) -> x % 2 is 0
+    .reverse()
+  arrayEq result, [36, 16, 4]
+
+  # The parens are forced
+  result = str.split(''.
     split ''
-    .join('')
-    .join ', '
+    .join ''
+  ).join ', '
   eq 'a, b, c', result
 
 # Operators