fixing the trailing-else-in-switch-getting-sucked-in-bug, Issue 195.

lib/grammar.js

@@ -462,7 +462,7 @@
     Switch: [o("SWITCH Expression INDENT Whens OUTDENT", function() {
         return $4.rewrite_condition($2);
       }), o("SWITCH Expression INDENT Whens ELSE Block OUTDENT", function() {
-        return $4.rewrite_condition($2).add_else($6);
+        return $4.rewrite_condition($2).add_else($6, true);
       })
     ],
     // The inner list of whens.

lib/nodes.js

@@ -1246,9 +1246,15 @@
       return this;
     },
     // Rewrite a chain of IfNodes to add a default case as the final else.
-    add_else: function add_else(exprs) {
-      this.is_chain() ? this.else_body.add_else(exprs) : (this.else_body = exprs && exprs.unwrap());
-      this.children.push(exprs);
+    add_else: function add_else(exprs, statement) {
+      if (this.is_chain()) {
+        this.else_body.add_else(exprs);
+      } else {
+        if (!(statement)) {
+          exprs = exprs.unwrap();
+        }
+        this.children.push((this.else_body = exprs));
+      }
       return this;
     },
     // If the else_body is an IfNode itself, then we've got an if-else chain.

lib/parser.js

@@ -356,7 +356,7 @@ case 167:this.$ = (function () {
 break;
 case 168:this.$ = $$[$0-5+4-1].rewrite_condition($$[$0-5+2-1]);
 break;
-case 169:this.$ = $$[$0-7+4-1].rewrite_condition($$[$0-7+2-1]).add_else($$[$0-7+6-1]);
+case 169:this.$ = $$[$0-7+4-1].rewrite_condition($$[$0-7+2-1]).add_else($$[$0-7+6-1], true);
 break;
 case 170:this.$ = $$[$0-1+1-1];
 break;

src/grammar.coffee

@@ -394,7 +394,7 @@ grammar: {
   # Switch/When blocks.
   Switch: [
     o "SWITCH Expression INDENT Whens OUTDENT", -> $4.rewrite_condition($2)
-    o "SWITCH Expression INDENT Whens ELSE Block OUTDENT", -> $4.rewrite_condition($2).add_else($6)
+    o "SWITCH Expression INDENT Whens ELSE Block OUTDENT", -> $4.rewrite_condition($2).add_else($6, true)
   ]
 
   # The inner list of whens.

src/nodes.coffee

@@ -985,9 +985,12 @@ IfNode: exports.IfNode: inherit Node, {
     this
 
   # Rewrite a chain of IfNodes to add a default case as the final else.
-  add_else: (exprs) ->
-    if @is_chain() then @else_body.add_else(exprs) else @else_body: exprs and exprs.unwrap()
-    @children.push(exprs)
+  add_else: (exprs, statement) ->
+    if @is_chain()
+      @else_body.add_else exprs
+    else
+      exprs: exprs.unwrap() unless statement
+      @children.push @else_body: exprs
     this
 
   # If the else_body is an IfNode itself, then we've got an if-else chain.

test/test_switch.coffee

@@ -41,3 +41,13 @@ result: switch num += 5
 
 ok result
 
+
+# Ensure that trailing switch elses don't get rewritten.
+result: false
+switch "word"
+  when "one thing"
+    do_something()
+  else
+    result: true unless false
+
+ok result