conditionals with no alternative now evaluate to 'undefined' instead of 'null'

lib/browser.js

@@ -18,7 +18,7 @@
       xhr.overrideMimeType('text/plain');
     }
     xhr.onreadystatechange = function() {
-      return xhr.readyState === 4 ? CoffeeScript.run(xhr.responseText, options) : null;
+      return xhr.readyState === 4 ? CoffeeScript.run(xhr.responseText, options) : undefined;
     };
     return xhr.send(null);
   };
@@ -30,7 +30,7 @@
         var script = _ref[_i];
         return script.type === 'text/coffeescript' ? (script.src ? CoffeeScript.load(script.src) : setTimeout(function() {
           return CoffeeScript.run(script.innerHTML);
-        })) : null;
+        })) : undefined;
       })();
     }
     return null;

lib/cake.js

@@ -65,7 +65,7 @@
       desc = task.description ? ("# " + (task.description)) : '';
       puts("cake " + (name) + (spaces) + " " + (desc));
     }
-    return switches.length ? puts(oparse.help()) : null;
+    return switches.length ? puts(oparse.help()) : undefined;
   };
   missingTask = function(task) {
     puts("No such task: \"" + (task) + "\"");

lib/command.js

@@ -77,7 +77,7 @@
                   fs.readFile(source, function(err, code) {
                     return compileScript(source, code.toString(), base);
                   });
-                  return opts.watch ? watch(source, base) : null;
+                  return opts.watch ? watch(source, base) : undefined;
                 }
               });
             });
@@ -115,7 +115,7 @@
       } else {
         t.output = CoffeeScript.compile(t.input, t.options);
         CoffeeScript.emit('success', task);
-        return o.print ? print(t.output) : (o.compile ? writeJs(t.file, t.output, base) : (o.lint ? lint(t.output) : null));
+        return o.print ? print(t.output) : (o.compile ? writeJs(t.file, t.output, base) : (o.lint ? lint(t.output) : undefined));
       }
     } catch (err) {
       CoffeeScript.emit('failure', err, task);
@@ -134,7 +134,7 @@
     code = '';
     stdin = process.openStdin();
     stdin.on('data', function(buffer) {
-      return buffer ? code += buffer.toString() : null;
+      return buffer ? code += buffer.toString() : undefined;
     });
     return stdin.on('end', function() {
       return compileScript('stdio', code);
@@ -168,7 +168,7 @@
         js = ' ';
       }
       return fs.writeFile(jsPath, js, function(err) {
-        return opts.compile && opts.watch ? puts("Compiled " + (source)) : null;
+        return opts.compile && opts.watch ? puts("Compiled " + (source)) : undefined;
       });
     };
     return path.exists(dir, function(exists) {

lib/lexer.js

@@ -294,7 +294,7 @@
       }
       this.i += value.length;
       prev = last(this.tokens);
-      spaced = ((prev != null) ? prev.spaced : null);
+      spaced = ((prev != null) ? prev.spaced : undefined);
       tag = value;
       if (value === '=') {
         if (include(JS_FORBIDDEN, val = this.value())) {

lib/nodes.js

@@ -55,7 +55,7 @@
           return [compiled, reference];
         }
       }).call(this);
-      if (((options != null) ? options.precompile : null)) {
+      if (((options != null) ? options.precompile : undefined)) {
         for (i = 0, _len = pair.length; i < _len; i++) {
           node = pair[i];
           (pair[i] = node.compile(o));
@@ -146,7 +146,7 @@
         if (func(child) === false) {
           return false;
         }
-        return child instanceof BaseNode && (crossScope || !(child instanceof CodeNode)) ? child.traverseChildren(crossScope, func) : null;
+        return child instanceof BaseNode && (crossScope || !(child instanceof CodeNode)) ? child.traverseChildren(crossScope, func) : undefined;
       });
     };
     BaseNode.prototype["class"] = 'BaseNode';
@@ -344,7 +344,7 @@
     ValueNode.prototype.cacheReference = function(o) {
       var base, bref, name, nref;
       name = last(this.properties);
-      if (!this.base.isComplex() && this.properties.length < 2 && !((name != null) ? name.isComplex() : null)) {
+      if (!this.base.isComplex() && this.properties.length < 2 && !((name != null) ? name.isComplex() : undefined)) {
         return [this, this];
       }
       base = new ValueNode(this.base, this.properties.slice(0, -1));
@@ -1132,7 +1132,7 @@
     };
     CodeNode.prototype.topSensitive = YES;
     CodeNode.prototype.traverseChildren = function(crossScope, func) {
-      return crossScope ? CodeNode.__super__.traverseChildren.call(this, crossScope, func) : null;
+      return crossScope ? CodeNode.__super__.traverseChildren.call(this, crossScope, func) : undefined;
     };
     return CodeNode;
   })();
@@ -1189,7 +1189,7 @@
         o.scope.assign(len, "arguments.length");
         variadic = o.scope.freeVariable('result');
         o.scope.assign(variadic, len + ' >= ' + this.arglength);
-        end = this.trailings.length ? (", " + (len) + " - " + (this.trailings.length)) : null;
+        end = this.trailings.length ? (", " + (len) + " - " + (this.trailings.length)) : undefined;
         _ref2 = this.trailings;
         for (idx = 0, _len = _ref2.length; idx < _len; idx++) {
           trailing = _ref2[idx];
@@ -1237,14 +1237,14 @@
   exports.WhileNode = (function() {
     WhileNode = function(condition, opts) {
       WhileNode.__super__.constructor.call(this);
-      if (((opts != null) ? opts.invert : null)) {
+      if (((opts != null) ? opts.invert : undefined)) {
         if (condition instanceof OpNode) {
           condition = new ParentheticalNode(condition);
         }
         condition = new OpNode('!', condition);
       }
       this.condition = condition;
-      this.guard = ((opts != null) ? opts.guard : null);
+      this.guard = ((opts != null) ? opts.guard : undefined);
       return this;
     };
     __extends(WhileNode, BaseNode);
@@ -1774,11 +1774,11 @@
     IfNode.prototype.topSensitive = YES;
     IfNode.prototype.bodyNode = function() {
       var _ref2;
-      return (((_ref2 = this.body) != null) ? _ref2.unwrap() : null);
+      return (((_ref2 = this.body) != null) ? _ref2.unwrap() : undefined);
     };
     IfNode.prototype.elseBodyNode = function() {
       var _ref2;
-      return (((_ref2 = this.elseBody) != null) ? _ref2.unwrap() : null);
+      return (((_ref2 = this.elseBody) != null) ? _ref2.unwrap() : undefined);
     };
     IfNode.prototype.addElse = function(elseBody, statement) {
       if (this.isChain) {
@@ -1849,7 +1849,7 @@
         this.elseBodyNode().tags.operation = true;
       }
       ifPart = this.condition.compile(o) + ' ? ' + this.bodyNode().compile(o);
-      elsePart = this.elseBody ? this.elseBodyNode().compile(o) : 'null';
+      elsePart = this.elseBody ? this.elseBodyNode().compile(o) : 'undefined';
       code = ("" + (ifPart) + " : " + (elsePart));
       return this.tags.operation ? ("(" + (code) + ")") : code;
     };

lib/rewriter.js

@@ -263,7 +263,7 @@
             return ('TERMINATOR' === (_ref = token[0]) || 'INDENT' === _ref);
           };
           action = function(token, i) {
-            return token[0] !== 'INDENT' ? (original[0] = 'POST_' + original[0]) : null;
+            return token[0] !== 'INDENT' ? (original[0] = 'POST_' + original[0]) : undefined;
           };
           this.detectEnd(i + 1, condition, action);
           return 1;
@@ -345,7 +345,7 @@
             }
             debt[mtag] += 1;
             val = [oppos, mtag === 'INDENT' ? match[1] : oppos];
-            if ((((_ref2 = this.tokens[i + 2]) != null) ? _ref2[0] === mtag : null)) {
+            if ((((_ref2 = this.tokens[i + 2]) != null) ? _ref2[0] === mtag : undefined)) {
               this.tokens.splice(i + 3, 0, val);
               stack.push(match);
             } else {

lib/scope.js

@@ -59,10 +59,10 @@
     Scope.prototype.check = function(name, options) {
       var _ref2, immediate;
       immediate = Object.prototype.hasOwnProperty.call(this.variables, name);
-      if (immediate || ((options != null) ? options.immediate : null)) {
+      if (immediate || ((options != null) ? options.immediate : undefined)) {
         return immediate;
       }
-      return !!(((_ref2 = this.parent) != null) ? _ref2.check(name) : null);
+      return !!(((_ref2 = this.parent) != null) ? _ref2.check(name) : undefined);
     };
     Scope.prototype.temporary = function(type, index) {
       return type.length > 1 ? '_' + type + (index > 1 ? index : '') : '_' + (index + parseInt(type, 36)).toString(36).replace(/\d/g, 'a');

src/nodes.coffee

@@ -459,6 +459,7 @@ exports.CallNode = class CallNode extends BaseNode
     else
       "#{name}.__super__.constructor"
 
+  # Soaked chained invocations unfold into if/else ternary structures.
   unfoldSoak: (o) ->
     call = this
     list = []
@@ -1585,7 +1586,7 @@ exports.IfNode = class IfNode extends BaseNode
     @bodyNode().tags.operation = @condition.tags.operation = yes
     @elseBodyNode().tags.operation = yes if @elseBody
     ifPart      = @condition.compile(o) + ' ? ' + @bodyNode().compile(o)
-    elsePart    = if @elseBody then @elseBodyNode().compile(o) else 'null'
+    elsePart    = if @elseBody then @elseBodyNode().compile(o) else 'undefined'
     code        = "#{ifPart} : #{elsePart}"
     if @tags.operation then "(#{code})" else code
 

test/test_existence.coffee

@@ -44,7 +44,7 @@ eq obj?.prop, "hello"
 eq obj?['prop'], "hello"
 eq obj.prop?.length, 5
 eq obj?.prop?['length'], 5
-eq obj?.prop?.non?.existent?.property, null
+eq obj?.prop?.non?.existent?.property, undefined
 
 
 # Soaks and caches method calls as well.
@@ -52,13 +52,13 @@ arr = ["--", "----"]
 
 eq arr.pop()?.length, 4
 eq arr.pop()?.length, 2
-eq arr.pop()?.length, null
-eq arr.pop()?.length?.non?.existent()?.property, null
+eq arr.pop()?.length, undefined
+eq arr.pop()?.length?.non?.existent()?.property, undefined
 
 
 # Soaks method calls safely.
 value = null
-eq value?.toString().toLowerCase(), null
+eq value?.toString().toLowerCase(), undefined
 
 value = 10
 eq value?.toString().toLowerCase(), '10'
@@ -78,7 +78,7 @@ ok counter is 3
 
 
 ident = (obj) -> obj
-eq ident(non?.existent().method()), null, 'soaks inner values'
+eq ident(non?.existent().method()), undefined, 'soaks inner values'
 
 
 # Soaks constructor invocations.
@@ -94,7 +94,7 @@ ok a is 1
 ok not value?.property?, 'safely checks existence on soaks'
 
 
-eq nothing?.value, null, 'safely calls values off of non-existent variables'
+eq nothing?.value, undefined, 'safely calls values off of non-existent variables'
 
 
 # Assign to the result of an exsitential operation with a minus.
@@ -132,7 +132,7 @@ ok (maybe_close 'string', 41)?() is undefined
 eq 2?(3), undefined
 
 #726
-eq calendar?[Date()], null
+eq calendar?[Date()], undefined
 
 #733
 a = b: {c: null}

test/test_if.coffee

@@ -66,7 +66,7 @@ ok result is undefined
 func = ->
   return if false then callback()
 
-ok func() is null
+ok func() is undefined
 
 func = ->
   return unless false then 100 else -100