Implement strip opcode

lib/handlebars/compiler/javascript-compiler.js

@@ -75,6 +75,11 @@ JavaScriptCompiler.prototype = {
       } else {
         this[opcode.opcode].apply(this, opcode.args);
       }
+
+      // Reset the stripNext flag if it was not set by this operation.
+      if (opcode.opcode !== this.stripNext) {
+        this.stripNext = false;
+      }
     }
 
     // Flush any trailing content that might be pending.
@@ -246,6 +251,20 @@ JavaScriptCompiler.prototype = {
     this.pendingContent = content;
   },
 
+  // [strip]
+  //
+  // On stack, before: ...
+  // On stack, after: ...
+  //
+  // Removes any trailing whitespace from the prior content node and flags
+  // the next operation for stripping if it is a content node.
+  strip: function() {
+    if (this.pendingContent) {
+      this.pendingContent = this.pendingContent.replace(/\s+$/, '');
+    }
+    this.stripNext = 'strip';
+  },
+
   // [append]
   //
   // On stack, before: value, ...