REFACTOR: Split off raw handlebars helpers from compiler

This allows us to compile without Ember being present

app/assets/javascripts/discourse-common/lib/helpers.js.es6

@@ -1,4 +1,4 @@
-import { rawGet } from "discourse-common/lib/raw-handlebars";
+import { get } from "@ember/object";
 
 export function htmlHelper(fn) {
   return Ember.Helper.helper(function(...args) {
@@ -10,6 +10,17 @@ export function htmlHelper(fn) {
 
 const _helpers = {};
 
+function rawGet(ctx, property, options) {
+  if (options.types && options.data.view) {
+    var view = options.data.view;
+    return view.getStream
+      ? view.getStream(property).value()
+      : view.getAttr(property);
+  } else {
+    return get(ctx, property);
+  }
+}
+
 export function registerHelper(name, fn) {
   _helpers[name] = Ember.Helper.helper(fn);
 }

app/assets/javascripts/discourse-common/lib/raw-handlebars-helpers.js.es6

@@ -0,0 +1,44 @@
+import { get } from "@ember/object";
+
+export function registerRawHelpers(hbs, handlebarsClass) {
+  hbs.helper = function() {};
+  hbs.helpers = Object.create(handlebarsClass.helpers);
+
+  hbs.helpers["get"] = function(context, options) {
+    var firstContext = options.contexts[0];
+    var val = firstContext[context];
+
+    if (context.indexOf("controller.") === 0) {
+      context = context.slice(context.indexOf(".") + 1);
+    }
+
+    return val === undefined ? get(firstContext, context) : val;
+  };
+
+  // #each .. in support (as format is transformed to this)
+  hbs.registerHelper("each", function(
+    localName,
+    inKeyword,
+    contextName,
+    options
+  ) {
+    var list = get(this, contextName);
+    var output = [];
+    var innerContext = Object.create(this);
+    for (var i = 0; i < list.length; i++) {
+      innerContext[localName] = list[i];
+      output.push(options.fn(innerContext));
+    }
+    return output.join("");
+  });
+
+  function stringCompatHelper(fn) {
+    const old = hbs.helpers[fn];
+    hbs.helpers[fn] = function(context, options) {
+      return old.apply(this, [hbs.helpers.get(context, options), options]);
+    };
+  }
+  stringCompatHelper("if");
+  stringCompatHelper("unless");
+  stringCompatHelper("with");
+}

app/assets/javascripts/discourse-common/lib/raw-handlebars.js.es6

@@ -1,66 +1,9 @@
-import { get } from "@ember/object";
-
 // This is a mechanism for quickly rendering templates which is Ember aware
 // templates are highly compatible with Ember so you don't need to worry about calling "get"
 // and computed properties function, additionally it uses stringParams like Ember does
 
-// compat with ie8 in case this gets picked up elsewhere
-const objectCreate =
-  Object.create ||
-  function(parent) {
-    function F() {}
-    F.prototype = parent;
-    return new F();
-  };
-
 const RawHandlebars = Handlebars.create();
 
-RawHandlebars.helper = function() {};
-RawHandlebars.helpers = objectCreate(Handlebars.helpers);
-
-RawHandlebars.helpers["get"] = function(context, options) {
-  var firstContext = options.contexts[0];
-  var val = firstContext[context];
-
-  if (context.indexOf("controller.") === 0) {
-    context = context.slice(context.indexOf(".") + 1);
-  }
-
-  return val === undefined ? get(firstContext, context) : val;
-};
-
-// adds compatability so this works with stringParams
-function stringCompatHelper(fn) {
-  const old = RawHandlebars.helpers[fn];
-  RawHandlebars.helpers[fn] = function(context, options) {
-    return old.apply(this, [
-      RawHandlebars.helpers.get(context, options),
-      options
-    ]);
-  };
-}
-
-// #each .. in support (as format is transformed to this)
-RawHandlebars.registerHelper("each", function(
-  localName,
-  inKeyword,
-  contextName,
-  options
-) {
-  var list = get(this, contextName);
-  var output = [];
-  var innerContext = objectCreate(this);
-  for (var i = 0; i < list.length; i++) {
-    innerContext[localName] = list[i];
-    output.push(options.fn(innerContext));
-  }
-  return output.join("");
-});
-
-stringCompatHelper("if");
-stringCompatHelper("unless");
-stringCompatHelper("with");
-
 function buildPath(blk, args) {
   var result = {
     type: "PathExpression",
@@ -115,14 +58,14 @@ function replaceGet(ast) {
 
 if (Handlebars.Compiler) {
   RawHandlebars.Compiler = function() {};
-  RawHandlebars.Compiler.prototype = objectCreate(
+  RawHandlebars.Compiler.prototype = Object.create(
     Handlebars.Compiler.prototype
   );
   RawHandlebars.Compiler.prototype.compiler = RawHandlebars.Compiler;
 
   RawHandlebars.JavaScriptCompiler = function() {};
 
-  RawHandlebars.JavaScriptCompiler.prototype = objectCreate(
+  RawHandlebars.JavaScriptCompiler.prototype = Object.create(
     Handlebars.JavaScriptCompiler.prototype
   );
   RawHandlebars.JavaScriptCompiler.prototype.compiler =
@@ -173,17 +116,6 @@ if (Handlebars.Compiler) {
   };
 }
 
-RawHandlebars.get = function(ctx, property, options) {
-  if (options.types && options.data.view) {
-    var view = options.data.view;
-    return view.getStream
-      ? view.getStream(property).value()
-      : view.getAttr(property);
-  } else {
-    return get(ctx, property);
-  }
-};
-
 export function template() {
   return RawHandlebars.template.apply(this, arguments);
 }
@@ -196,8 +128,4 @@ export function compile() {
   return RawHandlebars.compile.apply(this, arguments);
 }
 
-export function rawGet() {
-  return RawHandlebars.get.apply(this, arguments);
-}
-
 export default RawHandlebars;

app/assets/javascripts/discourse/initializers/auto-load-modules.js.es6

@@ -1,4 +1,6 @@
 import { registerHelpers } from "discourse-common/lib/helpers";
+import RawHandlebars from "discourse-common/lib/raw-handlebars";
+import { registerRawHelpers } from "discourse-common/lib/raw-handlebars-helpers";
 
 export function autoLoadModules(container, registry) {
   Object.keys(requirejs.entries).forEach(entry => {
@@ -10,6 +12,7 @@ export function autoLoadModules(container, registry) {
     }
   });
   registerHelpers(registry);
+  registerRawHelpers(RawHandlebars, Handlebars);
 }
 
 export default {

lib/freedom_patches/raw_handlebars.rb

@@ -18,19 +18,19 @@ class Barber::Precompiler
       # very hacky but lets us use ES6. I'm ashamed of this code -RW
       transpiled = transpiled[0...transpiled.index('export ')]
 
-      @precompiler = StringIO.new <<END
-      var __RawHandlebars;
-      (function() {
-        #{transpiled};
-        __RawHandlebars = RawHandlebars;
-      })();
+      @precompiler = StringIO.new <<~END
+        var __RawHandlebars;
+        (function() {
+          #{transpiled};
+          __RawHandlebars = RawHandlebars;
+        })();
 
-      Barber = {
-        precompile: function(string) {
-          return __RawHandlebars.precompile(string, false).toString();
-        }
-      };
-END
+        Barber = {
+          precompile: function(string) {
+            return __RawHandlebars.precompile(string, false).toString();
+          }
+        };
+      END
     end
 
     @precompiler