REFACTOR: Raw Handlebars ported to ES6

app/assets/javascripts/discourse/lib/ember_compat_handlebars.js

@@ -1,160 +0,0 @@
-// keep IIF for simpler testing
-
-// EmberCompatHandlebars 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
-
-(function(){
-
-  // compat with ie8 in case this gets picked up elsewhere
-  var objectCreate = Object.create || function(parent) {
-    function F() {}
-    F.prototype = parent;
-    return new F();
-  };
-
-
-  var 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 (val && val.isDescriptor) { return Em.get(firstContext, context); }
-    val = val === undefined ? Em.get(firstContext, context): val;
-    return val;
-  };
-
-  // adds compatability so this works with stringParams
-  var stringCompatHelper = function(fn){
-
-    var 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 = Em.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('');
-  });
-
-  stringCompatHelper("if");
-  stringCompatHelper("unless");
-  stringCompatHelper("with");
-
-
-  if (Handlebars.Compiler) {
-    RawHandlebars.Compiler = function() {};
-    RawHandlebars.Compiler.prototype = objectCreate(Handlebars.Compiler.prototype);
-    RawHandlebars.Compiler.prototype.compiler = RawHandlebars.Compiler;
-
-    RawHandlebars.JavaScriptCompiler = function() {};
-
-    RawHandlebars.JavaScriptCompiler.prototype = objectCreate(Handlebars.JavaScriptCompiler.prototype);
-    RawHandlebars.JavaScriptCompiler.prototype.compiler = RawHandlebars.JavaScriptCompiler;
-    RawHandlebars.JavaScriptCompiler.prototype.namespace = "Discourse.EmberCompatHandlebars";
-
-    function buildPath(blk, args) {
-
-      var result = { type: "PathExpression",
-                     data: false,
-                     depth: blk.path.depth,
-                     loc: blk.path.loc };
-
-      // Server side precompile doesn't have jquery.extend
-      Object.keys(args).forEach(function (a) {
-        result[a] = args[a];
-      });
-
-      return result;
-    }
-
-    function replaceGet(ast) {
-      var visitor = new Handlebars.Visitor();
-      visitor.mutating = true;
-
-      visitor.MustacheStatement = function(mustache) {
-        if (!(mustache.params.length || mustache.hash)) {
-          mustache.params[0] = mustache.path;
-          mustache.path = buildPath(mustache, { parts: ['get'], original: 'get', strict: true, falsy: true });
-        }
-        return Handlebars.Visitor.prototype.MustacheStatement.call(this, mustache);
-      };
-
-      // rewrite `each x as |y|` as each y in x`
-      // This allows us to use the same syntax in all templates
-      visitor.BlockStatement = function(block) {
-        if (block.path.original === 'each' && block.params.length === 1) {
-          var paramName = block.program.blockParams[0];
-          block.params = [ buildPath(block, { original: paramName }),
-                           { type: "CommentStatement", value: "in" },
-                           block.params[0] ];
-          delete block.program.blockParams;
-        }
-
-        return Handlebars.Visitor.prototype.BlockStatement.call(this, block);
-      };
-
-      visitor.accept(ast);
-    }
-
-    RawHandlebars.precompile = function(value, asObject) {
-      var ast = Handlebars.parse(value);
-      replaceGet(ast);
-
-      var options = {
-        knownHelpers: {
-          get: true
-        },
-        data: true,
-        stringParams: true
-      };
-
-      asObject = asObject === undefined ? true : asObject;
-
-      var environment = new RawHandlebars.Compiler().compile(ast, options);
-      return new RawHandlebars.JavaScriptCompiler().compile(environment, options, undefined, asObject);
-    };
-
-    RawHandlebars.compile = function(string) {
-      var ast = Handlebars.parse(string);
-      replaceGet(ast);
-
-      // this forces us to rewrite helpers
-      var options = {  data: true, stringParams: true };
-      var environment = new RawHandlebars.Compiler().compile(ast, options);
-      var templateSpec = new RawHandlebars.JavaScriptCompiler().compile(environment, options, undefined, true);
-
-      var template = RawHandlebars.template(templateSpec);
-      template.isMethod = false;
-
-      return template;
-    };
-  }
-
-  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 Ember.get(ctx, property);
-    }
-  };
-
-  Discourse.EmberCompatHandlebars = RawHandlebars;
-
-})();

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

@@ -1,3 +1,5 @@
+import { get } from 'discourse/lib/raw-handlebars';
+
 // `Ember.Helper` is only available in versions after 1.12
 export function htmlHelper(fn) {
   if (Ember.Helper) {
@@ -15,8 +17,6 @@ export function registerHelper(name, fn) {
   Ember.HTMLBars._registerHelper(name, fn);
 }
 
-const get = Discourse.EmberCompatHandlebars.get;
-
 function resolveParams(ctx, options) {
   let params = {};
   const hash = options.hash;

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

@@ -0,0 +1,164 @@
+// 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 (val && val.isDescriptor) { return Em.get(firstContext, context); }
+  val = val === undefined ? Em.get(firstContext, context): val;
+  return 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 = Em.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('');
+});
+
+stringCompatHelper("if");
+stringCompatHelper("unless");
+stringCompatHelper("with");
+
+
+if (Handlebars.Compiler) {
+  RawHandlebars.Compiler = function() {};
+  RawHandlebars.Compiler.prototype = objectCreate(Handlebars.Compiler.prototype);
+  RawHandlebars.Compiler.prototype.compiler = RawHandlebars.Compiler;
+
+  RawHandlebars.JavaScriptCompiler = function() {};
+
+  RawHandlebars.JavaScriptCompiler.prototype = objectCreate(Handlebars.JavaScriptCompiler.prototype);
+  RawHandlebars.JavaScriptCompiler.prototype.compiler = RawHandlebars.JavaScriptCompiler;
+  RawHandlebars.JavaScriptCompiler.prototype.namespace = "RawHandlebars";
+
+  function buildPath(blk, args) {
+
+    var result = { type: "PathExpression",
+                   data: false,
+                   depth: blk.path.depth,
+                   loc: blk.path.loc };
+
+    // Server side precompile doesn't have jquery.extend
+    Object.keys(args).forEach(function (a) {
+      result[a] = args[a];
+    });
+
+    return result;
+  }
+
+  function replaceGet(ast) {
+    var visitor = new Handlebars.Visitor();
+    visitor.mutating = true;
+
+    visitor.MustacheStatement = function(mustache) {
+      if (!(mustache.params.length || mustache.hash)) {
+        mustache.params[0] = mustache.path;
+        mustache.path = buildPath(mustache, { parts: ['get'], original: 'get', strict: true, falsy: true });
+      }
+      return Handlebars.Visitor.prototype.MustacheStatement.call(this, mustache);
+    };
+
+    // rewrite `each x as |y|` as each y in x`
+    // This allows us to use the same syntax in all templates
+    visitor.BlockStatement = function(block) {
+      if (block.path.original === 'each' && block.params.length === 1) {
+        var paramName = block.program.blockParams[0];
+        block.params = [ buildPath(block, { original: paramName }),
+                         { type: "CommentStatement", value: "in" },
+                         block.params[0] ];
+        delete block.program.blockParams;
+      }
+
+      return Handlebars.Visitor.prototype.BlockStatement.call(this, block);
+    };
+
+    visitor.accept(ast);
+  }
+
+  RawHandlebars.precompile = function(value, asObject) {
+    var ast = Handlebars.parse(value);
+    replaceGet(ast);
+
+    var options = {
+      knownHelpers: {
+        get: true
+      },
+      data: true,
+      stringParams: true
+    };
+
+    asObject = asObject === undefined ? true : asObject;
+
+    var environment = new RawHandlebars.Compiler().compile(ast, options);
+    return new RawHandlebars.JavaScriptCompiler().compile(environment, options, undefined, asObject);
+  };
+
+  RawHandlebars.compile = function(string) {
+    var ast = Handlebars.parse(string);
+    replaceGet(ast);
+
+    // this forces us to rewrite helpers
+    var options = {  data: true, stringParams: true };
+    var environment = new RawHandlebars.Compiler().compile(ast, options);
+    var templateSpec = new RawHandlebars.JavaScriptCompiler().compile(environment, options, undefined, true);
+
+    var template = RawHandlebars.template(templateSpec);
+    template.isMethod = false;
+
+    return template;
+  };
+
+  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 Ember.get(ctx, property);
+    }
+  };
+}
+
+export function precompile(value, asObject) {
+  return RawHandlebars.precompile(value, asObject);
+}
+
+export function compile(string) {
+  return RawHandlebars.compile(string);
+}
+
+export function get(ctx, property, options) {
+  return RawHandlebars.get(ctx, property, options);
+}
+
+export default RawHandlebars;

app/assets/javascripts/main_include.js

@@ -21,7 +21,7 @@
 //= require ./discourse/lib/helpers
 //= require ./discourse/helpers/i18n
 //= require ./discourse/helpers/fa-icon
-//= require ./discourse/lib/ember_compat_handlebars
+//= require ./discourse/lib/raw-handlebars
 //= require ./discourse/lib/helpers
 //= require ./discourse/lib/computed
 //= require ./discourse/lib/formatter

app/models/site_customization.rb

@@ -44,7 +44,7 @@ PLUGIN_API_JS
       name = node["name"] || node["data-template-name"] || "broken"
       precompiled =
         if name =~ /\.raw$/
-          "Discourse.EmberCompatHandlebars.template(#{Barber::Precompiler.compile(node.inner_html)})"
+          "RawHandlebars.template(#{Barber::Precompiler.compile(node.inner_html)})"
         else
           "Ember.HTMLBars.template(#{Barber::Ember::Precompiler.compile(node.inner_html)})"
         end

lib/freedom_patches/raw_handlebars.rb

@@ -2,19 +2,36 @@
 
 class Barber::Precompiler
   def sources
-    [File.open("#{Rails.root}/vendor/assets/javascripts/handlebars.js"), precompiler]
+    [File.open("#{Rails.root}/vendor/assets/javascripts/handlebars.js"),
+     precompiler]
   end
 
   def precompiler
-  @precompiler ||= StringIO.new <<END
-    var Discourse = {};
-    #{File.read(Rails.root + "app/assets/javascripts/discourse/lib/ember_compat_handlebars.js")}
-    var Barber = {
-      precompile: function(string) {
-        return Discourse.EmberCompatHandlebars.precompile(string,false).toString();
-      }
-    };
+    if !@precompiler
+
+      source = File.read("#{Rails.root}/app/assets/javascripts/discourse/lib/raw-handlebars.js.es6")
+      template = Tilt::ES6ModuleTranspilerTemplate.new {}
+      transpiled = template.babel_transpile(source)
+
+      # very hacky but lets us use ES6. I'm ashamed of this code -RW
+      transpiled.gsub!(/^export .*$/, '')
+
+      @precompiler = StringIO.new <<END
+      var __RawHandlebars;
+      (function() {
+        #{transpiled};
+        __RawHandlebars = RawHandlebars;
+      })();
+
+      Barber = {
+        precompile: function(string) {
+          return __RawHandlebars.precompile(string, false).toString();
+        }
+      };
 END
+    end
+
+    @precompiler
   end
 end
 
@@ -27,7 +44,7 @@ module Discourse
         end
 
         def compile_handlebars(string)
-          "Discourse.EmberCompatHandlebars.compile(#{indent(string).inspect});"
+          "require('discourse/lib/raw-handlebars').compile(#{indent(string).inspect});"
         end
       end
     end

spec/models/site_customization_spec.rb

@@ -109,8 +109,8 @@ HTML
     c = SiteCustomization.create!(user_id: -1, name: "test", head_tag: with_template, body_tag: with_template)
     expect(c.head_tag_baked).to match(/HTMLBars/)
     expect(c.body_tag_baked).to match(/HTMLBars/)
-    expect(c.body_tag_baked).to match(/EmberCompatHandlebars/)
-    expect(c.head_tag_baked).to match(/EmberCompatHandlebars/)
+    expect(c.body_tag_baked).to match(/RawHandlebars/)
+    expect(c.head_tag_baked).to match(/RawHandlebars/)
   end
 
   it 'should create body_tag_baked on demand if needed' do

test/javascripts/acceptance/category-hashtag-test.js.es6

@@ -1,18 +1,6 @@
 import { acceptance } from "helpers/qunit-helpers";
 
-acceptance("Category hashtag", {
-  loggedIn: true,
-  setup() {
-    const response = (object) => {
-      return [
-        200,
-        {"Content-Type": "application/json"},
-        object
-      ];
-    };
-
-  }
-});
+acceptance("Category hashtag", { loggedIn: true });
 
 test("category hashtag is cooked properly", () => {
   visit("/t/internationalization-localization/280");