wip: ember 1.13 support

Starting work on support for Ember 1.13. Glimmer breaks the old
helper and adds a new `Ember.Helper` with more of the power we
need.

As of this commit, the beta build is still breaking because there's
something wrong with the helper registration.

.travis.yml

@@ -18,7 +18,6 @@ env:
 matrix:
   fast_finish: true
   allow_failures:
-    - env: EMBER_TRY_SCENARIO=ember-beta
     - env: EMBER_TRY_SCENARIO=ember-canary
 
 before_install:

addon/helper.js

@@ -1,32 +1,22 @@
 import Ember from "ember";
-import Stream from "./stream";
-import { readHash } from "./stream";
 
-// @public
-export default function t(params, hash, options, env) {
-  const i18n = env.data.view.container.lookup('service:i18n');
-  const i18nKey = params[0];
+var Helper = null;
 
-  var out = new Stream(function() {
-    return i18n.t(i18nKey, readHash(hash));
-  });
+if (Ember.Helper) {
+  Helper = Ember.Helper.extend({
+    i18n: Ember.inject.service(),
+    _locale: Ember.computed.readOnly('i18n.locale'),
 
-  // observe any hash arguments that are streams:
-  Ember.keys(hash).forEach(function(key) {
-    const value = hash[key];
+    compute: function(params) {
+      const [ key, interpolations ] = params;
+      const i18n = this.get('i18n');
+      return i18n.t(key, interpolations);
+    },
 
-    if (value && value.isStream) {
-      value.subscribe(out.notify, out);
-    }
+    _recomputeOnLocaleChange: Ember.observer('_locale', function() {
+      this.recompute();
+    })
   });
-
-  // observe the locale:
-  i18n.localeStream.subscribe(out.notify, out);
-
-  // if the i18n key itself is dynamic, observe it:
-  if (i18nKey.isStream) {
-    i18nKey.subscribe(out.notify, out);
-  }
-
-  return out;
 }
+
+export default Helper;

addon/legacy-helper.js

@@ -0,0 +1,38 @@
+import Ember from "ember";
+import Stream from "./stream";
+import { readHash } from "./stream";
+
+var helper = null;
+
+if (Ember.Helper == null) {
+  // @public
+  helper = function tHelper(params, hash, options, env) {
+    const i18n = env.data.view.container.lookup('service:i18n');
+    const i18nKey = params[0];
+
+    var out = new Stream(function() {
+      return i18n.t(i18nKey, readHash(hash));
+    });
+
+    // observe any hash arguments that are streams:
+    Ember.keys(hash).forEach(function(key) {
+      const value = hash[key];
+
+      if (value && value.isStream) {
+        value.subscribe(out.notify, out);
+      }
+    });
+
+    // observe the locale:
+    i18n.localeStream.subscribe(out.notify, out);
+
+    // if the i18n key itself is dynamic, observe it:
+    if (i18nKey.isStream) {
+      i18nKey.subscribe(out.notify, out);
+    }
+
+    return out;
+  };
+}
+
+export default helper;

app/instance-initializers/ember-i18n.js

@@ -1,5 +1,6 @@
 import Ember from "ember";
-import helper from "ember-i18n/helper";
+import legacyHelper from "ember-i18n/legacy-helper";
+import Helper from "ember-i18n/helper";
 import ENV from '../config/environment';
 
 export default {
@@ -13,7 +14,14 @@ export default {
     }
     instance.container.lookup('service:i18n').set('locale', defaultLocale);
 
-    Ember.HTMLBars._registerHelper('t', helper);
+    if (legacyHelper != null) {
+      Ember.HTMLBars._registerHelper('t', legacyHelper);
+    }
+
+    if (Helper != null) {
+      instance.registry.register('helper:t', Helper);
+    }
+
     instance.registry.injection('component', 'i18n', 'service:i18n');
     instance.registry.injection('controller', 'i18n', 'service:i18n');
     instance.registry.injection('route', 'i18n', 'service:i18n');