Make actions use target=this implicitly

packages/ember-glimmer/lib/helpers/action.js

@@ -278,7 +278,7 @@ export class ClosureActionReference extends CachedReference {
     let { named, positional } = this.args;
     let positionalValues = positional.value();
 
-    let target = positionalValues[0];
+    let target = named.get('target').value();
     let rawActionRef = positional.at(1);
     let rawAction = positionalValues[1];
 
@@ -305,11 +305,6 @@ export class ClosureActionReference extends CachedReference {
 
       action = null;
 
-      if (named.has('target')) {
-        // on-change={{action 'setName' target=alternativeComponent}}
-        target = named.get('target').value();
-      }
-
       if (target['actions']) {
         action = target.actions[actionName];
       }

packages/ember-template-compiler/lib/plugins/transform-action-syntax.js

@@ -15,11 +15,13 @@
   with
 
   ```handlebars
- <button {{action this 'foo'}}>
- <button onblur={{action this 'foo'}}>
- <button onblur={{action this (action this 'foo') 'bar'}}>
+ <button {{action target=this 'foo'}}>
+ <button onblur={{action target=this 'foo'}}>
+ <button onblur={{action target=this (action target=this 'foo') 'bar'}}>
   ```
 
+  If an action already has a target it is left unmodified.
+
   @private
   @class TransformActionSyntax
 */
@@ -41,16 +43,19 @@ TransformActionSyntax.prototype.transform = function TransformActionSyntax_trans
     ElementModifierStatement(node) {
       if (isAction(node)) {
         insertThisAsFirstParam(node, b);
+        ensureTarget(node, b);
       }
     },
     MustacheStatement(node) {
       if (isAction(node)) {
         insertThisAsFirstParam(node, b);
+        ensureTarget(node, b);
       }
     },
     SubExpression(node) {
       if (isAction(node)) {
         insertThisAsFirstParam(node, b);
+        ensureTarget(node, b);
       }
     }
   });
@@ -62,6 +67,24 @@ function isAction(node) {
   return node.path.original === 'action';
 }
 
+function ensureTarget(node, builders) {
+  if (!hashPairForKey(node.hash, 'target')) {
+    let thisTarget = builders.pair('target', builders.path('this'));
+    node.hash.pairs.push(thisTarget);
+  }
+}
+
+function hashPairForKey(hash, key) {
+  for (let i = 0; i < hash.pairs.length; i++) {
+    let pair = hash.pairs[i];
+    if (pair.key === key) {
+      return pair;
+    }
+  }
+
+  return false;
+}
+
 function insertThisAsFirstParam(node, builders) {
   node.params.unshift(builders.path('this'));
 }