[BUGFIX lts] Restore {{this.attrs.foo}} deprecation

packages/@ember/-internals/glimmer/tests/integration/components/curly-components-test.js

@@ -1270,10 +1270,13 @@ moduleFor(
       }, "Using {{attrs}} to reference named arguments is not supported. {{attrs.someProp}} should be updated to {{@someProp}}. ('my-app/templates/components/non-block.hbs' @ L1:C24) ");
     }
 
+    // Perhaps change this test to `{{this.attrs.someProp.value}}` when removing the deprecation?
     ['@test non-block with properties on this.attrs']() {
-      this.registerComponent('non-block', {
-        template: 'In layout - someProp: {{this.attrs.someProp}}',
-      });
+      expectDeprecation(() => {
+        this.registerComponent('non-block', {
+          template: 'In layout - someProp: {{this.attrs.someProp}}',
+        });
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs.someProp}} should be updated to {{@someProp}}./);
 
       this.render('{{non-block someProp=this.prop}}', {
         prop: 'something here',
@@ -1477,21 +1480,24 @@ moduleFor(
       );
     }
 
+    // Perhaps change this test to `{{this.attrs.foo.value}}` when removing the deprecation?
     ['@test this.attrs.foo === @foo === foo']() {
-      this.registerComponent('foo-bar', {
-        template: strip`
-        Args: {{this.attrs.value}} | {{@value}} | {{this.value}}
-        {{#each this.attrs.items as |item|}}
-          {{item}}
-        {{/each}}
-        {{#each @items as |item|}}
-          {{item}}
-        {{/each}}
-        {{#each this.items as |item|}}
-          {{item}}
-        {{/each}}
-      `,
-      });
+      expectDeprecation(() => {
+        this.registerComponent('foo-bar', {
+          template: strip`
+          Args: {{this.attrs.value}} | {{@value}} | {{this.value}}
+          {{#each this.attrs.items as |item|}}
+            {{item}}
+          {{/each}}
+          {{#each @items as |item|}}
+            {{item}}
+          {{/each}}
+          {{#each this.items as |item|}}
+            {{item}}
+          {{/each}}
+        `,
+        });
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs..+}} should be updated to {{@.+}}./);
 
       this.render('{{foo-bar value=this.model.value items=this.model.items}}', {
         model: {
@@ -1576,10 +1582,13 @@ moduleFor(
       }, "Using {{attrs}} to reference named arguments is not supported. {{attrs.someProp}} should be updated to {{@someProp}}. ('my-app/templates/components/with-block.hbs' @ L1:C24) ");
     }
 
+    // Perhaps change this test to `{{this.attrs.someProp.value}}` when removing the deprecation?
     ['@test block with properties on this.attrs']() {
-      this.registerComponent('with-block', {
-        template: 'In layout - someProp: {{this.attrs.someProp}} - {{yield}}',
-      });
+      expectDeprecation(() => {
+        this.registerComponent('with-block', {
+          template: 'In layout - someProp: {{this.attrs.someProp}} - {{yield}}',
+        });
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs.someProp}} should be updated to {{@someProp}}./);
 
       this.render(
         strip`
@@ -3319,16 +3328,19 @@ moduleFor(
       }, "Using {{attrs}} to reference named arguments is not supported. {{attrs.myVar}} should be updated to {{@myVar}}. ('my-app/templates/components/foo-bar.hbs' @ L1:C10) ");
     }
 
+    // Perhaps change this test to `{{this.attrs.myVar.value}}` when removing the deprecation?
     ['@test using this.attrs for positional params']() {
       let MyComponent = Component.extend();
 
-      this.registerComponent('foo-bar', {
-        ComponentClass: MyComponent.reopenClass({
-          positionalParams: ['myVar'],
-        }),
-        template:
-          'MyVar1: {{this.attrs.myVar}} {{this.myVar}} MyVar2: {{this.myVar2}} {{this.attrs.myVar2}}',
-      });
+      expectDeprecation(() => {
+        this.registerComponent('foo-bar', {
+          ComponentClass: MyComponent.reopenClass({
+            positionalParams: ['myVar'],
+          }),
+          template:
+            'MyVar1: {{this.attrs.myVar}} {{this.myVar}} MyVar2: {{this.myVar2}} {{this.attrs.myVar2}}',
+        });
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs.myVar2?}} should be updated to {{@myVar2?}}./);
 
       this.render('{{foo-bar 1 myVar2=2}}');
 

packages/ember-template-compiler/lib/plugins/assert-against-attrs.ts

@@ -1,4 +1,4 @@
-import { assert } from '@ember/debug';
+import { assert, deprecate } from '@ember/debug';
 import type { AST, ASTPlugin } from '@glimmer/syntax';
 import calculateLocationDisplay from '../system/calculate-location-display';
 import type { EmberASTPluginEnvironment } from '../types';
@@ -56,17 +56,41 @@ export default function assertAgainstAttrs(env: EmberASTPluginEnvironment): ASTP
 
       PathExpression(node: AST.PathExpression): AST.Node | void {
         if (isAttrs(node, stack[stack.length - 1]!)) {
-          let path = b.path(node.original.substring(6));
-
           assert(
-            `Using {{attrs}} to reference named arguments is not supported. {{attrs.${
-              path.original
-            }}} should be updated to {{@${path.original}}}. ${calculateLocationDisplay(
+            `Using {{attrs}} to reference named arguments is not supported. {{${
+              node.original
+            }}} should be updated to {{@${node.original.slice(6)}}}. ${calculateLocationDisplay(
+              moduleName,
+              node.loc
+            )}`
+          );
+        } else if (isThisDotAttrs(node)) {
+          // When removing this, ensure `{{this.attrs.foo}}` is left as-is, without triggering
+          // any assertions/deprecations. It's perfectly legal to reference `{{this.attrs.foo}}`
+          // in the template since it is a real property on the backing class – it will give you
+          // a `MutableCell` wrapper object, but maybe that's what you want. And in any case,
+          // there is no compelling to special case that property access.
+          deprecate(
+            `Using {{this.attrs}} to reference named arguments has been deprecated. {{${
+              node.original
+            }}} should be updated to {{@${node.original.slice(11)}}}. ${calculateLocationDisplay(
               moduleName,
               node.loc
             )}`,
-            node.this !== false
+            false,
+            {
+              id: 'attrs-arg-access',
+              url: 'https://deprecations.emberjs.com/v3.x/#toc_attrs-arg-access',
+              until: '6.0.0',
+              for: 'ember-source',
+              since: {
+                available: '3.26.0',
+                enabled: '3.26.0',
+              },
+            }
           );
+
+          return b.path(`@${node.original.slice(11)}`, node.loc);
         }
       },
     },
@@ -75,19 +99,10 @@ export default function assertAgainstAttrs(env: EmberASTPluginEnvironment): ASTP
 
 function isAttrs(node: AST.PathExpression, symbols: string[]) {
   let name = node.parts[0];
+  return node.head.type === 'VarHead' && name === 'attrs' && symbols.indexOf(name) === -1;
+}
 
-  if (name && symbols.indexOf(name) !== -1) {
-    return false;
-  }
-
-  if (name === 'attrs') {
-    if (node.this === true) {
-      node.parts.shift();
-      node.original = node.original.slice(5);
-    }
-
-    return true;
-  }
-
-  return false;
+function isThisDotAttrs(node: AST.PathExpression) {
+  let name = node.parts[0];
+  return node.head.type === 'ThisHead' && name === 'attrs';
 }

packages/ember-template-compiler/tests/plugins/assert-against-attrs-test.js

@@ -29,14 +29,26 @@ moduleFor(
       }, /Using {{attrs}} to reference named arguments is not supported. {{attrs.foo.bar}} should be updated to {{@foo.bar}}./);
     }
 
-    ['@test it does not assert against this.attrs']() {
-      this.assertTransformed(`{{this.attrs.foo}}`, `{{this.attrs.foo}}`);
-      this.assertTransformed(`{{if this.attrs.foo "foo"}}`, `{{if this.attrs.foo "foo"}}`);
-      this.assertTransformed(`{{#if this.attrs.foo}}{{/if}}`, `{{#if this.attrs.foo}}{{/if}}`);
-      this.assertTransformed(
-        `{{deeply (nested this.attrs.foo.bar)}}`,
-        `{{deeply (nested this.attrs.foo.bar)}}`
-      );
+    // When removing the deprecation, ensure `{{this.attrs.foo}}` isn't rewritten and does NOT trigger any assertions/deprecations
+    ['@test this.attrs is deprecated']() {
+      expectDeprecation(() => {
+        this.assertTransformed(`{{this.attrs.foo}}`, `{{@foo}}`);
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs.foo}} should be updated to {{@foo}}./);
+
+      expectDeprecation(() => {
+        this.assertTransformed(`{{if this.attrs.foo "foo"}}`, `{{if @foo "foo"}}`);
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs.foo}} should be updated to {{@foo}}./);
+
+      expectDeprecation(() => {
+        this.assertTransformed(`{{#if this.attrs.foo}}{{/if}}`, `{{#if @foo}}{{/if}}`);
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs.foo}} should be updated to {{@foo}}./);
+
+      expectDeprecation(() => {
+        this.assertTransformed(
+          `{{deeply (nested this.attrs.foo.bar)}}`,
+          `{{deeply (nested @foo.bar)}}`
+        );
+      }, /Using {{this.attrs}} to reference named arguments has been deprecated. {{this.attrs.foo.bar}} should be updated to {{@foo.bar}}./);
     }
   }
 );