chore: enable no-attributes-during-construction

package.json

@@ -17,7 +17,7 @@
     "test": "mocha"
   },
   "dependencies": {
-    "@lwc/eslint-plugin-lwc": "~0.11.0",
+    "@lwc/eslint-plugin-lwc": "~0.12.0",
     "babel-eslint": "~10.1.0",
     "eslint-plugin-import": "~2.22.1",
     "eslint-plugin-jest": "~23.8.2",

recommended.js

@@ -104,6 +104,7 @@ module.exports = {
         // LWC specific rules
         '@lwc/lwc/no-api-reassignments': 'error',
         '@lwc/lwc/no-async-operation': 'error',
+        '@lwc/lwc/no-attributes-during-construction': 'error',
         '@lwc/lwc/no-document-query': 'error',
         '@lwc/lwc/no-dupe-class-members': 'error',
         '@lwc/lwc/no-inner-html': 'error',

test/recommended.js

@@ -35,8 +35,8 @@ describe('recommended config', () => {
         const report = cli.executeOnText('document.querySelectorAll("a")');
 
         const { messages } = report.results[0];
-        assert.equal(messages.length, 1);
-        assert.equal(messages[0].ruleId, '@lwc/lwc/no-document-query');
+        assert.strictEqual(messages.length, 1);
+        assert.strictEqual(messages[0].ruleId, '@lwc/lwc/no-document-query');
     });
 
     it('should forbid mixing uppercase and underscore characters in public properties', () => {
@@ -50,8 +50,8 @@ describe('recommended config', () => {
         `);
 
         const { messages } = report.results[0];
-        assert.equal(messages.length, 1);
-        assert.equal(messages[0].ruleId, '@lwc/lwc/valid-api');
+        assert.strictEqual(messages.length, 1);
+        assert.strictEqual(messages[0].ruleId, '@lwc/lwc/valid-api');
     });
 
     it('should suggest usage of CustomEvent over Event constructor', () => {
@@ -60,8 +60,8 @@ describe('recommended config', () => {
         const report = cli.executeOnText(`dispatchEvent(new Event('test'));`);
 
         const { messages } = report.results[0];
-        assert.equal(messages.length, 1);
-        assert.equal(messages[0].ruleId, '@lwc/lwc/prefer-custom-event');
+        assert.strictEqual(messages.length, 1);
+        assert.strictEqual(messages[0].ruleId, '@lwc/lwc/prefer-custom-event');
     });
 
     it('should forbid duplicate class members', () => {
@@ -72,15 +72,34 @@ describe('recommended config', () => {
 
             export default class App extends LightningElement {
                 @api foo = 1;
-            
+
                 set foo(value) { this._foo = value }
                 get foo() { return this._foo; }
             }
         `);
 
         const { messages } = report.results[0];
-        assert.equal(messages.length, 2);
-        assert.equal(messages[0].ruleId, '@lwc/lwc/no-dupe-class-members');
-        assert.equal(messages[1].ruleId, '@lwc/lwc/no-dupe-class-members');
+        assert.strictEqual(messages.length, 2);
+        assert.strictEqual(messages[0].ruleId, '@lwc/lwc/no-dupe-class-members');
+        assert.strictEqual(messages[1].ruleId, '@lwc/lwc/no-dupe-class-members');
+    });
+
+    it('should prevent attributes set during construction', () => {
+        const cli = getCliEngineWithRecommendedRules();
+
+        const report = cli.executeOnText(`
+            import { LightningElement } from 'lwc';
+
+            export default class App extends LightningElement {
+                constructor() {
+                    super();
+                    this.tabIndex = '-1';
+                }
+            }
+        `);
+
+        const { messages } = report.results[0];
+        assert.strictEqual(messages.length, 1);
+        assert.strictEqual(messages[0].ruleId, '@lwc/lwc/no-attributes-during-construction');
     });
 });

yarn.lock

@@ -146,10 +146,10 @@
     minimatch "^3.0.4"
     strip-json-comments "^3.1.1"
 
-"@lwc/eslint-plugin-lwc@~0.11.0":
-  version "0.11.0"
-  resolved "https://registry.yarnpkg.com/@lwc/eslint-plugin-lwc/-/eslint-plugin-lwc-0.11.0.tgz#1c69cc673b9798e04e87ececb8529b93eb2215b1"
-  integrity sha512-wJOD4XWOH91GaZfypMSKfEeMXqMfvKdsb2gSJ/9FEwJVlziKg1aagtRYJh2ln3DyEZV33tBC/p/dWzIeiwa1tg==
+"@lwc/eslint-plugin-lwc@~0.12.0":
+  version "0.12.0"
+  resolved "https://registry.yarnpkg.com/@lwc/eslint-plugin-lwc/-/eslint-plugin-lwc-0.12.0.tgz#4065c2e9c72f4133f2e6dca5a87ca613b35a4e1d"
+  integrity sha512-p8PacTcCNg+Txgu7P+sDaLKAs1S/LyKWvbBiE3lZByGkahveISX7VARt8W+bCxUTERoXzoOPDxa7uGmawEfmXQ==
   dependencies:
     minimatch "^3.0.4"