Updates to support ESLint 9.x by khawkins · Pull Request #61 · salesforce/eslint-plugin-lwc-graph-analyzer

khawkins · 2025-06-10T20:46:05Z

What does this PR do?

Updates our ESLint support to 9.x. I'll add comments inline.

khawkins · 2025-06-10T23:28:00Z

eslint.config.js

+const js = require('@eslint/js');
+const nodePlugin = require('eslint-plugin-n');
+const eslintPlugin = require('eslint-plugin-eslint-plugin');
+const tseslint = require('typescript-eslint');


Added TypeScript linting for the index.d.ts type declarations.

khawkins · 2025-06-10T23:29:21Z

eslint.config.js

+ */
+
+const js = require('@eslint/js');
+const nodePlugin = require('eslint-plugin-n');


eslint-plugin-node is a project that has apparently fallen by the wayside. So the ESLint community forked it and went with eslint-plugin-n. This project, by contrast, gets a goodly amount of attention.

khawkins · 2025-06-10T23:30:45Z

jest.config.js

 * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
 */

-'use strict';


There are going to be a lot of these to ignore, unfortunately. Apparently this isn't required for modules, and throws linting exceptions if you keep them.

khawkins · 2025-06-10T23:31:29Z

lib/configs/base-legacy.js

@@ -0,0 +1,21 @@
+/*


base.js was migrated into base-legacy.js. This is the configuration that ESLint 8.x consumers will need to use.

khawkins · 2025-06-10T23:32:24Z

lib/configs/base.js

 */

-'use strict';
+const bundleAnalyzer = require('../processor');


base.js is now the ESLint flat config, supported by ESLint 9. ESLint 9 support is now the default.

khawkins · 2025-06-10T23:33:11Z

lib/configs/recommended-legacy.js

+ * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/MIT
+ */
+
+module.exports = {


recommended-legacy.js is the same as base-legacy.js. ESLint 8.x consumers will need to use these configs.

khawkins · 2025-06-10T23:34:15Z

lib/configs/recommended.js

 */

-'use strict';
+const baseConfig = require('./base');


...and recommended.js becomes the flat config for ESLint 9.x support.

khawkins · 2025-06-10T23:35:53Z

lib/index.js

-const recommended = require('./configs/recommended');
 const LwcBundle = require('./lwc-bundle');
-
-const noGetterContainsMoreThanReturnStatement = require('./rules/no-getter-contains-more-than-return-statement');


These have all been moved into an aggregate export in rules/index.js. Makes the plugin spec easier to read.

khawkins · 2025-06-10T23:37:07Z

lib/index.js

-        recommended
+        base: require('./configs/base'),
+        recommended: require('./configs/recommended'),
+        'base-legacy': require('./configs/base-legacy'),


Both "current" and "legacy" configs are now available. Any ESLint engine >=7 will work with the plugin, as long as you use the right config.

We might need to update the readme.md to let the user now how to use legacy config in ESLint 8. For example, for ESLint 8, use

{ "extends": ["eslint:recommended", "plugin:@salesforce/lwc-graph-analyzer/recommended-legacy"] }

That's a good idea. I'll update.

khawkins · 2025-06-11T00:06:59Z

lib/processor.js

     * by the ESLint CLI, or a dummy value (__placeholder__.js) if called programatically.
     * @returns A one-dimensional flattened array of messages.
     */
-    // eslint-disable-next-line no-unused-vars


For some reason no-unused-vars no longer flags here, and honestly I can't figure out why. ¯\(ツ)/¯

khawkins · 2025-06-11T00:07:39Z

lib/rules/index.js

@@ -0,0 +1,40 @@
+module.exports = {


All the rule definitions moved in here. Keep all the clutter in one place.

khawkins · 2025-06-11T00:12:13Z

test/lib/rules/artifacts-combined-files/helper.js

+ * @param {string} blockFilename - The filename of the code block being processed
+ * @returns {boolean} True if the code block should be processed (has .js or .html extension), false otherwise
 */
-function createLinter(rulename) {


Since the options specified in here were legacy 8.x options, I just got rid of the method and added const linter = new Linter(); where it was necessary.

khawkins · 2025-06-11T00:16:05Z

test/lib/rules/artifacts-combined-files/helper.js

-    linter.defineParser('@babel/eslint-parser', babelParser);
-    linter.defineRule(rulename, lwcGraphAnalyzer.rules[rulename]);
-    return linter;
+function filterCodeBlock(blockFilename) {


It turns out this (and its use below) is important for calling Linter.verify() programmatically. Without it, ESLint will just silently drop any files coming out of preprocessing, that don't have a .js extension. So .html files were not working.

In the linter.verify(srcCode, config, { filename: testPath, filterCodeBlock }), the config already has the html file configured. If that is not enough, does that mean lgpt-core lint has the same issue?

It's not enough, and lgpt-core will have the same issue. We just hadn't run into it before, because we hadn't been working with linting the .html files. I'm going to create a work item to be able to provide those options as part of linting.

khawkins · 2025-06-11T00:17:30Z

test/lib/rules/artifacts-combined-files/helper.js


-    return linter.verify(srcCode, config, {
-        filename: testPath,
-        preprocess: lwcGraphAnalyzer.processors.bundleAnalyzer.preprocess,


This has all just been normalized to standard ESLint config, so the config returned by createLinterConfig() is sufficient to capture the proper options now.

khawkins · 2025-06-11T00:19:20Z

test/lib/rules/no-assignment-expression-assigns-value-to-member-variable.js

 const { RuleTester } = require('eslint');
 const { RULE_TESTER_CONFIG } = require('./shared');
 const lwcGraphAnalyzer = require('../../../lib/index');
-const bundleAnalyzer = lwcGraphAnalyzer.processors.bundleAnalyzer;


Starting from here, you'll see this across the rest of the test/lib/rules tests. The updates are all the same: remove the weird configuration override from 8.x where there was no other way to specify a processor, in favor of the ESLint config in shared.js, which defines it.

khawkins · 2025-06-11T00:20:22Z

test/lib/rules/shared.js

-        babelOptions: {
-            parserOpts: {
-                plugins: [['decorators', { decoratorsBeforeExport: false }]]
+    languageOptions: {


Here's the shared ESLint config update that replaces all of those test configs above.

Do we need to define the 'files' sections?

We can. It was part oversight, part the fact that there aren't other configurations that interfere with ours in a test environment. But per my previous comment, I think it would be beneficial to standardize this config in both production and test, now that we can.

haifeng-li-at-salesforce · 2025-06-11T21:34:09Z

test/lib/rules/no-assignment-expression-assigns-value-to-member-variable.js

 const lwcGraphAnalyzer = require('../../../lib/index');
-const bundleAnalyzer = lwcGraphAnalyzer.processors.bundleAnalyzer;
 const ruleTester = new RuleTester(RULE_TESTER_CONFIG);



Is this the ESLint 9 flat config?

It is an ESLint 9 flat config. But you got me thinking, now that configs are way more normalized between different scenarios (production vs. test configs, etc.) it would probably be good to have a common config, just so that we're implicitly testing our config setup as part of our testing. I'll make a change here.

haifeng-li-at-salesforce

The changes look great! The only remaining update is to the Readme.md to reflect support for both ESLint v8 and v9.

khawkins · 2025-06-16T18:01:30Z

Alright, @haifeng-li-at-salesforce let me know if you want to take another look. I updated the README with ESLint version-specific configuration instructions, and standardized the test configs to work from the base config that we ship.

Updates to support ESLint 9.x

3b187f6

khawkins requested review from a team, dbreese, maliroteh-sf and sfdctaka as code owners June 10, 2025 20:46

Updating project linting to ESLint 9

981a313

khawkins commented Jun 10, 2025

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khawkins commented Jun 11, 2025

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haifeng-li-at-salesforce reviewed Jun 11, 2025

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haifeng-li-at-salesforce approved these changes Jun 11, 2025

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khawkins added 2 commits June 16, 2025 10:20

Adding ESLint version-specific configuration docs

cfa1bed

Standardizing base flat config in tests

2d88c0c

khawkins merged commit 6e8ec0d into salesforce:main Jun 17, 2025
7 checks passed

khawkins deleted the eslint_9 branch June 17, 2025 21:36

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khawkins commented Jun 10, 2025

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khawkins Jun 11, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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khawkins commented Jun 16, 2025

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khawkins Jun 11, 2025 •

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