Modernize JavaScript build toolchain

Replace Rollup with Rolldown v1 for bundling (10-30x faster builds).
The new config lives in rolldown.config.mjs and the build script is
updated accordingly.

Replace ESLint + neostandard with Oxlint v1 for linting (50-100x faster).
The new config lives in .oxlintrc.json and is run via `pnpm lint`.
Use `args: none` on no-unused-vars to skip unused function parameters,
which serve as API documentation for callback signatures.
Rename .github/workflows/eslint.yml to lint.yml accordingly.

These choices are informed by ongoing upstream discussions about how
best to align the neostandard and Rollup ecosystems with modern
JavaScript tooling (neostandard/neostandard#350, rollup/plugins#2010).

Drop Babel — transpilation is now handled by Rolldown's built-in Oxc
transforms. The minimum browser targets are unchanged (Chrome 60+,
Firefox 60+, iOS 12+, Safari 12+).

Remove 9 unused npm devDependencies (`@babel/core`, `@babel/preset-env`,
`@rollup/plugin-babel`, `@rollup/plugin-node-resolve`, `eslint`,
`eslint-plugin-compat`, `neostandard`, `rollup`, `rollup-plugin-copy`).

Clean up .gitignore (remove stale !.babelrc negation) and update
Rakefile lint task to call the new `pnpm lint` script instead of
`pnpm eslint`.

Author: tagliala

.babelrc

@@ -1,4 +1,4 @@
-name: ESLint
+name: Lint
 
 on:
   push:
@@ -10,8 +10,8 @@ permissions:
   contents: read
 
 jobs:
-  eslint:
-    name: ESLint
+  lint:
+    name: Lint
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v7
@@ -23,4 +23,4 @@ jobs:
     - name: Install node dependencies
       run: pnpm install
     - name: Run JavaScript linter
-      run: pnpm eslint
+      run: pnpm lint

.github/workflows/eslint.yml .github/workflows/lint.yml.github/workflows/eslint.yml renamed to .github/workflows/lint.yml

@@ -17,6 +17,4 @@ test/log
 
 node_modules
 
-!.babelrc
-
 pnpm-lock.yaml

.gitignore

@@ -0,0 +1,21 @@
+{
+  "$schema": "./node_modules/oxlint/configuration_schema.json",
+  "plugins": ["eslint"],
+  "env": {
+    "browser": true
+  },
+  "globals": {
+    "QUnit": "readonly"
+  },
+  "categories": {
+    "correctness": "error",
+    "suspicious": "warn"
+  },
+  "rules": {
+    "no-undef": "error",
+    "no-unused-vars": ["warn", { "args": "none" }],
+    "eqeqeq": ["error", "smart"],
+    "no-var": "error",
+    "prefer-const": "error"
+  }
+}

.oxlintrc.json

@@ -2,10 +2,14 @@
 
 ## 25.0.0 / unreleased
 
-* [FEATURE] Breaking change: remove unused JavaScript source exports
+* [FEATURE] Breaking change: Remove unused JavaScript source exports
   - Deep imports of `src/validators/local/*` must use named exports instead of the removed default object exports, for example `import { acceptanceLocalValidator } from '@client-side-validations/client-side-validations/src/validators/local/acceptance'`
   - Remove the unused `addClass` and `removeClass` exports from `src/utils.js`
-  - Explicitly remove dead \`inputs\` and \`validate_inputs\` entries from \`ClientSideValidations.selectors\`; only \`forms\` is read by the runtime`
+  - Explicitly remove dead \`inputs\` and \`validate_inputs\` entries from \`ClientSideValidations.selectors\`; only \`forms\` is read by the runtime
+* [FEATURE] Breaking change: Replace Rollup with Rolldown v1 for bundling (10–30× faster builds)
+* [FEATURE] Breaking change: Replace ESLint + neostandard with Oxlint v1 for linting (50–100× faster)
+* [FEATURE] Breaking change: Drop Babel — transpilation handled by Rolldown's built-in Oxc transforms (minimum browser targets are unchanged: Chrome 60+, Firefox 60+, iOS 12+, Safari 12+)
+* [ENHANCEMENT] Remove 9 unused npm devDependencies (smaller install footprint)
 
 ## 24.0.0 / 2026-04-19
 * [FEATURE] Breaking change: Remove the jQuery runtime dependency and the old jQuery plugin aliases from the published JavaScript assets

CHANGELOG.md

@@ -55,7 +55,7 @@ end
 
 desc %(Lint JavaScript files)
 task :lint_javascript do
-  run_pnpm_script 'eslint'
+  run_pnpm_script 'lint'
 end
 
 desc %(Regenerate JavaScript files)