feat: replace ESLint with oxlint across the workspace

Wire oxlint into lint-staged, ui-scripts lint, and regression-test's
lint script, replacing ESLint everywhere it ran. Remove ESLint's config
files, its now-superseded custom plugin, and dependencies that have no
remaining consumer: eslint, @eslint/js, @vitest/eslint-plugin,
eslint-config-prettier, eslint-import-resolver-node,
eslint-module-utils, eslint-plugin-compat, eslint-plugin-jsx-a11y,
eslint-plugin-notice, globals, and typescript-eslint.

eslint-plugin-react and read-package-up are kept - both are still
runtime dependencies of oxlint's jsPlugins bridge and custom rules,
respectively.

Author: joyenjoyer

eslint.config.mjs

@@ -59,7 +59,6 @@
     "@commitlint/config-conventional": "^21.2.0",
     "@emotion/cache": "^11.14.0",
     "@emotion/react": "^11.14.0",
-    "@eslint/js": "^9.39.4",
     "@instructure/browserslist-config-instui": "workspace:*",
     "@instructure/ui-babel-preset": "workspace:*",
     "@instructure/ui-scripts": "workspace:*",
@@ -72,7 +71,6 @@
     "@types/react": "18.3.26",
     "@types/react-dom": "18.3.1",
     "@vitejs/plugin-react": "^5.2.0",
-    "@vitest/eslint-plugin": "^1.6.20",
     "babel-loader": "^10.1.1",
     "babel-plugin-add-import-extension": "^1.6.0",
     "chai": "^4.4.1",
@@ -85,15 +83,7 @@
     "cz-git": "^1.13.1",
     "esbuild": "^0.28.1",
     "esbuild-loader": "^4.5.0",
-    "eslint": "^9.39.4",
-    "eslint-config-prettier": "^10.1.8",
-    "eslint-import-resolver-node": "^0.4.0",
-    "eslint-module-utils": "2.13.0",
-    "eslint-plugin-compat": "^7.0.2",
-    "eslint-plugin-jsx-a11y": "^6.10.2",
-    "eslint-plugin-notice": "^1.0.0",
     "eslint-plugin-react": "^7.37.5",
-    "globals": "^17.7.0",
     "husky": "^9.1.7",
     "jsdom": "^29.1.1",
     "lerna": "9.0.7",
@@ -103,16 +93,13 @@
     "react": "18.3.1",
     "read-package-up": "^12.0.0",
     "typescript": "6.0.3",
-    "typescript-eslint": "^8.62.1",
     "vitest": "^4.1.9",
     "webpack": "^5.107.2"
   },
   "//dependency-comments": {
     "scripts": "The '--' at the end of commands is needed so user parameters are passed forward",
     "danger": "^11.3.1 -- add this back if we use it in pr-validation.yml",
     "tar": "Lerna 8 needs tar for this fixed(?) bug: https://github.com/lerna/lerna/issues/4005",
-    "eslint-import-resolver-typescript": "^3.6.1 not supported by ESLint 9",
-    "eslint-plugin-import-x": "^3.1.0 not supported by ESLint 9",
     "@types/jest": "needed because https://github.com/testing-library/jest-dom/issues/544 recheck if fixed",
     "git-raw-commits>dargs": "Force dargs@7.0.0 (CommonJS) for git-raw-commits@3.0.0 used by lerna. pnpm hoisting was causing ESM dargs@8.1.0 to be resolved instead, breaking 'pnpm run bump' with 'TypeError: dargs is not a function'"
   },
@@ -128,7 +115,7 @@
   },
   "lint-staged": {
     "*.{js,ts,tsx}": [
-      "eslint --quiet",
+      "oxlint -c .oxlintrc.json --fix",
       "prettier --write"
     ],
     "*.{json,jsx,md,mdx,html}": [

package.json

@@ -40,7 +40,7 @@ describe('lint handler', () => {
 
   it('lints "." when no positional paths are provided', async () => {
     await lint.handler({ _: ['lint'] })
-    expect(runMock).toHaveBeenCalledWith('eslint', ['.'])
+    expect(runMock).toHaveBeenCalledWith('oxlint', ['.'])
   })
 
   it('keeps only .js, .jsx, .ts, .tsx paths', async () => {
@@ -56,23 +56,23 @@ describe('lint handler', () => {
     expect(runMock).not.toHaveBeenCalled()
   })
 
-  it('passes --fix to eslint when argv.fix is true', async () => {
+  it('passes --fix to oxlint when argv.fix is true', async () => {
     await lint.handler({ _: ['lint', 'a.ts'], fix: true })
-    expect(runMock).toHaveBeenCalledWith('eslint', ['a.ts', '--fix'])
+    expect(runMock).toHaveBeenCalledWith('oxlint', ['a.ts', '--fix'])
   })
 
   it('does not pass --fix when argv.fix is false', async () => {
     await lint.handler({ _: ['lint', 'a.ts'], fix: false })
-    expect(runMock).toHaveBeenCalledWith('eslint', ['a.ts'])
+    expect(runMock).toHaveBeenCalledWith('oxlint', ['a.ts'])
   })
 
   it('does not pass --fix when argv.fix is undefined', async () => {
     await lint.handler({ _: ['lint', 'a.ts'] })
-    expect(runMock).toHaveBeenCalledWith('eslint', ['a.ts'])
+    expect(runMock).toHaveBeenCalledWith('oxlint', ['a.ts'])
   })
 
   it('appends --fix even when linting the default "." path', async () => {
     await lint.handler({ _: ['lint'], fix: true })
-    expect(runMock).toHaveBeenCalledWith('eslint', ['.', '--fix'])
+    expect(runMock).toHaveBeenCalledWith('oxlint', ['.', '--fix'])
   })
 })

packages/ui-scripts/lib/__node_tests__/lint.test.ts

@@ -43,7 +43,7 @@ export default {
       )
     }
     if (jspaths.length) {
-      runCommandSync('eslint', argv.fix ? [...jspaths, '--fix'] : jspaths)
+      runCommandSync('oxlint', argv.fix ? [...jspaths, '--fix'] : jspaths)
     }
   }
 }

packages/ui-scripts/lib/commands/lint.ts

@@ -40,7 +40,7 @@
     "read-package-up": "^12.0.0"
   },
   "peerDependencies": {
-    "eslint": "^9",
+    "oxlint": "^1.72.0",
     "react": ">=18 <=19",
     "webpack": "^5"
   },