Migrate from ESLint to Oxlint for faster linting (#653)

OskarDamkjaer · claude · web-flow · commit 58d31f8c07a7 · 2026-02-27T16:53:58.000+01:00
* Migrate ESLint to Oxlint with @nkzw/oxlint-config Replace ESLint 8 + @typescript-eslint with oxlint + oxlint-tsgolint for type-aware linting. Uses @nkzw/oxlint-config as the shared base config with conservative rule overrides to preserve the original lint surface (no new violations requiring codebase changes). - Add: oxlint, oxlint-tsgolint, @nkzw/oxlint-config and required JS plugins - Remove: eslint, @typescript-eslint/eslint-plugin, @typescript-eslint/parser, eslint-config-prettier - Create oxlint.config.ts with calibrated overrides that disable @nkzw rules beyond the original ESLint scope (perfectionist sorting, unicorn stylistic rules, react-hooks-js extras, etc.) - Disable unused-imports/no-unused-imports due to @typescript-eslint compat crash in oxlint's JS plugin runner on TSMappedType - Update package.json lint scripts: eslint → oxlint --type-aware - Update .lintstagedrc.json: eslint --fix → oxlint --fix - Update CI workflow job name - Delete .eslintrc.js and .eslintignore https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Simplify oxlint config: drop @nkzw/oxlint-config and all JS plugins Use oxlint + oxlint-tsgolint with standard defaults only. No third-party plugin layer needed — oxlint's built-in rules cover the correctness and TypeScript-aware checks we care about. - Remove: @nkzw/oxlint-config, @nkzw/eslint-plugin, eslint-plugin-no-only-tests, eslint-plugin-perfectionist, eslint-plugin-react-hooks, eslint-plugin-unused-imports - Simplify oxlint.config.ts to just ignorePatterns + typescript plugin + the three custom rules from original ESLint (no-console, no-var-requires off, unbound-method off) Result: pnpm lint exits 0 (194 warnings from tsgolint type-aware defaults, 0 errors) https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Add --max-warnings 0; fix/suppress all warnings for clean lint - Remove dead overrides (no-var-requires, unbound-method had 0 violations) - Disable no-redundant-type-constituents and no-duplicate-type-constituents: systematic false positives from neo4j-driver types using `any` internally, causing cascading type issues in unions across ~40 files - Add --max-warnings 0 to lint script for strict mode going forward - Fix no-unused-vars: 15 catch bindings → `catch { }` (unused params) - Fix no-unused-expressions: convert ternary-as-statement to if/else, fix comma-assignment syntax, add missing `return`, remove stray `1;` - Add file-level oxlint-disable for no-misused-spread in test file (intentional plain-object spreads of class instances for comparison) - Fix require-array-sort-compare: .sort() → .sort((a, b) => a.localeCompare(b)) - Add inline disable for restrict-template-expressions and no-meaningless-void-operator (type-cascade false positive / preserve behavior) Result: pnpm lint exits 0 with 0 warnings and 0 errors https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Move no-misused-spread to config-level off, remove file disable comment https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Restore unbound-method: off for Playwright mount fixture false positives The `mount` parameter in Playwright e2e tests is a test fixture destructured from the test context, not a class method — oxlint incorrectly flags it as an unbound method reference. This restores the suppression that was mistakenly removed in the previous commit. https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Replace vscode-eslint recommendation with oxc-vscode; clean up tsconfig.node - Swap dbaeumer.vscode-eslint for oxc.oxc-vscode in .vscode/extensions.json - Remove .eslintrc.js from tsconfig.node.json include (file no longer exists) https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Remove unnecessary playwright/index.tsx from oxlint ignorePatterns The file produces no lint violations so it does not need to be ignored. https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Remove unnecessary ignore for simple-match.js; fix no-unused-vars Prefix unused fixture variables with _ instead of suppressing the file in oxlint ignorePatterns. https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Restore original variable names in simple-match.js, suppress lint via comment Use /* eslint-disable no-unused-vars */ (matching the pattern in simple-match.ts) to avoid invalidating variable names that are part of the textmate snapshot. https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Revert simple-match.js to original, add textmate fixtures to oxlint ignore The textmate fixture files are test data for snapshot-based syntax highlighting tests. They intentionally contain unused variables and other patterns that trigger lint rules. Ignoring the entire fixtures directory is more robust than suppressing individual rules per file. https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Match lint-staged flags to pnpm lint: --type-aware, --max-warnings 0, *.js Align the pre-commit hook with the full lint script by adding --type-aware and --max-warnings 0 to the oxlint call, and extending coverage to *.js files so the same rules apply on commit as in CI. https://claude.ai/code/session_01JZoXnsCz9YCM7SyHxfqPEH * Fix oxfmt formatting in oxlint.config.ts Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> --------- Co-authored-by: Claude <noreply@anthropic.com>
diff --git a/.eslintignore b/.eslintignore
diff --git a/.eslintrc.js b/.eslintrc.js
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
@@ -28,7 +28,7 @@ jobs:
           (git diff-index --name-status HEAD | grep "cypher.json" && (echo "Run pnpm build and commit an up to date cypher.json file please" && exit 1)) || echo "\n\nTextMate grammar is up to date"
 
   lint-and-format:
-    name: Run eslint and check formatting
+    name: Run oxlint and check formatting
     needs: build
     runs-on: ubuntu-latest
     steps:
diff --git a/.lintstagedrc.json b/.lintstagedrc.json
@@ -1,4 +1,5 @@
 {
-  "*.ts": ["oxfmt", "eslint --fix --max-warnings 0"],
+  "*.ts": ["oxfmt", "oxlint --fix --type-aware --max-warnings 0"],
+  "*.js": ["oxlint --fix --type-aware --max-warnings 0"],
   "*.json": ["oxfmt"]
 }
diff --git a/.vscode/extensions.json b/.vscode/extensions.json
@@ -2,7 +2,6 @@
   "recommendations": [
     "vitest.explorer",
     "oxc.oxc-vscode",
-    "dbaeumer.vscode-eslint",
     "bradlc.vscode-tailwindcss"
   ]
 }
diff --git a/oxlint.config.ts b/oxlint.config.ts
@@ -0,0 +1,21 @@
+import { defineConfig } from 'oxlint';
+
+export default defineConfig({
+  ignorePatterns: [
+    'semanticAnalysis.js',
+    'vendor/**',
+    '**/fixtures/textmate/**',
+  ],
+  plugins: ['typescript'],
+  rules: {
+    'no-console': ['error', { allow: ['warn', 'error'] }],
+    // False positive: Playwright's `mount` fixture is destructured from the
+    // test context object, not from a class, so it is not an unbound method.
+    '@typescript-eslint/unbound-method': 'off',
+    // These rules produce systematic false positives because neo4j-driver
+    // types use `any` internally, causing cascading type issues in unions.
+    '@typescript-eslint/no-redundant-type-constituents': 'off',
+    '@typescript-eslint/no-duplicate-type-constituents': 'off',
+    '@typescript-eslint/no-misused-spread': 'off',
+  },
+});
diff --git a/package.json b/package.json
@@ -22,7 +22,7 @@
     "test": "pnpm --recursive --parallel test",
     "test:e2e": "pnpm --recursive test:e2e",
     "test:formattingIntegrity": "tsx ./packages/language-support/src/tests/formatting/verification/verificationCheck.ts",
-    "lint": "eslint . --ext .ts,.tsx,.js,.mts",
+    "lint": "oxlint --type-aware --max-warnings 0",
     "lint-fix": "pnpm lint --fix",
     "format": "oxfmt",
     "format:check": "oxfmt --check",
@@ -31,16 +31,14 @@
   "devDependencies": {
     "@changesets/cli": "^2.28.1",
     "@types/node": "^24.10.1",
-    "@typescript-eslint/eslint-plugin": "^7.8.0",
-    "@typescript-eslint/parser": "^7.0.0",
     "concurrently": "^8.2.1",
     "cross-env": "^7.0.3",
     "esbuild": "^0.27.1",
-    "eslint": "^8.32.0",
-    "eslint-config-prettier": "^8.6.0",
     "husky": "^8.0.0",
     "lint-staged": "^16.1.2",
     "oxfmt": "^0.35.0",
+    "oxlint": "^1.50.0",
+    "oxlint-tsgolint": "^0.14.2",
     "rimraf": "^6.0.1",
     "semver": "^7.6.1",
     "ts-node": "10.9.1",
diff --git a/packages/language-server/src/server.ts b/packages/language-server/src/server.ts
@@ -97,7 +97,7 @@ class SymbolFetcher {
               }),
           );
         }
-      } catch (e) {
+      } catch {
         //eslint-disable-next-line
         console.log('Symbol table calculation failed');
       }
@@ -245,6 +245,7 @@ connection.onNotification(
   }) => {
     neo4jSchemaPoller.events.once(
       'schemaFetched',
+      // oxlint-disable-next-line typescript-eslint/no-meaningless-void-operator
       void symbolFetcher.queueSymbolJob(
         params.query,
         params.uri,
diff --git a/packages/language-support/src/autocompletion/schemaBasedCompletions.ts b/packages/language-support/src/autocompletion/schemaBasedCompletions.ts
@@ -57,7 +57,7 @@ export function getShortPathCompletions(
       return [];
     }
     cnfTree = convertToCNF(treeWithRewrittenAnys);
-  } catch (e) {
+  } catch {
     return [];
   }
   const { inLabels, outLabels } = walkCNFTree(
@@ -119,7 +119,7 @@ export function getPathCompletions(
       return [];
     }
     cnfTree = convertToCNF(treeWithRewrittenAnys);
-  } catch (e) {
+  } catch {
     return [];
   }
   const { inLabels: inRelTypes, outLabels: outRelTypes } = walkCNFTree(
@@ -393,7 +393,7 @@ export function completeNodeLabel(
           return [];
         }
         cnfTree = convertToCNF(treeWithRewrittenAnys);
-      } catch (e) {
+      } catch {
         return allLabelCompletions(dbSchema);
       }
       let allIncomingLabels = new Set<string>();
@@ -490,7 +490,7 @@ export function completeRelationshipType(
           return [];
         }
         cnfTree = convertToCNF(treeWithRewrittenAnys);
-      } catch (e) {
+      } catch {
         return [];
       }
       let allIncomingLabels = new Set<string>();
diff --git a/packages/language-support/src/syntaxValidation/completionCoreErrors.ts b/packages/language-support/src/syntaxValidation/completionCoreErrors.ts
@@ -125,7 +125,7 @@ export function completionCoreErrormessage(
 
   const keywordCandidates = tokenCandidates
     .filter((v) => keywordNames.has(v))
-    .sort();
+    .sort((a, b) => a.localeCompare(b));
   const nonKeywordCandidates = tokenCandidates.filter(
     (v) => !keywordNames.has(v),
   );
diff --git a/packages/language-support/src/syntaxValidation/semanticAnalysisWrapper.ts b/packages/language-support/src/syntaxValidation/semanticAnalysisWrapper.ts
@@ -151,7 +151,7 @@ export function wrappedSemanticAnalysis(
       ),
       symbolTable: copySymbolTable(symbolTable),
     };
-  } catch (e) {
+  } catch {
     /* Ignores exceptions if they happen calling the semantic analysis. Should not happen but this is just defensive in case it did */
     return { errors: [], notifications: [], symbolTable: [] };
   }
diff --git a/packages/lint-worker/src/helpers.ts b/packages/lint-worker/src/helpers.ts
@@ -93,7 +93,7 @@ export async function getTaggedRegistryVersions(): Promise<NpmRelease[]> {
     }
 
     return taggedVersions;
-  } catch (error) {
+  } catch {
     return [];
   }
 }
diff --git a/packages/query-tools/src/data-transforms/record-to-string.ts b/packages/query-tools/src/data-transforms/record-to-string.ts
@@ -70,6 +70,7 @@ export function propertyToString(
 
   if (typeof property === 'string') {
     if (quoteStrings) {
+      // oxlint-disable-next-line typescript-eslint/restrict-template-expressions
       return `"${property}"`;
     }
     return property;
diff --git a/packages/query-tools/src/schemaPoller.ts b/packages/query-tools/src/schemaPoller.ts
@@ -168,7 +168,7 @@ export class Neo4jSchemaPoller {
         );
         return ['5', '25'];
       }
-    } catch (e) {
+    } catch {
       return ['5'];
     }
 
diff --git a/packages/react-codemirror/src/CypherEditor.tsx b/packages/react-codemirror/src/CypherEditor.tsx
@@ -190,7 +190,7 @@ const format = (view: EditorView): void => {
       },
       selection: { anchor: newCursorPos },
     });
-  } catch (error) {
+  } catch {
     // Formatting failed, likely because of a syntax error
   }
 };
diff --git a/packages/react-codemirror/src/e2e_tests/signatureHelp.spec.tsx b/packages/react-codemirror/src/e2e_tests/signatureHelp.spec.tsx
@@ -263,7 +263,6 @@ test('Signature help only shows the description past the last argument', async (
       autofocus={true}
     />,
   );
-  1;
 
   const tooltip = page.locator('.cm-signature-help-panel');
 
diff --git a/packages/react-codemirror/src/lang-cypher/utils.ts b/packages/react-codemirror/src/lang-cypher/utils.ts
@@ -2,7 +2,7 @@ import { MarkupContent } from 'vscode-languageserver-types';
 
 export function getDocString(result: string | MarkupContent): string {
   if (MarkupContent.is(result)) {
-    result.value;
+    return result.value;
   } else {
     return result;
   }
diff --git a/packages/vscode-extension/src/connectionService.ts b/packages/vscode-extension/src/connectionService.ts
@@ -294,9 +294,11 @@ export async function establishPersistentConnectionToSchemaPoller(
     connectionSettings.database,
   );
 
-  result.success
-    ? attachSchemaPollerConnectionEventListeners()
-    : attachSchemaPollerConnectionFailedEventListeners();
+  if (result.success) {
+    attachSchemaPollerConnectionEventListeners();
+  } else {
+    attachSchemaPollerConnectionFailedEventListeners();
+  }
 
   return result;
 }
@@ -416,9 +418,11 @@ async function connectToDatabaseAndNotifyLanguageClient(
       ? 'error'
       : 'inactive';
 
-  result.success
-    ? await sendNotificationToLanguageClient('connectionUpdated', settings)
-    : await sendNotificationToLanguageClient('connectionDisconnected');
+  if (result.success) {
+    await sendNotificationToLanguageClient('connectionUpdated', settings);
+  } else {
+    await sendNotificationToLanguageClient('connectionDisconnected');
+  }
 
   // Note the e2e tests are always going to be on an older neo4j version (a docker container)
   // We want for all of the tests to run with the latest version of the linter,
diff --git a/packages/vscode-extension/src/linterService.ts b/packages/vscode-extension/src/linterService.ts
@@ -18,7 +18,7 @@ export async function getFilesInExtensionStorage(): Promise<string[]> {
     return entries
       .filter(([, fileType]) => fileType === vscode.FileType.File)
       .map(([name]) => name);
-  } catch (err) {
+  } catch {
     void vscode.window.showErrorMessage(
       CONSTANTS.MESSAGES.GLOBALSTORAGE_READ_FAILED,
     );
@@ -104,7 +104,7 @@ export async function downloadLintWorker(
     });
     await vscode.workspace.fs.delete(newFolderUri, { recursive: true });
     return { success: true, fileName: fileName };
-  } catch (error) {
+  } catch {
     void vscode.window.showErrorMessage(
       CONSTANTS.MESSAGES.LINTER_DOWNLOAD_FAILED,
     );
diff --git a/packages/vscode-extension/src/linterSwitching.ts b/packages/vscode-extension/src/linterSwitching.ts
@@ -20,7 +20,7 @@ export async function fileExists(fileUri: vscode.Uri): Promise<boolean> {
   try {
     await vscode.workspace.fs.stat(fileUri);
     return true;
-  } catch (e) {
+  } catch {
     return false;
   }
 }
@@ -99,7 +99,7 @@ export async function switchToLinter(
         }
       }
     }
-  } catch (e) {
+  } catch {
     // In case of error use default linter (i.e. the one included with the language server)
     await switchWorkerOnLanguageServer();
   }
diff --git a/packages/vscode-extension/src/registrationService.ts b/packages/vscode-extension/src/registrationService.ts
@@ -51,7 +51,7 @@ export function registerDisposables(): Disposable[] {
       await commands.executeCommand('neo4jQueryVisualization.open', {
         preserveFocus: true,
       });
-    } catch (e) {
+    } catch {
       /* no-op */
       //If a user (or a test framework) has an old version of vscode, <webview>.open won't exist
       //A user can still open the webview manually, so we prefer not to remove focus from the editor
diff --git a/packages/vscode-extension/src/uiUtils.ts b/packages/vscode-extension/src/uiUtils.ts
@@ -73,11 +73,13 @@ export function displayMessageForSwitchDatabaseResult(
   database: string,
   result: ConnnectionResult,
 ): void {
-  result.success
-    ? void window.showInformationMessage(
-        `${CONSTANTS.MESSAGES.SUCCESSFULLY_SWITCHED_DATABASE_MESSAGE} '${database}'.`,
-      )
-    : void window.showErrorMessage(
-        `${CONSTANTS.MESSAGES.ERROR_SWITCHING_DATABASE_MESSAGE} '${database}'. ${result.error?.message}. ${result.error?.friendlyMessage}.`,
-      );
+  if (result.success) {
+    void window.showInformationMessage(
+      `${CONSTANTS.MESSAGES.SUCCESSFULLY_SWITCHED_DATABASE_MESSAGE} '${database}'.`,
+    );
+  } else {
+    void window.showErrorMessage(
+      `${CONSTANTS.MESSAGES.ERROR_SWITCHING_DATABASE_MESSAGE} '${database}'. ${result.error?.message}. ${result.error?.friendlyMessage}.`,
+    );
+  }
 }
diff --git a/packages/vscode-extension/src/webviews/queryResults/queryDetailsProvider.ts b/packages/vscode-extension/src/webviews/queryResults/queryDetailsProvider.ts
@@ -73,7 +73,9 @@ export class Neo4jQueryDetailsProvider implements WebviewViewProvider {
   }
 
   async executeStatements(statements: string[]) {
-    this.view ?? (await this.viewReadyPromise);
+    if (!this.view) {
+      await this.viewReadyPromise;
+    }
     const webview = this.view.webview;
 
     const message: QueryResultsMessage = {
diff --git a/packages/vscode-extension/tests/mocks/inMemoryMemento.ts b/packages/vscode-extension/tests/mocks/inMemoryMemento.ts
@@ -19,7 +19,5 @@ export class InMemoryMemento implements Memento {
     return Object.keys(this._storage);
   }
 
-  setKeysForSync(keys: string[]): void {
-    keys;
-  }
+  setKeysForSync(_keys: string[]): void {}
 }
diff --git a/packages/vscode-extension/tests/runApiAndUnitTests.ts b/packages/vscode-extension/tests/runApiAndUnitTests.ts
@@ -44,7 +44,7 @@ async function main() {
         DEBUG_VSCODE_TESTS: process.env.DEBUG_VSCODE_TESTS,
       },
     });
-  } catch (err) {
+  } catch {
     console.error('Failed to run integration tests');
     process.exit(1);
   } finally {
diff --git a/packages/vscode-extension/tests/testRunnerDebug.ts b/packages/vscode-extension/tests/testRunnerDebug.ts
@@ -15,10 +15,10 @@ export async function run(): Promise<void> {
       },
     }),
   ]);
-  ((process.env.NEO4J_5_PORT = neo4j5Instance.getMappedPort(7687).toString()),
-    (process.env.NEO4J_2025_PORT = neo4j2025Instance
-      .getMappedPort(7687)
-      .toString()),
-    (process.env.DEBUG_VSCODE_TESTS = 'true'));
+  process.env.NEO4J_5_PORT = neo4j5Instance.getMappedPort(7687).toString();
+  process.env.NEO4J_2025_PORT = neo4j2025Instance
+    .getMappedPort(7687)
+    .toString();
+  process.env.DEBUG_VSCODE_TESTS = 'true';
   return testRunner();
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
diff --git a/tsconfig.node.json b/tsconfig.node.json

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,5 @@`
`1`	`1`	`{`
`2`		`- "*.ts": ["oxfmt", "eslint --fix --max-warnings 0"],`
	`2`	`+ "*.ts": ["oxfmt", "oxlint --fix --type-aware --max-warnings 0"],`
	`3`	`+ "*.js": ["oxlint --fix --type-aware --max-warnings 0"],`
`3`	`4`	`"*.json": ["oxfmt"]`
`4`	`5`	`}`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,6 @@`
`2`	`2`	`"recommendations": [`
`3`	`3`	`"vitest.explorer",`
`4`	`4`	`"oxc.oxc-vscode",`
`5`		`- "dbaeumer.vscode-eslint",`
`6`	`5`	`"bradlc.vscode-tailwindcss"`
`7`	`6`	`]`
`8`	`7`	`}`
Original file line number	Diff line number	Diff line change
`@@ -57,7 +57,7 @@ export function getShortPathCompletions(`
`57`	`57`	`return [];`
`58`	`58`	`}`
`59`	`59`	`cnfTree = convertToCNF(treeWithRewrittenAnys);`
`60`		`- } catch (e) {`
	`60`	`+ } catch {`
`61`	`61`	`return [];`
`62`	`62`	`}`
`63`	`63`	`const { inLabels, outLabels } = walkCNFTree(`
`@@ -119,7 +119,7 @@ export function getPathCompletions(`
`119`	`119`	`return [];`
`120`	`120`	`}`
`121`	`121`	`cnfTree = convertToCNF(treeWithRewrittenAnys);`
`122`		`- } catch (e) {`
	`122`	`+ } catch {`
`123`	`123`	`return [];`
`124`	`124`	`}`
`125`	`125`	`const { inLabels: inRelTypes, outLabels: outRelTypes } = walkCNFTree(`
`@@ -393,7 +393,7 @@ export function completeNodeLabel(`
`393`	`393`	`return [];`
`394`	`394`	`}`
`395`	`395`	`cnfTree = convertToCNF(treeWithRewrittenAnys);`
`396`		`- } catch (e) {`
	`396`	`+ } catch {`
`397`	`397`	`return allLabelCompletions(dbSchema);`
`398`	`398`	`}`
`399`	`399`	`let allIncomingLabels = new Set<string>();`
`@@ -490,7 +490,7 @@ export function completeRelationshipType(`
`490`	`490`	`return [];`
`491`	`491`	`}`
`492`	`492`	`cnfTree = convertToCNF(treeWithRewrittenAnys);`
`493`		`- } catch (e) {`
	`493`	`+ } catch {`
`494`	`494`	`return [];`
`495`	`495`	`}`
`496`	`496`	`let allIncomingLabels = new Set<string>();`