Upgrade ESLint to v9 (#29451)

Just upgrade convex for now, plan to hit the rest later.

Upgrade ESLint to v9

GitOrigin-RevId: 953103ffa088a685b19e2ef74a714ce381e571de

eslint.config.mjs

@@ -0,0 +1,176 @@
+// @ts-check
+
+import tseslint from "typescript-eslint";
+import reactHooksPlugin from "eslint-plugin-react-hooks";
+import reactPlugin from "eslint-plugin-react";
+import vitest from "eslint-plugin-vitest";
+import { fixupPluginRules } from "@eslint/compat";
+import globals from "globals";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import js from "@eslint/js";
+import { FlatCompat } from "@eslint/eslintrc";
+import eslintConfigPrettier from "eslint-config-prettier";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all,
+});
+
+export default [
+  {
+    ignores: [
+      "**/node_modules",
+      "**/dist",
+      "tmpDist*",
+      "**/tmpPackage*",
+      "**/custom-vitest-environment.ts",
+      // TODO use a separate config for files that doesn't use TypeScript
+      "**/*.js",
+      "vitest.config.js",
+      "scripts",
+      ".prettierrc.js",
+      "eslint.config.mjs",
+      "jest.config.mjs",
+    ],
+  },
+  ...compat.plugins("require-extensions"),
+  ...compat.extends("plugin:require-extensions/recommended"),
+  js.configs.recommended,
+  {
+    files: ["**/*.js", "**/*.jsx", "**/*ts", "**/*.tsx"],
+    plugins: {
+      "@typescript-eslint": tseslint.plugin,
+      react: reactPlugin,
+      "react-hooks": fixupPluginRules(reactHooksPlugin),
+      vitest,
+    },
+
+    languageOptions: {
+      globals: {
+        ...globals.amd,
+        ...globals.browser,
+        ...globals.node,
+      },
+
+      parser: tseslint.parser,
+      ecmaVersion: 2022,
+      sourceType: "module",
+
+      parserOptions: {
+        project: ["./tsconfig.json"],
+        tsconfigRootDir: ".",
+      },
+    },
+
+    rules: {
+      ...reactHooksPlugin.configs.recommended.rules,
+      "no-debugger": "error",
+      // any is terrible but we use it a lot (even in our public code).
+      "@typescript-eslint/no-explicit-any": "off",
+      // asserting that values aren't null is risky but useful.
+      "@typescript-eslint/no-non-null-assertion": "off",
+      // Warn against interpolating objects
+      "@typescript-eslint/restrict-template-expressions": "error",
+
+      "no-redeclare": "off", // breaks for overloads
+      "@typescript-eslint/no-redeclare": "error",
+
+      "no-undef": "off",
+
+      // allow (_arg: number) => {}
+      "no-unused-vars": "off",
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        {
+          argsIgnorePattern: "^_",
+          varsIgnorePattern: "^_",
+        },
+      ],
+
+      "react-hooks/rules-of-hooks": "error",
+      "react-hooks/exhaustive-deps": "warn",
+
+      // If you add rules here, make sure to add it to subdir eslintrc files as well!
+      "no-restricted-syntax": [
+        "error",
+        {
+          // From https://github.com/typescript-eslint/typescript-eslint/issues/1391#issuecomment-1124154589
+          // Prefer `private` ts keyword to `#private` private methods
+          selector:
+            ":matches(PropertyDefinition, MethodDefinition) > PrivateIdentifier.key",
+          message: "Use `private` instead",
+        },
+      ],
+
+      // Makes it harder to accidentally fire off a promise without waiting for it.
+      "@typescript-eslint/no-floating-promises": "error",
+
+      // Since `const x = <number>foo;` syntax is ambiguous with JSX syntax some tools don't support it.
+      // In particular we need this for depcheck https://github.com/depcheck/depcheck/issues/585
+      "@typescript-eslint/consistent-type-assertions": [
+        "error",
+        {
+          assertionStyle: "as",
+        },
+      ],
+
+      eqeqeq: ["error", "always"],
+
+      // vitest (manually enabled until we can upgrade eslint)
+      "vitest/no-focused-tests": [
+        "error",
+        {
+          fixable: false,
+        },
+      ],
+    },
+  },
+  {
+    name: "CLI-specific",
+    files: ["src/cli/**/*.ts", "src/bundler/**/*.ts"],
+    ignores: ["**/*.test.ts"],
+    rules: {
+      "no-restricted-imports": [
+        "warn",
+        {
+          patterns: [
+            {
+              group: ["fs", "node:fs"],
+              message:
+                "Use a `Filesystem` implementation like `nodeFs` instead of Node's 'fs' package directly.",
+            },
+            {
+              group: ["fs/promises", "node:fs/promises"],
+              message:
+                "Use a `Filesystem` implementation like `nodeFs` instead of Node's 'fs/promises' package directly. Additionally, use synchronous filesystem IO within our CLI.",
+            },
+          ],
+        },
+      ],
+      "no-restricted-syntax": [
+        "error",
+        {
+          selector:
+            ":matches(PropertyDefinition, MethodDefinition) > PrivateIdentifier.key",
+          message: "Use `private` instead",
+        },
+        {
+          selector: "ThrowStatement",
+          message:
+            "Don't use `throw` if this is a developer-facing error message and this code could be called by `npx convex dev`. Instead use `ctx.crash`.",
+        },
+        // TODO: fix to allow process.exit(0) but not process.exit(1)
+        // {
+        //   message: "Use flushAndExit from convex/src/cli/utils.ts instead of process.exit so that Sentry gets flushed.",
+        //   selector: "CallExpression[callee.object.name='process'][callee.property.name='exit'][callee.value=1]"
+        // }
+      ],
+      "no-throw-literal": ["error"],
+    },
+  },
+  eslintConfigPrettier,
+];

package.json

@@ -138,9 +138,9 @@
     "build": "python3 scripts/build.py 2>&1",
     "bundle-server": "node scripts/bundle-server.mjs",
     "clean": "shx rm -rf dist tmpDist*",
-    "lint": "eslint . --ext .js,.jsx,.ts,.tsx",
+    "lint": "eslint .",
     "format": "prettier -w . && eslint --fix .",
-    "format-check": "prettier -c . && eslint . --ext .js,.jsx,.ts,.tsx",
+    "format-check": "prettier -c . && eslint .",
     "prepare": "npm run build",
     "prepack": "node scripts/prepack.mjs",
     "postpack": "node scripts/postpack.mjs",
@@ -164,7 +164,8 @@
   "dependencies": {
     "esbuild": "0.23.0",
     "jwt-decode": "^3.1.2",
-    "prettier": "3.2.5"
+    "prettier": "3.2.5",
+    "globals": "~15.9.0"
   },
   "peerDependencies": {
     "@auth0/auth0-react": "^2.0.1",
@@ -196,12 +197,16 @@
     "@babel/types": "7.24.0",
     "@clerk/clerk-react": "4.18.0",
     "@commander-js/extra-typings": "^11.1.0",
+    "@eslint/compat": "~1.1.1",
+    "@eslint/eslintrc": "~3.1.0",
+    "@eslint/js": "~9.9.1",
     "@sentry/node": "^7.23.0",
     "@sentry/tracing": "^7.23.0",
     "@swc/core": "1.3.107",
     "@testing-library/react": "~14.0.0",
     "@types/adm-zip": "^0.5.5",
     "@types/deep-equal": "1.0.1",
+    "@types/detect-port": "~1.3.5",
     "@types/http-proxy": "~1.17.9",
     "@types/inquirer": "^8.2.0",
     "@types/jwt-encode": "~1.0.0",
@@ -210,8 +215,6 @@
     "@types/react-dom": "^18.0.0",
     "@types/semver": "^7.3.13",
     "@types/ws": "^8.5.3",
-    "@typescript-eslint/eslint-plugin": "^6.7.4",
-    "@typescript-eslint/parser": "^6.7.4",
     "adm-zip": "^0.5.10",
     "bufferutil": "^4.0.7",
     "chalk": "4",
@@ -226,7 +229,7 @@
     "envfile": "6.18.0",
     "esbuild": "0.23.0",
     "esbuild-plugin-external-global": "~1.0.1",
-    "eslint": "^8.29.0",
+    "eslint": "9",
     "eslint-config-prettier": "^8.5.0",
     "eslint-plugin-react": "^7.31.11",
     "eslint-plugin-react-hooks": "^4.6.0",
@@ -251,12 +254,12 @@
     "tsx": "~4.15.6",
     "typedoc": "^0.24.6",
     "typescript": "~5.0.3",
+    "typescript-eslint": "~8.4.0",
     "utf-8-validate": "^5.0.10",
     "vitest": "~1.6.0",
     "wait-for-expect": "~3.0.2",
     "ws": "8.18.0",
-    "zod": "^3.21.4",
-    "@types/detect-port": "~1.3.5"
+    "zod": "^3.21.4"
   },
   "engines": {
     "npm": ">=7.0.0",

src/browser/sync/authentication_manager.ts

@@ -404,7 +404,7 @@ export class AuthenticationManager {
   private decodeToken(token: string) {
     try {
       return jwtDecode(token);
-    } catch (e) {
+    } catch {
       return null;
     }
   }

src/browser/sync/web_socket_manager.ts

@@ -321,7 +321,6 @@ export class WebSocketManager {
       }
       default: {
         // Enforce that the switch-case is exhaustive.
-        // eslint-disable-next-line  @typescript-eslint/no-unused-vars
         const _: never = this.socket;
       }
     }
@@ -367,7 +366,6 @@ export class WebSocketManager {
       }
       default: {
         // Enforce that the switch-case is exhaustive.
-        // eslint-disable-next-line  @typescript-eslint/no-unused-vars
         const _: never = this.socket;
         return Promise.resolve();
       }

src/bundler/context.ts

@@ -49,7 +49,6 @@ async function flushAndExit(exitCode: number, err?: any) {
     Sentry.captureException(err);
   }
   await Sentry.close();
-  // eslint-disable-next-line no-restricted-syntax
   return process.exit(exitCode);
 }
 

src/bundler/external.ts

@@ -225,7 +225,7 @@ export async function findExactVersionAndDependencies(
   try {
     const packageJsonString = ctx.fs.readUtf8File(modulePackageJsonPath);
     modulePackageJson = JSON.parse(packageJsonString);
-  } catch (error: any) {
+  } catch {
     return await ctx.crash({
       exitCode: 1,
       errorType: "invalid filesystem data",

src/bundler/fs.test.ts

@@ -1,4 +1,3 @@
-/* eslint-disable no-restricted-syntax */
 import { test, expect } from "vitest";
 import fs from "fs";
 import os from "os";

src/bundler/fs.ts

@@ -1,5 +1,6 @@
 // Disable our restriction on `throw` because these aren't developer-facing
 // error messages.
+/* eslint-disable no-restricted-imports */
 /* eslint-disable no-restricted-syntax */
 import chalk from "chalk";
 import stdFs, { Dirent, Mode, ReadStream, Stats } from "fs";

src/bundler/index.ts

@@ -127,7 +127,7 @@ async function doEsbuild(
       externalModuleNames: external.externalModuleNames,
       bundledModuleNames: external.bundledModuleNames,
     };
-  } catch (err) {
+  } catch {
     return await ctx.crash({
       exitCode: 1,
       errorType: "invalid filesystem data",