Add ESLint and lint codebase

.prettierignore → .eslintignore

@@ -1 +1,2 @@
 __tests__/*/results*.json5
+dist

.eslintrc.js

@@ -0,0 +1,116 @@
+module.exports = {
+  extends: [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/eslint-recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:import/errors",
+    "plugin:import/typescript",
+    "prettier",
+  ],
+  plugins: ["tsdoc", "simple-import-sort", "import"],
+  env: {
+    node: true,
+    es6: true,
+  },
+  rules: {
+    // We need this for our `GraphileEngine` namespace
+    "@typescript-eslint/no-namespace": "off",
+    "@typescript-eslint/consistent-type-imports": "error",
+    "no-confusing-arrow": "off",
+    "no-else-return": "off",
+    "no-underscore-dangle": "off",
+    "no-restricted-syntax": "off",
+    "no-await-in-loop": "off",
+    "tsdoc/syntax": "error",
+    "@typescript-eslint/no-unused-vars": [
+      "error",
+      {
+        argsIgnorePattern: "^_",
+        varsIgnorePattern: "^_",
+        args: "after-used",
+        ignoreRestSiblings: true,
+      },
+    ],
+
+    /*
+     * simple-import-sort seems to be the most stable import sorting currently,
+     * disable others
+     */
+    "simple-import-sort/imports": "error",
+    "simple-import-sort/exports": "error",
+    "sort-imports": "off",
+    "import/order": "off",
+
+    "import/extensions": ["error", "ignorePackages"],
+    "import/no-deprecated": "warn",
+
+    // Apply has been more optimised than spread, use whatever feels right.
+    "prefer-spread": "off",
+
+    // note you must disable the base rule as it can report incorrect errors
+    "no-duplicate-imports": "off",
+    "import/no-duplicates": "error",
+  },
+  overrides: [
+    // Rules for interfaces.ts files
+    {
+      files: ["**/interfaces.ts"],
+      rules: {
+        "no-restricted-syntax": [
+          "error",
+          {
+            selector: "TSModuleDeclaration[kind='global']",
+            message:
+              "No `declare global` allowed in `interface.ts` files since these type-only files may not be imported by dependents, recommend adding to `index.ts` instead.",
+          },
+        ],
+      },
+    },
+
+    // Rules for TypeScript only
+    {
+      files: ["*.ts", "*.tsx"],
+      parser: "@typescript-eslint/parser",
+      rules: {
+        "no-dupe-class-members": "off",
+        "no-undef": "off",
+        // This rule doesn't understand import of './js'
+        "import/no-unresolved": "off",
+      },
+    },
+
+    // Rules for JavaScript only
+    {
+      files: ["*.js", "*.jsx", "*.mjs", "*.cjs"],
+      rules: {
+        "tsdoc/syntax": "off",
+        "import/extensions": "off",
+      },
+    },
+
+    // Stricter rules for source code
+    {
+      files: ["*/*/src/**/*.ts", "*/*/src/**/*.tsx"],
+      parser: "@typescript-eslint/parser",
+      parserOptions: {
+        project: true,
+      },
+      rules: {},
+    },
+
+    // Rules for tests only
+    {
+      files: ["**/__tests__/**/*.{ts,js,mts,mjs}"],
+      rules: {
+        // Disable these to enable faster test writing
+        "prefer-const": "off",
+        "@typescript-eslint/no-explicit-any": "off",
+        "@typescript-eslint/no-unused-vars": "off",
+        "@typescript-eslint/explicit-function-return-type": "off",
+
+        // We don't normally care about race conditions in tests
+        "require-atomic-updates": "off",
+      },
+    },
+  ],
+};

.github/workflows/tests.yml

@@ -1,14 +1,28 @@
-name: Tests
+name: CI
 
 on:
   push:
-    branches: [ "main" ]
+    branches: ["main"]
   pull_request:
-    branches: [ "main" ]
+    branches: ["main"]
 
 jobs:
-  build:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: 20.x
+          cache: "npm"
+      - run: yarn
+      # We need to build for linting due to `import` checks in `__tests__` files
+      - run: yarn build
+      - run: yarn lint
 
+  tests:
     runs-on: ubuntu-latest
 
     strategy:
@@ -17,14 +31,14 @@ jobs:
         graphql-version: [15.x, 16.x, ^17.0.0-alpha.3]
 
     steps:
-    - uses: actions/checkout@v4
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v3
-      with:
-        node-version: ${{ matrix.node-version }}
-        cache: 'npm'
-    - run: yarn
-    - run: yarn build
-    # We must build BEFORE we replace the GraphQL version (because otherwise the types don't match)
-    - run: yarn add graphql@${{ matrix.graphql-version }}
-    - run: yarn test
+      - uses: actions/checkout@v4
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: "npm"
+      - run: yarn
+      - run: yarn build
+      # We must build BEFORE we replace the GraphQL version (because otherwise the types don't match)
+      - run: yarn add graphql@${{ matrix.graphql-version }}
+      - run: yarn test

__tests__/common.mjs

@@ -1,9 +1,10 @@
 // @ts-check
 
-import { diff } from "jest-diff";
 import assert from "assert";
 import { readdir, readFile, writeFile } from "fs/promises";
+import { diff } from "jest-diff";
 import JSON5 from "json5";
+
 import { printResults } from "../dist/index.js";
 
 /** @import { SourceLike, CheckOperationsResult } from '../dist/index.js' */

__tests__/depth-limit-basics/tests.test.mjs

@@ -1,11 +1,12 @@
 // @ts-check
 
+import { it } from "node:test";
+
 import {
   checkOperations,
   filterBaseline,
   generateBaseline,
 } from "../../dist/index.js";
-import { it } from "node:test";
 import { getDirHelpers } from "../common.mjs";
 
 const __dirname = new URL(".", import.meta.url).pathname;

__tests__/depth-limit-large-schema/tests.test.mjs

@@ -1,7 +1,8 @@
 // @ts-check
 
-import { checkOperations } from "../../dist/index.js";
 import { it } from "node:test";
+
+import { checkOperations } from "../../dist/index.js";
 import { getDirHelpers } from "../common.mjs";
 
 const __dirname = new URL(".", import.meta.url).pathname;

package.json

@@ -9,9 +9,17 @@
   "scripts": {
     "build": "tsc -p tsconfig.build.json",
     "watch": "tsc -p tsconfig.build.json -w",
+    "lint": "yarn run eslint . && yarn prettier:check",
+    "lint:fix": "yarn run eslint --fix . && yarn prettier:fix",
+    "test": "node --test",
     "prepack": "rm -Rf dist && yarn build",
     "version": "node scripts/postversion.mjs && git add src/version.ts",
-    "test": "node --test"
+    "-----": "-----",
+    "eslint": "eslint --ext .js,.jsx,.ts,.tsx,.mjs,.cjs",
+    "prettier": "prettier --cache --ignore-path ./.eslintignore",
+    "prettier:all": "yarn prettier '**/*.{json,md,mdx,html,js,jsx,ts,tsx,mjs,cjs,mts,cts,yml}'",
+    "prettier:fix": "yarn prettier:all --write",
+    "prettier:check": "yarn prettier:all --list-different"
   },
   "repository": {
     "type": "git",
@@ -44,10 +52,11 @@
     "@types/node": "^20.14.2",
     "@typescript-eslint/eslint-plugin": "^7.13.0",
     "@typescript-eslint/parser": "^7.13.0",
-    "eslint": "^9.5.0",
+    "eslint": "8.x",
     "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-import": "^2.29.1",
     "eslint-plugin-simple-import-sort": "^12.1.0",
+    "eslint-plugin-tsdoc": "^0.3.0",
     "eslint_d": "^13.1.2",
     "jest-diff": "^29.7.0",
     "prettier": "^3.3.2",

scripts/postversion.mjs

@@ -1,4 +1,4 @@
-import { writeFile, readFile } from "node:fs/promises";
+import { readFile, writeFile } from "node:fs/promises";
 import { fileURLToPath } from "node:url";
 
 const __dirname = fileURLToPath(new URL(".", import.meta.url)).replace(

src/DepthVisitor.ts

@@ -1,17 +1,21 @@
 import * as assert from "node:assert";
-import {
+
+import type {
   ASTVisitor,
   FragmentDefinitionNode,
+  GraphQLOutputType,
+  OperationDefinitionNode,
+} from "graphql";
+import {
   GraphQLList,
   GraphQLNonNull,
-  GraphQLOutputType,
   isCompositeType,
   isNamedType,
   Kind,
-  OperationDefinitionNode,
 } from "graphql";
-import { RulesContext } from "./rulesContext";
-import { RuleError } from "./ruleError";
+
+import { RuleError } from "./ruleError.js";
+import type { RulesContext } from "./rulesContext.js";
 
 interface DepthInfo {
   current: number;
@@ -287,13 +291,13 @@ export function DepthVisitor(context: RulesContext): ASTVisitor {
 
   return {
     Document: {
-      enter(node) {
+      enter(_node) {
         if (!state.complete) {
           console.warn("Previous DepthVisitor didn't complete cleanly");
         }
         state = newState();
       },
-      leave(node) {
+      leave(_node) {
         // Finalize depths by applying all the fragment depths to the operations
         const resolvedOperations = resolveRoots(state);
         const resolvedPreset = context.getResolvedPreset();
@@ -437,7 +441,7 @@ export function DepthVisitor(context: RulesContext): ASTVisitor {
         currentRoot = newRoot(node);
         state.roots.push(currentRoot);
       },
-      leave(node) {
+      leave(_node) {
         currentRoot = null;
       },
     },
@@ -451,7 +455,7 @@ export function DepthVisitor(context: RulesContext): ASTVisitor {
         currentRoot = newRoot(node);
         state.roots.push(currentRoot);
       },
-      leave(node) {
+      leave(_node) {
         currentRoot = null;
       },
     },
@@ -490,7 +494,7 @@ export function DepthVisitor(context: RulesContext): ASTVisitor {
           // Visiting same fragment again; ignore
         }
       },
-      leave(node) {
+      leave(_node) {
         // No specific action required
       },
     },

src/baseline.ts

@@ -1,4 +1,4 @@
-import {
+import type {
   Baseline,
   CheckDocumentOutput,
   SourceResultsBySourceName,
@@ -11,7 +11,7 @@ export function generateBaseline(
     version: 1,
     operations: {},
   };
-  for (const [sourceName, { output }] of Object.entries(resultsBySourceName)) {
+  for (const [_sourceName, { output }] of Object.entries(resultsBySourceName)) {
     const { errors } = output;
     for (const error of errors) {
       if ("infraction" in error) {

src/cli.ts

@@ -1,13 +1,16 @@
 #!/usr/bin/env node
+import { open, readdir, readFile, stat, writeFile } from "node:fs/promises";
+import type { ParseArgsConfig } from "node:util";
+import { parseArgs } from "node:util";
+
 import JSON5 from "json5";
-import { parseArgs, ParseArgsConfig } from "node:util";
-import { checkOperations } from "./main";
-import { open, readdir, stat, readFile, writeFile } from "node:fs/promises";
 import { kjsonlLines } from "kjsonl";
-import { SourceLike } from "./interfaces";
+
+import { filterBaseline, generateBaseline } from "./baseline.js";
+import type { SourceLike } from "./interfaces.js";
+import { checkOperations } from "./main.js";
 import { printResults } from "./print.js";
-import { filterBaseline, generateBaseline } from "./baseline";
-import { version } from "./version";
+import { version } from "./version.js";
 
 const parseArgsConfig = {
   options: {

src/index.ts

@@ -1,12 +1,12 @@
+export { filterBaseline, generateBaseline } from "./baseline.js";
 export {
+  Baseline,
+  CheckOperationsResult,
   SourceLike,
   SourceResultsBySourceName as SourceResultBySourceName,
-  CheckOperationsResult,
-  Baseline,
 } from "./interfaces.js";
 export { checkOperations } from "./main.js";
 export { printResults } from "./print.js";
-export { filterBaseline, generateBaseline } from "./baseline.js";
 
 declare global {
   namespace GraphileConfig {

src/interfaces.ts

@@ -1,4 +1,4 @@
-import { GraphQLFormattedError } from "graphql";
+import type { GraphQLFormattedError } from "graphql";
 
 export interface WorkerData {
   configPath: string | null | undefined;