refactor: introduce eslint

.eslintignore

@@ -0,0 +1,5 @@
+.yalc
+.vscode
+.github
+node_modules
+build

.eslintrc

@@ -0,0 +1,65 @@
+{
+  "root": true,
+  "parser": "@typescript-eslint/parser",
+  "parserOptions": {
+    "project": ["tsconfig.json"]
+  },
+  "plugins": [
+    // This enables using new lint rules powered by the TypeScript compiler API.
+    // https://github.com/typescript-eslint/typescript-eslint
+    "@typescript-eslint",
+    // This makes it so the IDE reports lint rejections as warnings only. This is
+    // better than errors because most lint rejections are not runtime errors. This
+    // allows IDE errors to be exclusive for e.g. static type errors which often are
+    // reflective of real runtime errors.
+    // https://github.com/bfanger/eslint-plugin-only-warn
+    "only-warn",
+    // This enables the use of a lint rule to reject function declarations. This is
+    // preferable as a way to encourage higher order function usage. For example it is not
+    // possible to wrap a function declaration with Open Telemetry instrumentation but it is
+    // possible to wrap an arrow function since its an expression.
+    // https://github.com/TristonJ/eslint-plugin-prefer-arrow
+    "prefer-arrow",
+    // This enables the use of a lint rule to reject use of @deprecated functions.
+    // https://github.com/gund/eslint-plugin-deprecation
+    "deprecation",
+    // Import sorting integrated into ESLint.
+    // https://github.com/lydell/eslint-plugin-simple-import-sort
+    "simple-import-sort",
+    // https://github.com/microsoft/tsdoc/tree/master/eslint-plugin
+    "tsdoc"
+  ],
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/eslint-recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:@typescript-eslint/recommended-requiring-type-checking",
+    "prettier"
+  ],
+  "overrides": [],
+  "rules": {
+    "@typescript-eslint/consistent-type-imports": "warn",
+    // Enforce backticks
+    // Note you must disable the base rule as it can report incorrect errors.
+    "quotes": "off",
+    "@typescript-eslint/quotes": ["warn", "backtick"],
+    "tsdoc/syntax": "warn",
+    "simple-import-sort/imports": [
+      "warn",
+      {
+        "groups": []
+      }
+    ],
+    "simple-import-sort/exports": "warn",
+    "deprecation/deprecation": "warn",
+    "prefer-arrow/prefer-arrow-functions": "warn",
+    // TypeScript makes these safe & effective
+    "no-case-declarations": "off",
+    // Same approach used by TypeScript noUnusedLocals
+    "@typescript-eslint/no-unused-vars": ["warn", { "varsIgnorePattern": "^_", "argsIgnorePattern": "^_" }],
+    // Needed when working with .mts/.cts where a lone e.g. <T> is not allowed
+    "@typescript-eslint/no-unnecessary-type-constraint": "off",
+    // Useful for organizing Types
+    "@typescript-eslint/no-namespace": "off"
+  }
+}

examples/authentication-via-http-header.ts

@@ -1,10 +1,10 @@
 import { GraphQLClient } from '../src/index.js'
-;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+;(async () => {
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const graphQLClient = new GraphQLClient(endpoint, {
     headers: {
-      authorization: 'Bearer MY_TOKEN',
+      authorization: `Bearer MY_TOKEN`,
     },
   })
 

examples/batching-requests.ts

@@ -1,6 +1,6 @@
 import { batchRequests } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://api.spacex.land/graphql/'
+  const endpoint = `https://api.spacex.land/graphql/`
 
   const query1 = /* GraphQL */ `
     query ($id: ID!) {
@@ -11,7 +11,7 @@ import { batchRequests } from '../src/index.js'
     }
   `
   const variables1 = {
-    id: 'C105',
+    id: `C105`,
   }
 
   interface TData1 {
@@ -41,7 +41,7 @@ import { batchRequests } from '../src/index.js'
   `
 
   const variables3 = {
-    id: 'B1015',
+    id: `B1015`,
   }
 
   interface TData3 {

examples/cookie-support-for-node.ts

@@ -1,12 +1,12 @@
-;(global as any).fetch = require('fetch-cookie/node-fetch')(require('node-fetch'))
+;(global as any).fetch = require(`fetch-cookie/node-fetch`)(require(`node-fetch`))
 
 import { GraphQLClient } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const graphQLClient = new GraphQLClient(endpoint, {
     headers: {
-      authorization: 'Bearer MY_TOKEN',
+      authorization: `Bearer MY_TOKEN`,
     },
   })
 

examples/custom-fetch.ts

@@ -1,7 +1,7 @@
-import fetch from 'cross-fetch'
 import { GraphQLClient } from '../src/index.js'
+import fetch from 'cross-fetch'
 ;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const graphQLClient = new GraphQLClient(endpoint, { fetch: fetch })
 

examples/error-handling.ts

@@ -1,6 +1,6 @@
 import { request } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const query = /* GraphQL */ `
     {

examples/passing-custom-header-per-request.ts

@@ -1,10 +1,10 @@
 import { GraphQLClient } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const client = new GraphQLClient(endpoint, {
     headers: {
-      authorization: 'Bearer MY_TOKEN',
+      authorization: `Bearer MY_TOKEN`,
     },
   })
 
@@ -20,8 +20,8 @@ import { GraphQLClient } from '../src/index.js'
   `
 
   const requestHeaders = {
-    authorization: 'Bearer MY_TOKEN_2',
-    'x-custom': 'foo',
+    authorization: `Bearer MY_TOKEN_2`,
+    'x-custom': `foo`,
   }
 
   interface TData {

examples/passing-more-options-to-fetch.ts

@@ -1,10 +1,10 @@
 import { GraphQLClient } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const graphQLClient = new GraphQLClient(endpoint, {
-    credentials: 'include',
-    mode: 'cors',
+    credentials: `include`,
+    mode: `cors`,
   })
 
   const query = /* GraphQL */ `

examples/receiving-a-raw-response.ts

@@ -1,6 +1,6 @@
 import { rawRequest } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const query = /* GraphQL */ `
     {

examples/typed-document-node.ts

@@ -1,9 +1,8 @@
-import { TypedDocumentNode } from '@graphql-typed-document-node/core'
+import { GraphQLClient,request } from '../src/index.js'
+import type { TypedDocumentNode } from '@graphql-typed-document-node/core'
 import { parse } from 'graphql'
-
-import { request, GraphQLClient } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://graphql-yoga.com/api/graphql'
+  const endpoint = `https://graphql-yoga.com/api/graphql`
 
   const query: TypedDocumentNode<{ greetings: string }, never | Record<any, never>> = parse(/* GraphQL */ `
     query greetings {
@@ -18,7 +17,7 @@ import { request, GraphQLClient } from '../src/index.js'
   console.log(data.greetings)
 })().catch(console.error)
 ;(async function () {
-  const endpoint = 'https://graphql-yoga.com/api/graphql'
+  const endpoint = `https://graphql-yoga.com/api/graphql`
 
   const client = new GraphQLClient(endpoint)
 

examples/using-variables.ts

@@ -1,6 +1,6 @@
 import { request } from '../src/index.js'
 ;(async function () {
-  const endpoint = 'https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr'
+  const endpoint = `https://api.graph.cool/simple/v1/cixos23120m0n0173veiiwrjr`
 
   const query = /* GraphQL */ `
     query getMovie($title: String!) {
@@ -14,7 +14,7 @@ import { request } from '../src/index.js'
   `
 
   const variables = {
-    title: 'Inception',
+    title: `Inception`,
   }
 
   interface TData {

package.json

@@ -44,8 +44,10 @@
     "build:docs": "doctoc README.md --notitle",
     "dev": "rm -rf dist && tsc --watch",
     "format": "prettier --write .",
+    "lint": "eslint . --ext .ts,.tsx --fix",
     "check:types": "pnpm tsc --noEmit",
     "check:format": "prettier --check .",
+    "check:lint": "eslint . --ext .ts,.tsx --max-warnings 0",
     "prepublishOnly": "pnpm build",
     "build": "pnpm clean && pnpm build:cjs && pnpm build:esm",
     "build:cjs": "pnpm tsc --project tsconfig.cjs.json && echo '{\"type\":\"commonjs\"}' > build/cjs/package.json",
@@ -74,11 +76,20 @@
     "@types/extract-files": "^8.1.1",
     "@types/node": "^18.11.18",
     "@types/ws": "^8.5.4",
+    "@typescript-eslint/eslint-plugin": "^5.52.0",
+    "@typescript-eslint/parser": "^5.52.0",
     "@vitest/coverage-c8": "^0.28.2",
     "apollo-server-express": "^3.11.1",
     "body-parser": "^1.20.1",
     "doctoc": "^2.2.1",
     "dripip": "^0.10.0",
+    "eslint": "^8.34.0",
+    "eslint-config-prettier": "^8.6.0",
+    "eslint-plugin-deprecation": "^1.3.3",
+    "eslint-plugin-only-warn": "^1.1.0",
+    "eslint-plugin-prefer-arrow": "^1.2.3",
+    "eslint-plugin-simple-import-sort": "^10.0.0",
+    "eslint-plugin-tsdoc": "^0.2.17",
     "express": "^4.18.2",
     "fetch-cookie": "^2.1.0",
     "get-port": "^6.1.2",