feat: support esm projects (#375)

- new cli parameter `--ts-is-esm-project [bool]` /
`OPENAPI_TS_IS_ESM_PROJECT`
- detected automatically by default, from reading the closest
`package.json` to the output directory
- use the `--ts-is-esm-project` value to include / exclude `.ts`
extensions in imports
- change integration tests to use a mixture of commonjs and esm
- change e2e tests to use esm

Author: mnahkies

e2e/jest.config.js

@@ -1,12 +1,12 @@
-const base = require("../jest.base")
-const {name: displayName} = require("./package.json")
+import base from "../jest.base.js"
+import pkg from "./package.json" with {type: "json"}
 
 /**
  * @type { import('@jest/types').Config.ProjectConfig }
  */
 const config = {
   ...base,
-  displayName,
+  displayName: pkg.name,
 }
 
-module.exports = config
+export default config

e2e/package.json

@@ -5,6 +5,7 @@
   "author": "Michael Nahkies",
   "license": "MIT",
   "private": true,
+  "type": "module",
   "scripts": {
     "clean": "rm -rf ./dist && rm -rf ./src/generated",
     "generate": "./scripts/generate.sh",

e2e/src/express.entrypoint.ts

@@ -1,10 +1,10 @@
 import {type NextFunction, type Request, type Response, Router} from "express"
-import {bootstrap} from "./generated/server/express"
-import {createEscapeHatchesRouter} from "./routes/express/escape-hatches"
-import {createMediaTypesRouter} from "./routes/express/media-types"
-import {createRequestHeadersRouter} from "./routes/express/request-headers"
-import {createValidationRouter} from "./routes/express/validation"
-import {createErrorResponse} from "./shared"
+import {bootstrap} from "./generated/server/express/index.ts"
+import {createEscapeHatchesRouter} from "./routes/express/escape-hatches.ts"
+import {createMediaTypesRouter} from "./routes/express/media-types.ts"
+import {createRequestHeadersRouter} from "./routes/express/request-headers.ts"
+import {createValidationRouter} from "./routes/express/validation.ts"
+import {createErrorResponse} from "./shared.ts"
 
 function createRouter() {
   const router = Router()