always use esm version of templates

Author: lobsterkatie

packages/nextjs/.eslintrc.js

@@ -11,4 +11,12 @@ module.exports = {
   rules: {
     '@sentry-internal/sdk/no-async-await': 'off',
   },
+  overrides: [
+    {
+      files: ['scripts/**/*.ts'],
+      parserOptions: {
+        project: ['../../tsconfig.dev.json'],
+      },
+    },
+  ],
 };

packages/nextjs/package.json

@@ -45,11 +45,11 @@
   "scripts": {
     "build": "run-p build:rollup build:types",
     "build:dev": "run-s build",
-    "build:rollup": "rollup -c rollup.npm.config.js",
+    "build:rollup": "ts-node scripts/buildRollup.ts",
     "build:types": "tsc -p tsconfig.types.json",
     "build:watch": "run-p build:rollup:watch build:types:watch",
     "build:dev:watch": "run-s build:watch",
-    "build:rollup:watch": "rollup -c rollup.npm.config.js --watch",
+    "build:rollup:watch": "nodemon --ext ts --watch src scripts/buildRollup.ts",
     "build:types:watch": "tsc -p tsconfig.types.json --watch",
     "build:npm": "ts-node ../../scripts/prepack.ts && npm pack ./build",
     "circularDepCheck": "madge --circular src/index.client.ts && madge --circular --exclude 'config/types\\.ts' src/index.server.ts # see https://github.com/pahen/madge/issues/306",

packages/nextjs/scripts/buildRollup.ts

@@ -0,0 +1,24 @@
+import * as childProcess from 'child_process';
+import * as fs from 'fs';
+import * as path from 'path';
+
+/**
+ * Run the given shell command, piping the shell process's `stdin`, `stdout`, and `stderr` to that of the current
+ * process. Returns contents of `stdout`.
+ */
+function run(cmd: string, options?: childProcess.ExecSyncOptions): string | Buffer {
+  return childProcess.execSync(cmd, { stdio: 'inherit', ...options });
+}
+
+run('yarn rollup -c rollup.npm.config.js');
+
+// Regardless of whether nextjs is using the CJS or ESM version of our SDK, we want the code from our templates to be in
+// ESM (since we'll be adding it onto page files which are themselves written in ESM), so copy the ESM versions of the
+// templates over into the CJS build directory. (Building only the ESM version and sticking it in both locations is
+// something which in theory Rollup could do, but it would mean refactoring our Rollup helper functions, which isn't
+// worth it just for this.)
+const cjsTemplateDir = 'build/cjs/config/templates/';
+const esmTemplateDir = 'build/esm/config/templates/';
+fs.readdirSync(esmTemplateDir).forEach(templateFile =>
+  fs.copyFileSync(path.join(esmTemplateDir, templateFile), path.join(cjsTemplateDir, templateFile)),
+);