CL-1543 | Patch the dynamic import code after tsc compile

Author: dhruvparekh12

package-lock.json

@@ -29,6 +29,7 @@
     "@rollup/plugin-commonjs": "^28.0.2",
     "@rollup/plugin-json": "^6.1.0",
     "@rollup/plugin-node-resolve": "^16.0.0",
+    "@rollup/plugin-typescript": "^12.1.2",
     "@types/express": "^4.17.21",
     "@types/express-serve-static-core": "^4.17.34",
     "adm-zip": "^0.5.16",
@@ -92,7 +93,8 @@
     "version": "oclif readme && git add README.md",
     "build": "npm run clean && npm run compile",
     "clean": "rm -rf ./dist tsconfig.build.tsbuildinfo",
-    "compile": "tsc -b tsconfig.json",
+    "compile": "tsc -b tsconfig.json && npm run patch-load-data-url",
+    "patch-load-data-url": "node scripts/patch-load-data-url-file.js",
     "prepack": "npm run build && oclif manifest && oclif readme",
     "test:unit": "mocha --forbid-only \"test/unit/**/*.test.ts\"",
     "test:unit:report": "nyc --extension .ts mocha --forbid-only \"test/unit/**/*.test.ts\""

package.json

@@ -0,0 +1,30 @@
+// The tsc compiler currently compiles to "commonjs" output as per the tsconfig.
+// As a result, the use of dynamic import "import()" in the cloud-function logic, gets replaced with "require()" in the dist/ output. 
+// "require()" however does not support importing modules from data url strings causing this logic to break.
+// Therefore, we patch the dist/ output to again use dynamic imports "import()" after tsc compilation.
+
+const rollup = require('rollup');
+const typescript = require('@rollup/plugin-typescript');
+const path = require('path');
+
+async function transpileTsFileToESM(inputFile, outputFile) {
+  const bundle = await rollup.rollup({
+    input: inputFile,
+    plugins: [typescript({ module: 'esnext', declaration: false })],
+  });
+
+  await bundle.write({
+    file: outputFile,
+    format: 'esm',
+    sourcemap: false,
+  });
+}
+
+async function patchLoadDataURLFunction() {
+  const loadDataURLInputFilePath = path.join(process.cwd(), 'src/util/cloud-function/load-data-url.ts');
+  const loadDataURLOutputFilePath = path.join(process.cwd(), 'dist/util/cloud-function/load-data-url.js');
+  await transpileTsFileToESM(loadDataURLInputFilePath, loadDataURLOutputFilePath);
+  console.log(`${loadDataURLInputFilePath} : File patched successfully`);
+}
+
+patchLoadDataURLFunction();

scripts/patch-load-data-url-file.js

@@ -4,7 +4,7 @@ import express, {
   Response,
 } from 'express';
 import { Express } from 'express-serve-static-core';
-import path, { normalize } from "path";
+import path from "path";
 
 import { CloudFunctionsValidator } from "./cloud-functions-validator";
 import {
@@ -20,6 +20,7 @@ import rollup from "rollup";
 import { nodeResolve } from "@rollup/plugin-node-resolve";
 import commonjs from "@rollup/plugin-commonjs";
 import json from "@rollup/plugin-json";
+import { loadDataURL } from './load-data-url';
 
 export class CloudFunctions {
   private cloudFunctionsDirectoryPath: string;
@@ -189,7 +190,7 @@ export class CloudFunctions {
   private async buildHandlerForFilepath(cloudFunctionFilePath: string) {
     const bundle = await rollup.rollup({
       input: cloudFunctionFilePath,
-      plugins: [nodeResolve({ preferBuiltins: false }), commonjs(), json()],
+      plugins: [nodeResolve({ preferBuiltins: true }), commonjs(), json()],
     });
 
     const { output } = await bundle.generate({
@@ -202,7 +203,7 @@ export class CloudFunctions {
     const builtCodeInDataURLFormat =
       "data:text/javascript;base64," + Buffer.from(builtCode).toString("base64");
 
-    const module = await import(builtCodeInDataURLFormat);
+    const module = await loadDataURL(builtCodeInDataURLFormat);
 
     let handler = null;
     const isDefaultExportESModuleFunction = typeof module.default === 'function';

src/util/cloud-function/cloud-functions.ts

@@ -0,0 +1,3 @@
+export function loadDataURL(dataURL: string) {
+    return import(dataURL);
+}