chore(monocdk): support barrel imports (#6996)

chore(monocdk): support barrel imports (#6996)

This change enables an alternative syntax for importing submodules from monocdk:

    import * as s3 from 'monocdk-experiment/aws-s3';

In addition to the currently supported syntax:

    import { aws_s3 as s3 } from 'monocdk-experiment';

The new syntax will make it easy to migrate from existing CDK codebase and also makes it easier to namespace submodule imports by consumers.

To that end, we hoisted the submodules from `src` to be direct subdirectories of the package (otherwise, the barrel import would have been `monocdk-experiment/src/aws-s3`).

Credits: @CaerusKaru

Author: Elad Ben-Israel

packages/@monocdk-experiment/assert/clone.sh

@@ -15,4 +15,7 @@ done
 
 npx rewrite-imports {lib,test}/*.ts jest.ts
 
-
+# symlink the full staged monocdk from the staging directory to node_modules
+rm -fr node_modules/monocdk-experiment
+mkdir -p node_modules
+ln -s $PWD/../../monocdk-experiment/staging node_modules/monocdk-experiment

packages/@monocdk-experiment/assert/package.json

@@ -5,7 +5,7 @@
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
   "scripts": {
-    "build": "./clone.sh && cdk-build",
+    "build": "cdk-build",
     "watch": "cdk-watch",
     "lint": "cdk-lint",
     "test": "cdk-test",
@@ -15,6 +15,7 @@
     "build+test": "npm run build && npm test"
   },
   "cdk-build": {
+    "pre": [ "./clone.sh" ],
     "eslint": {
       "disable": true
     },

packages/monocdk-experiment/.gitignore

@@ -2,4 +2,4 @@
 *.d.ts
 !deps.js
 !gen.js
-src/
+staging/

packages/monocdk-experiment/build.sh

@@ -33,6 +33,6 @@ cd ${scriptdir}
 mkdir -p dist/js
 cp ${tarball} dist/js
 
-# copying src/ so this module will also work as a local dependency (e.g. for modules under @monocdk-experiment/*).
-rm -fr src
-rsync -av ${unpacked}/src/ src/
+# so this module will also work as a local dependency (e.g. for modules under @monocdk-experiment/*).
+rm -fr staging
+mv ${unpacked} staging

packages/monocdk-experiment/deps.js

@@ -31,8 +31,6 @@ for (const dir of modules) {
     continue;
   }
 
-
-
   if (!exists) {
     console.error(`missing dependency: ${meta.name}`);
     errors = true;

packages/monocdk-experiment/gen.js

@@ -34,8 +34,6 @@ const exclude_files = [
 async function main() {
   const outdir = path.join(await fs.mkdtemp(path.join(os.tmpdir(), 'monocdk-')), 'package');
 
-  const srcdir = path.join(outdir, 'src');
-
   console.error(`generating monocdk at ${outdir}`);
   const reexports = [];
 
@@ -89,7 +87,7 @@ async function main() {
 
     const basename = path.basename(moduledir);
     const files = await fs.readdir(moduledir);
-    const targetdir = path.join(srcdir, basename);
+    const targetdir = path.join(outdir, basename);
     for (const file of files) {
       const source = path.join(moduledir, file);
 
@@ -150,12 +148,12 @@ async function main() {
     }    
   }
 
-  await fs.writeFile(path.join(srcdir, 'index.ts'), reexports.join('\n'));
+  await fs.writeFile(path.join(outdir, 'index.ts'), reexports.join('\n'));
 
   console.error(`rewriting "import" statements...`);
-  const sourceFiles = await findSources(srcdir);
+  const sourceFiles = await findSources(outdir);
   for (const source of sourceFiles) {
-    await rewriteImports(srcdir, source);
+    await rewriteImports(outdir, source);
   }
 
   // copy tsconfig.json and .npmignore

packages/monocdk-experiment/package.json

@@ -2,8 +2,8 @@
   "name": "monocdk-experiment",
   "version": "0.0.0",
   "description": "An experiment to bundle the entire CDK into a single module",
-  "main": "src/index.js",
-  "types": "src/index.d.ts",
+  "main": "index.js",
+  "types": "index.d.ts",
   "repository": {
     "type": "git",
     "url": "https://github.com/aws/aws-cdk.git"