replace tsc with swc for compiling TS source

.changeset/lemon-kings-type.md

@@ -0,0 +1,5 @@
+---
+'@itwin/itwinui-react': minor
+---
+
+Replaced dependency on `tslib` with `@swc/helpers`. This is used mainly by the CommonJS build.

.changeset/strange-spiders-count.md

@@ -0,0 +1,5 @@
+---
+'@itwin/itwinui-react': patch
+---
+
+The build output is now (again) formatted using `prettier` for easier debugging.

.changeset/witty-ties-protect.md

@@ -0,0 +1,5 @@
+---
+'@itwin/itwinui-react': patch
+---
+
+Removed all code comments from the build output.

packages/itwinui-react/package.json

@@ -62,9 +62,10 @@
     "ux"
   ],
   "scripts": {
-    "build": "pnpm clean:build && tsc -p tsconfig.cjs.json && tsc -p tsconfig.esm.json && tsc -p tsconfig.react-table.json && pnpm build:styles && pnpm build:post",
+    "build": "pnpm clean:build && pnpm build:js && pnpm build:styles && pnpm build:types && pnpm build:post",
+    "build:js": "node ./scripts/build.mjs",
+    "build:types": "tsc -p tsconfig.cjs.json && tsc -p tsconfig.esm.json && tsc -p tsconfig.react-table.json",
     "build:styles": "vite build src/styles.js",
-    "build:watch": "concurrently \"tsc -p tsconfig.cjs.json --watch\" \"tsc -p tsconfig.esm.json --watch\"",
     "build:post": "node ./scripts/postBuild.mjs",
     "clean:build": "rimraf esm && rimraf cjs && rimraf react-table.d.ts",
     "clean:coverage": "rimraf coverage",
@@ -85,11 +86,11 @@
   "dependencies": {
     "@floating-ui/react": "^0.26.10",
     "@itwin/itwinui-illustrations-react": "^2.1.0",
+    "@swc/helpers": "^0.5.11",
     "classnames": "^2.3.2",
     "jotai": "^2.8.0",
     "react-table": "^7.8.0",
-    "react-transition-group": "^4.4.5",
-    "tslib": "^2.6.0"
+    "react-transition-group": "^4.4.5"
   },
   "devDependencies": {
     "@swc/cli": "^0.3.12",

packages/itwinui-react/scripts/build.mjs

@@ -0,0 +1,41 @@
+/*---------------------------------------------------------------------------------------------
+ * Copyright (c) Bentley Systems, Incorporated. All rights reserved.
+ * See LICENSE.md in the project root for license terms and full copyright notice.
+ *--------------------------------------------------------------------------------------------*/
+import { execSync } from 'node:child_process';
+
+// https://swc.rs/docs/usage/cli
+const swcOptions = {
+  shared: [
+    '--strip-leading-paths',
+    '--no-swcrc',
+    '--ignore **/*.test.*,**/styles.js/*,**/styles*',
+  ].join(' '),
+
+  // https://swc.rs/docs/configuration/compilation
+  compilerOptions: [
+    '',
+    'jsc.parser.syntax=typescript',
+    'jsc.parser.tsx=true',
+    'jsc.transform.react.useBuiltins=true',
+    'jsc.target=es2020',
+    'jsc.minify.format.comments=false',
+    'jsc.externalHelpers=true',
+  ].join(' -C '),
+
+  get esm() {
+    return [this.shared, this.compilerOptions, '-C module.type=es6'].join(' ');
+  },
+
+  get cjs() {
+    return [this.shared, this.compilerOptions, '-C module.type=commonjs'].join(
+      ' ',
+    );
+  },
+};
+
+execSync(`pnpm swc src -d esm ${swcOptions.esm}`);
+console.log('✓ Built esm.');
+
+execSync(`pnpm swc src -d cjs ${swcOptions.cjs}`);
+console.log('✓ Built cjs.');

packages/itwinui-react/scripts/postBuild.mjs

@@ -3,7 +3,7 @@
  * See LICENSE.md in the project root for license terms and full copyright notice.
  *--------------------------------------------------------------------------------------------*/
 import fs from 'node:fs';
-import { exec } from 'node:child_process';
+import { execSync } from 'node:child_process';
 
 // This creates a dummy package.json file in the cjs folder.
 // Without this, all cjs files would need the .cjs extension
@@ -15,10 +15,12 @@ try {
 }
 
 // Run prettier on all compiled output because it gets jumbled by tsc.
-exec('pnpm exec prettier --write "{esm,cjs}/**/*.js"', (error) => {
-  if (error) {
-    console.error('Error when running prettier', error);
-  } else {
-    console.log('✓ Finished compiling @itwin/itwinui-react');
-  }
-});
+try {
+  execSync(
+    'npx prettier --write --ignore-path="../../.gitignore" "{esm,cjs}/**/*.js"',
+  );
+} catch (error) {
+  console.error('Error when running prettier', error);
+}
+
+console.log('\x1b[32m✓ Finished building @itwin/itwinui-react');

packages/itwinui-react/tsconfig.build.json

@@ -3,6 +3,6 @@
   "files": ["src/index.ts"],
   "compilerOptions": {
     "noUnusedLocals": false,
-    "importHelpers": true
+    "emitDeclarationOnly": true
   }
 }