fix: add node 20 compatibility for tests and build

jest.config.js: Add moduleNameMapper for Node.js built-ins in jsdom
- Maps undici, cheerio to mocks
- Maps node:stream/util/assert/buffer to polyfills
- Maps node:net/tls/http/https/async_hooks/url/querystring/diagnostics_channel to mocks

tsconfig.build.json: Add skipLibCheck and noImplicitAny
- Resolves type conflicts, supports legacy patterns

src/AutoSizer/index.tsx: Fix import - AutoSizerProps to Props as AutoSizerProps

src/CodeViewer/utils/lineNumberify.ts: Add newTree type annotation (AST.Element[])

src/ScrollContainer/index.tsx: Add callback types + multi-line JSX format
- Fixes tslint compliance

Add 9 mock files for undici, cheerio, and Node built-ins:
- undici.js, cheerio.js, cheerio_utils.js, node_async_hooks.js
- node_net.js, node_tls.js, node_url.js, node_querystring.js, diagnostics_channel.js

src/styles/tailwind/_base.scss: Auto-generated by build process

Result: All 6 test suites (17 tests) pass, yarn build and yarn test.prod working

Author: SB-ChetanKorde

__mocks__/cheerio.js

@@ -0,0 +1,4 @@
+// Mock for cheerio
+module.exports = {
+  load: () => (() => {}),
+};

__mocks__/cheerio_utils.js

@@ -0,0 +1,5 @@
+// Mock for cheerio/lib/utils
+module.exports = {
+  camelCase: (str) => str,
+  isEmptyObject: () => false,
+};

__mocks__/diagnostics_channel.js

@@ -0,0 +1,16 @@
+class TracingChannel {
+  constructor(name) {
+    this.name = name;
+  }
+  subscribe() {}
+  unsubscribe() {}
+  publish() {}
+  hasSubscribers() {
+    return false;
+  }
+}
+
+module.exports = {
+  channel: () => new TracingChannel(),
+  TracingChannel,
+};

__mocks__/node_async_hooks.js

@@ -0,0 +1,12 @@
+// Mock for node:async_hooks
+module.exports = {
+  createHook: () => ({
+    enable: () => {},
+    disable: () => {},
+  }),
+  executionAsyncResource: () => {},
+  executionAsyncId: () => 0,
+  triggerAsyncId: () => 0,
+  AsyncLocalStorage: class {},
+  AsyncResource: class {},
+};

__mocks__/node_net.js

@@ -0,0 +1 @@
+module.exports = {};

__mocks__/node_querystring.js

@@ -0,0 +1,3 @@
+// Mock for node:querystring
+const querystring = require('querystring');
+module.exports = querystring;

__mocks__/node_tls.js

@@ -0,0 +1 @@
+module.exports = {};

__mocks__/node_url.js

@@ -0,0 +1,3 @@
+// Mock for node:url
+const url = require('url');
+module.exports = url;

__mocks__/undici.js

@@ -0,0 +1,7 @@
+// Mock for undici to prevent loading Node.js built-in dependencies
+module.exports = {
+  fetch: () => Promise.resolve({ ok: true }),
+  Client: class {},
+  Pool: class {},
+  Agent: class {},
+};

jest.config.js

@@ -3,8 +3,25 @@ module.exports = {
   testEnvironment: 'jsdom',
   setupFilesAfterEnv: ['./setupTests.ts'],
   snapshotSerializers: ['enzyme-to-json/serializer'],
+  // Map modules to mocks/polyfills for Node 20 compatibility
   moduleNameMapper: {
     '\\.(css)$': '<rootDir>/__mocks__/styleMock.js',
+    '^cheerio$': '<rootDir>/__mocks__/cheerio.js',
+    '^cheerio/lib/utils$': '<rootDir>/__mocks__/cheerio_utils.js',
+    '^undici$': '<rootDir>/__mocks__/undici.js',
+    '^node:stream$': 'stream-browserify',
+    '^node:util$': 'util',
+    '^node:assert$': 'assert',
+    '^node:buffer$': 'buffer',
+    '^node:url$': '<rootDir>/__mocks__/node_url.js',
+    '^node:async_hooks$': '<rootDir>/__mocks__/node_async_hooks.js',
+    '^node:net$': '<rootDir>/__mocks__/node_net.js',
+    '^node:tls$': '<rootDir>/__mocks__/node_tls.js',
+    '^node:http$': '<rootDir>/__mocks__/node_net.js',
+    '^node:https$': '<rootDir>/__mocks__/node_tls.js',
+    '^node:events$': 'events',
+    '^node:querystring$': '<rootDir>/__mocks__/node_querystring.js',
+    '^node:diagnostics_channel$': '<rootDir>/__mocks__/diagnostics_channel.js',
   },
   testPathIgnorePatterns: ['/node_modules/'],
 };