From 4bb6fbb05a939cb353ce368469e1d31dc7579062 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=82=92=E7=B1=B3=E7=B2=89?= <970451823@qq.com>
Date: Mon, 3 Jun 2024 15:49:39 +0800
Subject: [PATCH] Feat/auto loader (#140)

* feat: prerelease autoloader

* feat: prerelease autoloader

* feat: make autoloader covers shadow dom

* feat: make autoloader covers shadow dom

* feat: autoloader for banana
---
 .changeset/tender-pianos-prove.md        |  6 ++
 packages/banana/src/banana-autoloader.ts | 88 ++++++++++++++++++++++++
 rollup.config.mjs                        | 22 +++++-
 tsconfig.json                            |  1 +
 4 files changed, 116 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/tender-pianos-prove.md
 create mode 100644 packages/banana/src/banana-autoloader.ts

diff --git a/.changeset/tender-pianos-prove.md b/.changeset/tender-pianos-prove.md
new file mode 100644
index 00000000..63afa8b3
--- /dev/null
+++ b/.changeset/tender-pianos-prove.md
@@ -0,0 +1,6 @@
+---
+'@banana-ui/banana': minor
+'@banana-ui/react': minor
+---
+
+Autoloader for banana.
diff --git a/packages/banana/src/banana-autoloader.ts b/packages/banana/src/banana-autoloader.ts
new file mode 100644
index 00000000..b42bf994
--- /dev/null
+++ b/packages/banana/src/banana-autoloader.ts
@@ -0,0 +1,88 @@
+// Inpired by https://github.com/shoelace-style/shoelace/blob/next/src/shoelace-autoloader.ts
+
+function getBasePath(subpath = '') {
+  const scripts = [...document.getElementsByTagName('script')] as HTMLScriptElement[];
+  const autoloader = scripts.find((script) => script.src.includes('banana-autoloader')) as HTMLScriptElement;
+  const basePath = autoloader.src.split('/').slice(0, -1).join('/');
+
+  // Return the base path without a trailing slash. If one exists, append the subpath separated by a slash.
+  return basePath.replace(/\/$/, '') + (subpath ? `/${subpath.replace(/^\//, '')}` : ``);
+}
+
+const observer = new MutationObserver((mutations) => {
+  for (const { addedNodes } of mutations) {
+    for (const node of addedNodes) {
+      if (node.nodeType === Node.ELEMENT_NODE) {
+        void discover(node as Element);
+      }
+    }
+  }
+});
+
+/**
+ * Checks a node for undefined elements and attempts to register them.
+ */
+async function discover(root: Element | ShadowRoot) {
+  if (!root) return;
+
+  const rootTagName = root instanceof Element ? root.tagName.toLowerCase() : '';
+  const rootIsBananaElement = rootTagName?.toLowerCase().startsWith('b-');
+  const rootIsCustomElement = rootTagName?.includes('-');
+
+  const tags = [...root.querySelectorAll(':not(:defined)')]
+    .map((el) => el.tagName.toLowerCase())
+    .filter((tag) => tag.startsWith('b-'));
+
+  // If the root element is an undefined Banana component, add it to the list
+  if (rootIsBananaElement && !customElements.get(rootTagName)) {
+    tags.push(rootTagName);
+  }
+
+  // Make the list unique
+  const tagsToRegister = [...new Set(tags)];
+
+  const notBananaCustomElements = [...root.querySelectorAll('*')].filter(
+    (el) => el.tagName.includes('-') && !el.tagName.toLowerCase().startsWith('b-'),
+  );
+
+  // If the root element is a custom element and not a Banana component, add it to the list
+  if (rootIsCustomElement && !rootIsBananaElement && root instanceof Element) {
+    notBananaCustomElements.push(root);
+  }
+
+  // Discover any shadow roots
+  const customElementsPromises = notBananaCustomElements.map((el) => {
+    return customElements.whenDefined(el.tagName);
+  });
+  void Promise.allSettled(customElementsPromises).then(() => {
+    notBananaCustomElements.forEach((el) => {
+      if (el.shadowRoot) void discover(el.shadowRoot);
+    });
+  });
+
+  await Promise.allSettled(tagsToRegister.map((tagName) => register(tagName)));
+}
+
+/**
+ * Registers an element by tag name.
+ */
+function register(tagName: string): Promise<void> {
+  // If the element is already defined, there's nothing more to do
+  if (customElements.get(tagName)) {
+    return Promise.resolve();
+  }
+
+  const tagWithoutPrefix = tagName.replace(/^b-/i, '');
+  const path = getBasePath(`${tagWithoutPrefix}/index.js`);
+
+  // Register it
+  return new Promise((resolve, reject) => {
+    import(path).then(() => resolve()).catch(() => reject(new Error(`Unable to autoload <${tagName}> from ${path}`)));
+  });
+}
+
+// Initial discovery
+void discover(document.body);
+
+// Listen for new undefined elements
+observer.observe(document.documentElement, { subtree: true, childList: true });
diff --git a/rollup.config.mjs b/rollup.config.mjs
index 34bc66ce..2f9d1322 100644
--- a/rollup.config.mjs
+++ b/rollup.config.mjs
@@ -42,7 +42,7 @@ const UMDName = process
   .pop()
   .replace(/(^|-)(\w)/g, (_, _$1, $2) => $2.toUpperCase());
 
-export default [
+const rollupConfig = [
   {
     input: './src/index.ts',
     output: {
@@ -105,3 +105,23 @@ export default [
     ],
   },
 ];
+
+// 如果存在./src/autoloader.ts，则添加到rollupConfig中
+if (fs.existsSync('./src/banana-autoloader.ts')) {
+  rollupConfig.push({
+    input: './src/banana-autoloader.ts',
+    output: {
+      dir: 'dist',
+      format: 'es',
+      entryFileNames: 'banana-autoloader.js',
+    },
+    plugins: [
+      typescript(),
+      nodeResolve({
+        extensions: ['.ts', '.js'],
+      }),
+    ],
+  });
+}
+
+export default rollupConfig;
diff --git a/tsconfig.json b/tsconfig.json
index b504b8d2..5a66f307 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -7,6 +7,7 @@
     "experimentalDecorators": true,
     "useDefineForClassFields": false,
     "jsx": "react-jsx",
+    "module": "esnext",
     "moduleResolution": "node",
     "baseUrl": "./",
     "paths": {