chore: mark slotflag and fix some bugs (#45)

* fix: reassign variable as component should work

* feat: remove `compatibleProps`

* feat: mark slotFlag

* chore: istanbul ignore in babel.config.js

* test: reassign variable as component should work

Author: Amour1688

packages/babel-plugin-jsx/babel.config.js

@@ -1,3 +1,4 @@
+/* istanbul ignore next */
 module.exports = {
   presets: [
     '@babel/preset-env',

packages/babel-plugin-jsx/src/buildProps.ts

@@ -14,6 +14,7 @@ import parseDirectives from './parseDirectives';
 import { PatchFlags } from './patchFlags';
 import { State, ExcludesBoolean } from '.';
 import { transformJSXElement } from './transform-vue-jsx';
+import SlotFlags from './slotFlags';
 
 const xlinkRE = /^xlink([A-Z])/;
 const onRE = /^on[^a-z]/;
@@ -51,7 +52,7 @@ const transformJSXSpreadAttribute = (
   const { properties } = argument.node;
   if (!properties) {
     if (argument.isIdentifier()) {
-      walksScope(nodePath, (argument.node as t.Identifier).name);
+      walksScope(nodePath, (argument.node as t.Identifier).name, SlotFlags.DYNAMIC);
     }
     mergeArgs.push(argument.node);
   } else {
@@ -173,8 +174,8 @@ const buildProps = (path: NodePath<t.JSXElement>, state: State) => {
             hasStyleBinding = true;
           } else if (
             name !== 'key'
-            && !isDirective(name)
-            && name !== 'on'
+              && !isDirective(name)
+              && name !== 'on'
           ) {
             dynamicPropNames.add(name);
           }

packages/babel-plugin-jsx/src/index.ts

@@ -10,7 +10,6 @@ export type State = {
 
 interface Opts {
   transformOn?: boolean;
-  compatibleProps?: boolean;
   optimize?: boolean;
   isCustomElement?: (tag: string) => boolean;
 }

packages/babel-plugin-jsx/src/slotFlags.ts

@@ -0,0 +1,24 @@
+// https://github.com/vuejs/vue-next/blob/master/packages/shared/src/slotFlags.ts
+const enum SlotFlags {
+  /**
+   * Stable slots that only reference slot props or context state. The slot
+   * can fully capture its own dependencies so when passed down the parent won't
+   * need to force the child to update.
+   */
+  STABLE = 1,
+  /**
+   * Slots that reference scope variables (v-for or an outer slot prop), or
+   * has conditional structure (v-if, v-for). The parent will need to force
+   * the child to update because the slot does not fully capture its dependencies.
+   */
+  DYNAMIC = 2,
+  /**
+   * `<slot/>` being forwarded into a child component. Whether the parent needs
+   * to update the child is dependent on what kind of slots the parent itself
+   * received. This has to be refined at runtime, when the child's vnode
+   * is being created (in `normalizeChildren`)
+   */
+  FORWARDED = 3
+}
+
+export default SlotFlags;

packages/babel-plugin-jsx/src/transform-vue-jsx.ts

@@ -1,16 +1,17 @@
 import * as t from '@babel/types';
 import { NodePath } from '@babel/traverse';
-import { addDefault, addNamespace } from '@babel/helper-module-imports';
+import { addNamespace } from '@babel/helper-module-imports';
 import {
   createIdentifier,
   transformJSXSpreadChild,
   transformJSXText,
   transformJSXExpressionContainer,
   walksScope,
+  buildIIFE,
 } from './utils';
 import buildProps from './buildProps';
-import { PatchFlags } from './patchFlags';
-import { State, ExcludesBoolean } from '.';
+import SlotFlags from './slotFlags';
+import { State } from '.';
 
 /**
  * Get children from Array of JSX children
@@ -42,7 +43,7 @@ const getChildren = (
         const { name } = expression as t.Identifier;
         const { referencePaths = [] } = path.scope.getBinding(name) || {};
         referencePaths.forEach((referencePath) => {
-          walksScope(referencePath, name);
+          walksScope(referencePath, name, SlotFlags.DYNAMIC);
         });
       }
 
@@ -79,45 +80,39 @@ const transformJSXElement = (
     slots,
   } = buildProps(path, state);
 
-  const useOptimate = path.getData('optimize') !== false;
+  const { optimize = false } = state.opts;
 
-  const { compatibleProps = false, optimize = false } = state.opts;
-  if (compatibleProps && !state.get('compatibleProps')) {
-    state.set('compatibleProps', addDefault(
-      path, '@ant-design-vue/babel-helper-vue-compatible-props', { nameHint: '_compatibleProps' },
-    ));
-  }
+  const slotFlag = path.getData('slotFlag') || SlotFlags.STABLE;
 
   // @ts-ignore
-  const createVNode = t.callExpression(createIdentifier(state, optimize ? 'createVNode' : 'h'), [
+  const createVNode = t.callExpression(createIdentifier(state, 'createVNode'), [
     tag,
-    // @ts-ignore
-    compatibleProps ? t.callExpression(state.get('compatibleProps'), [props]) : props,
+    props,
     (children.length || slots) ? (
       isComponent
         ? t.objectExpression([
           !!children.length && t.objectProperty(
             t.identifier('default'),
-            t.arrowFunctionExpression([], t.arrayExpression(children)),
+            t.arrowFunctionExpression([], t.arrayExpression(buildIIFE(path, children))),
           ),
           ...(slots ? (
             t.isObjectExpression(slots)
               ? (slots! as t.ObjectExpression).properties
               : [t.spreadElement(slots!)]
           ) : []),
-        ].filter(Boolean as any as ExcludesBoolean))
+          optimize && t.objectProperty(
+            t.identifier('_'),
+            t.numericLiteral(slotFlag),
+          ),
+        ].filter(Boolean as any))
         : t.arrayExpression(children)
     ) : t.nullLiteral(),
-    !!patchFlag && optimize && (
-      useOptimate
-        ? t.numericLiteral(patchFlag)
-        : t.numericLiteral(PatchFlags.BAIL)
-    ),
+    !!patchFlag && optimize && t.numericLiteral(patchFlag),
     !!dynamicPropNames.size && optimize
     && t.arrayExpression(
       [...dynamicPropNames.keys()].map((name) => t.stringLiteral(name as string)),
     ),
-  ].filter(Boolean as any as ExcludesBoolean));
+  ].filter(Boolean as any));
 
   if (!directives.length) {
     return createVNode;

packages/babel-plugin-jsx/src/utils.ts

@@ -3,6 +3,7 @@ import htmlTags from 'html-tags';
 import svgTags from 'svg-tags';
 import { NodePath } from '@babel/traverse';
 import { State } from '.';
+import SlotFlags from './slotFlags';
 
 /**
  * create Identifier
@@ -181,15 +182,50 @@ const transformJSXSpreadChild = (
   path: NodePath<t.JSXSpreadChild>,
 ): t.SpreadElement => t.spreadElement(path.get('expression').node);
 
-const walksScope = (path: NodePath, name: string): void => {
+const walksScope = (path: NodePath, name: string, slotFlag: SlotFlags): void => {
   if (path.scope.hasBinding(name) && path.parentPath) {
     if (t.isJSXElement(path.parentPath.node)) {
-      path.parentPath.setData('optimize', false);
+      path.parentPath.setData('slotFlag', slotFlag);
     }
-    walksScope(path.parentPath, name);
+    walksScope(path.parentPath, name, slotFlag);
   }
 };
 
+const createInsertName = (path: NodePath, name: string): t.Identifier => {
+  if (path.scope.hasBinding(name)) {
+    return createInsertName(path, `_${name}`);
+  }
+  return t.identifier(name);
+};
+
+const buildIIFE = (path: NodePath<t.JSXElement>, children: t.Expression[]) => {
+  const { parentPath } = path;
+  if (t.isAssignmentExpression(parentPath)) {
+    const { left } = parentPath.node as t.AssignmentExpression;
+    if (t.isIdentifier(left)) {
+      return children.map((child) => {
+        if (t.isIdentifier(child) && child.name === left.name) {
+          const insertName = createInsertName(parentPath, `_${child.name}`);
+          parentPath.insertBefore(
+            t.variableDeclaration('const', [
+              t.variableDeclarator(
+                insertName,
+                t.callExpression(
+                  t.functionExpression(null, [], t.blockStatement([t.returnStatement(child)])),
+                  [],
+                ),
+              ),
+            ]),
+          );
+          return insertName;
+        }
+        return child;
+      });
+    }
+  }
+  return children;
+};
+
 export {
   createIdentifier,
   isDirective,
@@ -202,4 +238,5 @@ export {
   transformJSXExpressionContainer,
   isFragment,
   walksScope,
+  buildIIFE,
 };

packages/babel-plugin-jsx/test/index.test.tsx

@@ -469,3 +469,30 @@ describe('variables outside slots', () => {
     expect(wrapper.get('#textarea').element.innerHTML).toBe('1');
   });
 });
+
+test('reassign variable as component should work', () => {
+  let a: any = 1;
+
+  const A = defineComponent({
+    setup(_, { slots }) {
+      return () => <span>{slots.default!()}</span>;
+    },
+  });
+
+  /* eslint-disable */
+  // @ts-ignore
+  const _a = 1;
+  // @ts-ignore
+  const __a = 2;
+  /* eslint-enable */
+
+  a = <A>{a}</A>;
+
+  const wrapper = mount({
+    render() {
+      return a;
+    },
+  });
+
+  expect(wrapper.html()).toBe('<span>1</span>');
+});

packages/jsx-explorer/src/index.ts

@@ -63,7 +63,7 @@ const compile = () => {
   console.clear();
   transform(src, {
     babelrc: false,
-    plugins: [[babelPluginJSx, { transformOn: true }]],
+    plugins: [[babelPluginJSx, { transformOn: true, optimize: true }]],
     ast: true,
   }, (err, result = {}) => {
     const res = result!;
@@ -87,18 +87,17 @@ compile();
 // update compile output when input changes
 editor.onDidChangeModelContent(debounce(compile));
 
-function debounce<T extends (...args: any[]) => any>(
+function debounce<T extends(...args: any[]) => any>(
   fn: T,
-  delay: number = 300
-): T {
-  let prevTimer: number | null = null
+  delay = 300): T {
+  let prevTimer: number | null = null;
   return ((...args: any[]) => {
     if (prevTimer) {
-      clearTimeout(prevTimer)
+      clearTimeout(prevTimer);
     }
     prevTimer = window.setTimeout(() => {
-      fn(...args)
-      prevTimer = null
-    }, delay)
-  }) as any
+      fn(...args);
+      prevTimer = null;
+    }, delay);
+  }) as any;
 }