feat(compiler-sfc): introduce defineRender macro

packages/compiler-sfc/__tests__/compileScript/__snapshots__/defineRender.spec.ts.snap

@@ -0,0 +1,62 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`defineRender() > JSX Element 1`] = `
+"import { defineComponent as _defineComponent } from 'vue'
+
+export default /*#__PURE__*/_defineComponent({
+  setup(__props, { expose: __expose }) {
+  __expose();
+
+
+
+return () => <div />
+}
+
+})"
+`;
+
+exports[`defineRender() > empty argument 1`] = `
+"const foo = 'bar'
+
+export default {
+  setup(__props, { expose: __expose }) {
+  __expose();
+
+
+
+return { foo }
+}
+
+}"
+`;
+
+exports[`defineRender() > function 1`] = `
+"import { defineComponent as _defineComponent } from 'vue'
+
+export default /*#__PURE__*/_defineComponent({
+  setup(__props, { expose: __expose }) {
+  __expose();
+
+
+
+return () => <div />
+}
+
+})"
+`;
+
+exports[`defineRender() > identifier 1`] = `
+"import { defineComponent as _defineComponent } from 'vue'
+import { renderFn } from './ctx'
+
+export default /*#__PURE__*/_defineComponent({
+  setup(__props, { expose: __expose }) {
+  __expose();
+
+
+
+return renderFn
+}
+
+})"
+`;

packages/compiler-sfc/__tests__/compileScript/defineRender.spec.ts

@@ -0,0 +1,79 @@
+import { assertCode, compileSFCScript as compile } from '../utils'
+
+describe('defineRender()', () => {
+  test('JSX Element', () => {
+    const { content } = compile(
+      `
+      <script setup lang="tsx">
+      defineRender(<div />)
+      </script>
+    `,
+      { defineRender: true },
+    )
+    assertCode(content)
+    expect(content).toMatch(`return () => <div />`)
+    expect(content).not.toMatch('defineRender')
+  })
+
+  test('function', () => {
+    const { content } = compile(
+      `
+      <script setup lang="tsx">
+      defineRender(() => <div />)
+      </script>
+    `,
+      { defineRender: true },
+    )
+    assertCode(content)
+    expect(content).toMatch(`return () => <div />`)
+    expect(content).not.toMatch('defineRender')
+  })
+
+  test('identifier', () => {
+    const { content } = compile(
+      `
+      <script setup lang="ts">
+      import { renderFn } from './ctx'
+      defineRender(renderFn)
+      </script>
+    `,
+      { defineRender: true },
+    )
+    assertCode(content)
+    expect(content).toMatch(`return renderFn`)
+    expect(content).not.toMatch('defineRender')
+  })
+
+  test('empty argument', () => {
+    const { content } = compile(
+      `
+      <script setup>
+      const foo = 'bar'
+      defineRender()
+      </script>
+    `,
+      { defineRender: true },
+    )
+    assertCode(content)
+    expect(content).toMatch(`return { foo }`)
+    expect(content).not.toMatch('defineRender')
+  })
+
+  describe('errors', () => {
+    test('w/ <template>', () => {
+      expect(() =>
+        compile(
+          `
+      <script setup lang="tsx">
+      defineRender(<div />)
+      </script>
+      <template>
+        <span>hello</span>
+      </template>
+    `,
+          { defineRender: true },
+        ),
+      ).toThrow(`defineRender() cannot be used with <template>.`)
+    })
+  })
+})

packages/compiler-sfc/__tests__/utils.ts

@@ -31,6 +31,7 @@ export function assertCode(code: string) {
       plugins: [
         'typescript',
         ['importAttributes', { deprecatedAssertSyntax: true }],
+        'jsx',
       ],
     })
   } catch (e: any) {

packages/compiler-sfc/src/compileScript.ts

@@ -55,6 +55,7 @@ import { getImportedName, isCallOf, isLiteralNode } from './script/utils'
 import { analyzeScriptBindings } from './script/analyzeScriptBindings'
 import { isImportUsed } from './script/importUsageCheck'
 import { processAwait } from './script/topLevelAwait'
+import { DEFINE_RENDER, processDefineRender } from './script/defineRender'
 
 export interface SFCScriptCompileOptions {
   /**
@@ -105,6 +106,11 @@ export interface SFCScriptCompileOptions {
    * @default true
    */
   hoistStatic?: boolean
+  /**
+   * (**Experimental**) Enable macro `defineRender`
+   * @default false
+   */
+  defineRender?: boolean
   /**
    * (**Experimental**) Enable reactive destructure for `defineProps`
    * @default false
@@ -491,7 +497,8 @@ export function compileScript(
         processDefineProps(ctx, expr) ||
         processDefineEmits(ctx, expr) ||
         processDefineOptions(ctx, expr) ||
-        processDefineSlots(ctx, expr)
+        processDefineSlots(ctx, expr) ||
+        processDefineRender(ctx, expr)
       ) {
         ctx.s.remove(node.start! + startOffset, node.end! + startOffset)
       } else if (processDefineExpose(ctx, expr)) {
@@ -529,7 +536,8 @@ export function compileScript(
             !isDefineProps && processDefineEmits(ctx, init, decl.id)
           !isDefineEmits &&
             (processDefineSlots(ctx, init, decl.id) ||
-              processDefineModel(ctx, init, decl.id))
+              processDefineModel(ctx, init, decl.id) ||
+              processDefineRender(ctx, init))
 
           if (
             isDefineProps &&
@@ -797,8 +805,22 @@ export function compileScript(
   }
 
   // 9. generate return statement
-  let returned
-  if (
+  let returned = ''
+  if (ctx.renderFunction) {
+    if (sfc.template) {
+      ctx.error(
+        `${DEFINE_RENDER}() cannot be used with <template>.`,
+        ctx.renderFunction,
+      )
+    }
+    if (ctx.renderFunction.type === 'JSXElement') {
+      returned = '() => '
+    }
+    returned += scriptSetup.content.slice(
+      ctx.renderFunction.start!,
+      ctx.renderFunction.end!,
+    )
+  } else if (
     !options.inlineTemplate ||
     (!sfc.template && ctx.hasDefaultExportRender)
   ) {
@@ -837,66 +859,59 @@ export function compileScript(
       }
     }
     returned = returned.replace(/, $/, '') + ` }`
-  } else {
+  } else if (sfc.template && !sfc.template.src) {
     // inline mode
-    if (sfc.template && !sfc.template.src) {
-      if (options.templateOptions && options.templateOptions.ssr) {
-        hasInlinedSsrRenderFn = true
-      }
-      // inline render function mode - we are going to compile the template and
-      // inline it right here
-      const { code, ast, preamble, tips, errors } = compileTemplate({
-        filename,
-        ast: sfc.template.ast,
-        source: sfc.template.content,
-        inMap: sfc.template.map,
-        ...options.templateOptions,
-        id: scopeId,
-        scoped: sfc.styles.some(s => s.scoped),
-        isProd: options.isProd,
-        ssrCssVars: sfc.cssVars,
-        compilerOptions: {
-          ...(options.templateOptions &&
-            options.templateOptions.compilerOptions),
-          inline: true,
-          isTS: ctx.isTS,
-          bindingMetadata: ctx.bindingMetadata,
-        },
-      })
-      if (tips.length) {
-        tips.forEach(warnOnce)
-      }
-      const err = errors[0]
-      if (typeof err === 'string') {
-        throw new Error(err)
-      } else if (err) {
-        if (err.loc) {
-          err.message +=
-            `\n\n` +
-            sfc.filename +
-            '\n' +
-            generateCodeFrame(
-              source,
-              err.loc.start.offset,
-              err.loc.end.offset,
-            ) +
-            `\n`
-        }
-        throw err
-      }
-      if (preamble) {
-        ctx.s.prepend(preamble)
-      }
-      // avoid duplicated unref import
-      // as this may get injected by the render function preamble OR the
-      // css vars codegen
-      if (ast && ast.helpers.has(UNREF)) {
-        ctx.helperImports.delete('unref')
+    if (options.templateOptions && options.templateOptions.ssr) {
+      hasInlinedSsrRenderFn = true
+    }
+    // inline render function mode - we are going to compile the template and
+    // inline it right here
+    const { code, ast, preamble, tips, errors } = compileTemplate({
+      filename,
+      ast: sfc.template.ast,
+      source: sfc.template.content,
+      inMap: sfc.template.map,
+      ...options.templateOptions,
+      id: scopeId,
+      scoped: sfc.styles.some(s => s.scoped),
+      isProd: options.isProd,
+      ssrCssVars: sfc.cssVars,
+      compilerOptions: {
+        ...(options.templateOptions && options.templateOptions.compilerOptions),
+        inline: true,
+        isTS: ctx.isTS,
+        bindingMetadata: ctx.bindingMetadata,
+      },
+    })
+    if (tips.length) {
+      tips.forEach(warnOnce)
+    }
+    const err = errors[0]
+    if (typeof err === 'string') {
+      throw new Error(err)
+    } else if (err) {
+      if (err.loc) {
+        err.message +=
+          `\n\n` +
+          sfc.filename +
+          '\n' +
+          generateCodeFrame(source, err.loc.start.offset, err.loc.end.offset) +
+          `\n`
       }
-      returned = code
-    } else {
-      returned = `() => {}`
+      throw err
     }
+    if (preamble) {
+      ctx.s.prepend(preamble)
+    }
+    // avoid duplicated unref import
+    // as this may get injected by the render function preamble OR the
+    // css vars codegen
+    if (ast && ast.helpers.has(UNREF)) {
+      ctx.helperImports.delete('unref')
+    }
+    returned = code
+  } else {
+    returned = `() => {}`
   }
 
   if (!options.inlineTemplate && !__TEST__) {

packages/compiler-sfc/src/script/context.ts

@@ -36,6 +36,7 @@ export class ScriptCompileContext {
   hasDefaultExportRender = false
   hasDefineOptionsCall = false
   hasDefineSlotsCall = false
+  hasDefineRenderCall = false
   hasDefineModelCall = false
 
   // defineProps
@@ -59,6 +60,9 @@ export class ScriptCompileContext {
   // defineOptions
   optionsRuntimeDecl: Node | undefined
 
+  // defineRender
+  renderFunction?: Node
+
   // codegen
   bindingMetadata: BindingMetadata = {}
   helperImports: Set<string> = new Set()

packages/compiler-sfc/src/script/defineRender.ts

@@ -0,0 +1,34 @@
+import type { Node } from '@babel/types'
+import { isCallOf } from './utils'
+import type { ScriptCompileContext } from './context'
+import { warnOnce } from '../warn'
+
+export const DEFINE_RENDER = 'defineRender'
+
+export function processDefineRender(
+  ctx: ScriptCompileContext,
+  node: Node,
+): boolean {
+  if (!isCallOf(node, DEFINE_RENDER)) {
+    return false
+  }
+
+  if (!ctx.options.defineRender) {
+    warnOnce(
+      `${DEFINE_RENDER}() is an experimental feature and disabled by default.\n` +
+        `To enable it, follow the RFC at https://github.com/vuejs/rfcs/discussions/585.`,
+    )
+    return false
+  }
+
+  if (ctx.hasDefineRenderCall) {
+    ctx.error(`duplicate ${DEFINE_RENDER}() call`, node)
+  }
+
+  ctx.hasDefineRenderCall = true
+  if (node.arguments.length > 0) {
+    ctx.renderFunction = node.arguments[0]
+  }
+
+  return true
+}