fix(ssr/sfc-css-vars): fix v-bind css vars codegen for SSR

fix #5443
close #5444

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

@@ -1039,8 +1039,7 @@ return (_ctx, _cache) => {
 `;
 
 exports[`SFC compile <script setup> inlineTemplate mode ssr codegen 1`] = `
-"import { useCssVars as _useCssVars, unref as _unref } from 'vue'
-import { ssrRenderAttrs as _ssrRenderAttrs, ssrInterpolate as _ssrInterpolate } from \\"vue/server-renderer\\"
+"import { ssrRenderAttrs as _ssrRenderAttrs, ssrInterpolate as _ssrInterpolate } from \\"vue/server-renderer\\"
 
 import { ref } from 'vue'
         
@@ -1048,15 +1047,11 @@ export default {
   __ssrInlineRender: true,
   setup(__props) {
 
-_useCssVars(_ctx => ({
-  \\"xxxxxxxx-count\\": (count.value)
-}))
-
         const count = ref(0)
         
 return (_ctx, _push, _parent, _attrs) => {
   const _cssVars = { style: {
-  \\"xxxxxxxx-count\\": (count.value)
+  \\"--xxxxxxxx-count\\": (count.value)
 }}
   _push(\`<!--[--><div\${
     _ssrRenderAttrs(_cssVars)

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

@@ -1,5 +1,5 @@
 import { BindingTypes } from '@vue/compiler-core'
-import { compileSFCScript as compile, assertCode } from './utils'
+import { compileSFCScript as compile, assertCode, mockId } from './utils'
 
 describe('SFC compile <script setup>', () => {
   test('should expose top level declarations', () => {
@@ -726,6 +726,8 @@ defineExpose({ foo: 123 })
       expect(content).toMatch(`\n  __ssrInlineRender: true,\n`)
       expect(content).toMatch(`return (_ctx, _push`)
       expect(content).toMatch(`ssrInterpolate`)
+      expect(content).not.toMatch(`useCssVars`)
+      expect(content).toMatch(`"--${mockId}-count": (count.value)`)
       assertCode(content)
     })
   })

packages/compiler-sfc/src/compileScript.ts

@@ -432,7 +432,8 @@ export function compileScript(
               )
             }
 
-            const propKey = prop.key.type === 'StringLiteral'
+            const propKey =
+              prop.key.type === 'StringLiteral'
                 ? prop.key.value
                 : (prop.key as Identifier).name
 
@@ -1304,7 +1305,11 @@ export function compileScript(
   }
 
   // 8. inject `useCssVars` calls
-  if (cssVars.length) {
+  if (
+    cssVars.length &&
+    // no need to do this when targeting SSR
+    !(options.inlineTemplate && options.templateOptions?.ssr)
+  ) {
     helperImports.add(CSS_VARS_HELPER)
     helperImports.add('unref')
     s.prependRight(

packages/compiler-sfc/src/compileTemplate.ts

@@ -202,7 +202,7 @@ function doCompileTemplate({
     cacheHandlers: true,
     ssrCssVars:
       ssr && ssrCssVars && ssrCssVars.length
-        ? genCssVarsFromList(ssrCssVars, shortId, isProd)
+        ? genCssVarsFromList(ssrCssVars, shortId, isProd, true)
         : '',
     scopeId: scoped ? longId : undefined,
     slotted,

packages/compiler-sfc/src/cssVars.ts

@@ -18,10 +18,13 @@ const cssVarRE = /v-bind\s*\(((?:[^)(]+|\((?:[^)(]+|\([^)(]*\))*\))*)\)/g
 export function genCssVarsFromList(
   vars: string[],
   id: string,
-  isProd: boolean
+  isProd: boolean,
+  isSSR = false
 ): string {
   return `{\n  ${vars
-    .map(key => `"${genVarName(id, key, isProd)}": (${key})`)
+    .map(
+      key => `"${isSSR ? `--` : ``}${genVarName(id, key, isProd)}": (${key})`
+    )
     .join(',\n  ')}\n}`
 }