feat(sfc): css modules support

packages/runtime-core/src/helpers/useCssModule.ts

@@ -0,0 +1,23 @@
+import { getCurrentInstance } from '../component'
+import { EMPTY_OBJ } from '@vue/shared'
+import { warn } from '../warning'
+
+export function useCSSModule(name = '$style'): Record<string, string> {
+  const instance = getCurrentInstance()!
+  if (!instance) {
+    __DEV__ && warn(`useCSSModule must be called inside setup()`)
+    return EMPTY_OBJ
+  }
+  const modules = instance.type.__cssModules
+  if (!modules) {
+    __DEV__ && warn(`Current instance does not have CSS modules injected.`)
+    return EMPTY_OBJ
+  }
+  const mod = modules[name]
+  if (!mod) {
+    __DEV__ &&
+      warn(`Current instance does not have CSS module named "${name}".`)
+    return EMPTY_OBJ
+  }
+  return mod as Record<string, string>
+}