Revert "one more tweak for babel macro"

This reverts commit ae36dfe.

Author: Evan Jacobs

src/utils/detectors.js

@@ -21,10 +21,11 @@ export const importLocalName = (name, state, options = {}) => {
   const cacheKeyAffix = cacheIdentifier ? `|${cacheIdentifier}` : ''
   const cacheKey = name + state.file.opts.filename + cacheKeyAffix
 
-  if (state.customImportName && !localNameCache[cacheKey]) {
-    return state.customImportName.name
-  } else if (!bypassCache && localNameCache[cacheKey]) {
+  if (!bypassCache && cacheKey in localNameCache) {
     return localNameCache[cacheKey]
+    // state.customImportName is injected by the babel macro
+  } else if (state.customImportName) {
+    return state.customImportName.name
   }
 
   let localName = state.styledRequired

src/visitors/transpileCssProp.js

@@ -44,12 +44,14 @@ export default t => (path, state) => {
 
   const program = state.file.path
 
-  let importName = importLocalName('default', state)
+  // state.customImportName is passed through from styled-components/macro if it's used
+  // since the macro also inserts the import
+  let importName = state.customImportName || importLocalName('default', state)
 
   const { bindings } = program.scope
 
   // Insert import if it doesn't exist yet
-  if (!importName) {
+  if (!importName || !bindings[importName.name] || !bindings[importName]) {
     addDefault(path, 'styled-components', {
       nameHint: 'styled',
     })