transform-spread: create TS types (not Flow) when using TS (#11378)

* ➕ add test fixture

* ➕ add removeTypeDuplicates for typescript

* ➕ add createTSUnionType for typescript

* 💊 fix ConditionalExpression for typescript

* 💊 fix ConditionalExpression

* 💊 fix added test case

* ➕ add new line at the end of the file

* 💊 types.every(f) => f(types[0])

* 🔄 bug => foo

* ➕ add TSBaseType

* ➕ add conditions NOT to break backward compatibility

packages/babel-traverse/src/path/inference/inferer-reference.js

@@ -91,9 +91,15 @@ function getTypeAnnotationBindingConstantViolations(binding, path, name) {
     }
   }
 
-  if (types.length) {
-    return t.createUnionTypeAnnotation(types);
+  if (!types.length) {
+    return;
   }
+
+  if (t.isTSTypeAnnotation(types[0]) && t.createTSUnionType) {
+    return t.createTSUnionType(types);
+  }
+
+  return t.createUnionTypeAnnotation(types);
 }
 
 function getConstantViolationsBefore(binding, path, functions) {
@@ -201,6 +207,13 @@ function getConditionalAnnotation(binding, path, name) {
   }
 
   if (types.length) {
+    if (t.isTSTypeAnnotation(types[0]) && t.createTSUnionType) {
+      return {
+        typeAnnotation: t.createTSUnionType(types),
+        ifStatement,
+      };
+    }
+
     return {
       typeAnnotation: t.createUnionTypeAnnotation(types),
       ifStatement,