Merge pull request #10696 from xedin/rdar-32241441

Author: swift-ci

lib/Sema/TypeCheckPattern.cpp

@@ -1402,8 +1402,17 @@ bool TypeChecker::coercePatternToType(Pattern *&P, DeclContext *dc, Type type,
             goto recur;
           }
 
-          diagnose(EEP->getLoc(), diag::enum_element_pattern_member_not_found,
-                   EEP->getName().str(), type);
+          auto diag = diagnose(EEP->getLoc(),
+                               diag::enum_element_pattern_member_not_found,
+                               EEP->getName().str(), type);
+
+          // If we have an optional type let's try to see if the case
+          // exists in its base type, if so we can suggest a fix-it for that.
+          if (auto baseType = type->getOptionalObjectType()) {
+            if (lookupEnumMemberElement(*this, dc, baseType, EEP->getName(),
+                                        EEP->getLoc()))
+              diag.fixItInsertAfter(EEP->getEndLoc(), "?");
+          }
         }
         return true;
       }

test/Constraints/patterns.swift

@@ -314,3 +314,25 @@ switch staticMembers {
 }
 
 _ = 0
+
+// rdar://problem/32241441 - Add fix-it for cases in switch with optional chaining
+
+struct S_32241441 {
+  enum E_32241441 {
+    case foo
+    case bar
+  }
+
+  var type: E_32241441 = E_32241441.foo
+}
+
+func rdar32241441() {
+  let s: S_32241441? = S_32241441()
+
+  switch s?.type {
+  case .foo: // expected-error {{enum case 'foo' not found in type 'S_32241441.E_32241441?'}} {{12-12=?}}
+    break;
+  case .bar: // expected-error {{enum case 'bar' not found in type 'S_32241441.E_32241441?'}} {{12-12=?}}
+    break;
+  }
+}