1 files changed, 53 insertions, 0 deletions
diff --git a/llvm/unittests/Support/ErrorTest.cpp b/llvm/unittests/Support/ErrorTest.cpp
index 852753f..db332eb 100644
--- a/llvm/unittests/Support/ErrorTest.cpp
+++ b/llvm/unittests/Support/ErrorTest.cpp
@@ -605,6 +605,59 @@ TEST(Error, ExpectedCovariance) {
   (void)!!A2;
 }
 
+// Test that handleExpected just returns success values.
+TEST(Error, HandleExpectedSuccess) {
+  auto ValOrErr =
+    handleExpected(Expected<int>(42),
+                   []() { return Expected<int>(43); });
+  EXPECT_TRUE(!!ValOrErr)
+    << "handleExpected should have returned a success value here";
+  EXPECT_EQ(*ValOrErr, 42)
+    << "handleExpected should have returned the original success value here";
+}
+
+enum FooStrategy { Aggressive, Conservative };
+
+static Expected<int> foo(FooStrategy S) {
+  if (S == Aggressive)
+    return make_error<CustomError>(7);
+  return 42;
+}
+
+// Test that handleExpected invokes the error path if errors are not handled.
+TEST(Error, HandleExpectedUnhandledError) {
+  // foo(Aggressive) should return a CustomError which should pass through as
+  // there is no handler for CustomError.
+  auto ValOrErr =
+    handleExpected(
+      foo(Aggressive),
+      []() { return foo(Conservative); });
+
+  EXPECT_FALSE(!!ValOrErr)
+    << "handleExpected should have returned an error here";
+  auto Err = ValOrErr.takeError();
+  EXPECT_TRUE(Err.isA<CustomError>())
+    << "handleExpected should have returned the CustomError generated by "
+    "foo(Aggressive) here";
+  consumeError(std::move(Err));
+}
+
+// Test that handleExpected invokes the fallback path if errors are handled.
+TEST(Error, HandleExpectedHandledError) {
+  // foo(Aggressive) should return a CustomError which should handle triggering
+  // the fallback path.
+  auto ValOrErr =
+    handleExpected(
+      foo(Aggressive),
+      []() { return foo(Conservative); },
+      [](const CustomError&) { /* do nothing */ });
+
+  EXPECT_TRUE(!!ValOrErr)
+    << "handleExpected should have returned a success value here";
+  EXPECT_EQ(*ValOrErr, 42)
+    << "handleExpected returned the wrong success value";
+}
+
 TEST(Error, ErrorCodeConversions) {
   // Round-trip a success value to check that it converts correctly.
   EXPECT_EQ(errorToErrorCode(errorCodeToError(std::error_code())),