1 files changed, 55 insertions, 0 deletions
diff --git a/xpcom/tests/gtest/TestSubstringTuple.cpp b/xpcom/tests/gtest/TestSubstringTuple.cpp
new file mode 100644
index 0000000000..6dfd6bc154
--- /dev/null
+++ b/xpcom/tests/gtest/TestSubstringTuple.cpp
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsLiteralString.h"
+#include "nsTSubstringTuple.h"
+#include "gtest/gtest.h"
+
+namespace TestSubstringTuple {
+
+static const auto kFooLiteral = u"foo"_ns;
+
+static const auto kFoo = nsCString("foo");
+static const auto kBar = nsCString("bar");
+static const auto kBaz = nsCString("baz");
+
+// The test must be done in a macro to ensure that tuple is always a temporary.
+#define DO_SUBSTRING_TUPLE_TEST(tuple, dependentString, expectedLength, \
+                                expectedDependency)                     \
+  const auto length = (tuple).Length();                                 \
+  const auto isDependentOn = (tuple).IsDependentOn(                     \
+      dependentString.BeginReading(), dependentString.EndReading());    \
+                                                                        \
+  EXPECT_EQ((expectedLength), length);                                  \
+  EXPECT_EQ((expectedDependency), isDependentOn);                       \
+                                                                        \
+  const auto [combinedIsDependentOn, combinedLength] =                  \
+      (tuple).IsDependentOnWithLength(dependentString.BeginReading(),   \
+                                      dependentString.EndReading());    \
+                                                                        \
+  EXPECT_EQ(length, combinedLength);                                    \
+  EXPECT_EQ(isDependentOn, combinedIsDependentOn);
+
+TEST(SubstringTuple, IsDependentOnAndLength_NonDependent_Literal_ZeroLength)
+{ DO_SUBSTRING_TUPLE_TEST(u""_ns + u""_ns, kFooLiteral, 0u, false); }
+
+TEST(SubstringTuple, IsDependentOnAndLength_NonDependent_Literal_NonZeroLength)
+{ DO_SUBSTRING_TUPLE_TEST(u"bar"_ns + u"baz"_ns, kFooLiteral, 6u, false); }
+
+TEST(SubstringTuple, IsDependentOnAndLength_NonDependent_NonZeroLength)
+{ DO_SUBSTRING_TUPLE_TEST(kBar + kBaz, kFoo, 6u, false); }
+
+TEST(SubstringTuple,
+     IsDependentOnAndLength_NonDependent_NonZeroLength_ThreeParts)
+{ DO_SUBSTRING_TUPLE_TEST(kBar + kBaz + kBar, kFoo, 9u, false); }
+
+TEST(SubstringTuple, IsDependentOnAndLength_Dependent_NonZeroLength)
+{ DO_SUBSTRING_TUPLE_TEST(kBar + kBaz, kBar, 6u, true); }
+
+TEST(SubstringTuple, IsDependentOnAndLength_Dependent_NonZeroLength_ThreeParts)
+{ DO_SUBSTRING_TUPLE_TEST(kBar + kBaz + kFoo, kBar, 9u, true); }
+
+}  // namespace TestSubstringTuple