From 2349dc1a21a9f82943532214f4e1189af1d33c16 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Thu, 15 Aug 2019 14:07:23 +0200
Subject: [PATCH] StringView: Add StringView::operator==(StringView)

Previously we'd implicitly convert the second StringView to a String
when comparing two StringViews, which is obviously not what we wanted.
---
 AK/StringView.h             | 16 ++++++++++++++++
 AK/Tests/Makefile           |  4 +++-
 AK/Tests/TestStringView.cpp | 36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 AK/Tests/TestStringView.cpp

diff --git a/AK/StringView.h b/AK/StringView.h
index 7d5d50a99f1..7fceb768857 100644
--- a/AK/StringView.h
+++ b/AK/StringView.h
@@ -83,6 +83,22 @@ public:
 
     bool operator==(const String&) const;
 
+    bool operator==(const StringView& other) const
+    {
+        if (is_null())
+            return other.is_null();
+        if (other.is_null())
+            return false;
+        if (length() != other.length())
+            return false;
+        return !memcmp(m_characters, other.m_characters, m_length);
+    }
+
+    bool operator!=(const StringView& other) const
+    {
+        return !(*this == other);
+    }
+
 private:
     friend class String;
     const StringImpl* m_impl { nullptr };
diff --git a/AK/Tests/Makefile b/AK/Tests/Makefile
index b1c7b8a2488..a87819f174c 100644
--- a/AK/Tests/Makefile
+++ b/AK/Tests/Makefile
@@ -1,4 +1,4 @@
-PROGRAMS = TestString TestQueue TestVector TestHashMap TestJSON TestWeakPtr TestNonnullRefPtr TestRefPtr TestFixedArray TestFileSystemPath TestURL
+PROGRAMS = TestString TestQueue TestVector TestHashMap TestJSON TestWeakPtr TestNonnullRefPtr TestRefPtr TestFixedArray TestFileSystemPath TestURL TestStringView
 
 CXXFLAGS = -std=c++17 -Wall -Wextra -ggdb3 -O2 -I../ -I../../
 
@@ -62,6 +62,8 @@ TestFileSystemPath: TestFileSystemPath.o $(SHARED_TEST_OBJS)
 TestURL: TestURL.o $(SHARED_TEST_OBJS)
 	$(PRE_CXX) $(CXX) $(CXXFLAGS) -o $@ TestURL.o $(SHARED_TEST_OBJS)
 
+TestStringView: TestStringView.o $(SHARED_TEST_OBJS)
+	$(PRE_CXX) $(CXX) $(CXXFLAGS) -o $@ TestStringView.o $(SHARED_TEST_OBJS)
 
 clean:
 	rm -f $(SHARED_TEST_OBJS)
diff --git a/AK/Tests/TestStringView.cpp b/AK/Tests/TestStringView.cpp
new file mode 100644
index 00000000000..06c2c565898
--- /dev/null
+++ b/AK/Tests/TestStringView.cpp
@@ -0,0 +1,36 @@
+#include <AK/TestSuite.h>
+
+#include <AK/AKString.h>
+
+TEST_CASE(construct_empty)
+{
+    EXPECT(StringView().is_null());
+    EXPECT(StringView().is_empty());
+    EXPECT(!StringView().characters_without_null_termination());
+    EXPECT_EQ(StringView().length(), 0);
+}
+
+TEST_CASE(view_literal)
+{
+    const char* truth = "cats rule dogs drool";
+    StringView view(truth);
+    EXPECT_EQ(view.is_null(), false);
+    EXPECT_EQ(view.characters_without_null_termination(), truth);
+    EXPECT_EQ(view, view);
+    EXPECT_EQ(view, truth);
+}
+
+TEST_CASE(compare_views)
+{
+    String foo1 = "foo";
+    String foo2 = "foo";
+    auto view1 = foo1.view();
+    auto view2 = foo2.view();
+
+    EXPECT_EQ(view1, view2);
+    EXPECT_EQ(view1, foo1);
+    EXPECT_EQ(view1, foo2);
+    EXPECT_EQ(view1, "foo");
+}
+
+TEST_MAIN(StringView)