Fix String8::operator+

The LHS was ignored when using:
  String8 + String8
  String8 + (const char*)

Add unit tests for above.

Bug: 2898473
Change-Id: Ic8fe7be668b665c36aaaa3fc3c3ffdfff0fbba25

2 files changed, 78 insertions, 2 deletions

diff --git a/libs/utils/tests/Android.mk b/libs/utils/tests/Android.mk
index b9f206a..725de9c 100644
--- a/libs/utils/tests/Android.mk
+++ b/libs/utils/tests/Android.mk
@@ -7,7 +7,8 @@ ifneq ($(TARGET_SIMULATOR),true)
 # Build the unit tests.
 test_src_files := \
 	ObbFile_test.cpp \
-	PollLoop_test.cpp
+	PollLoop_test.cpp \
+	String8_test.cpp
 
 shared_libraries := \
 	libz \
@@ -41,4 +42,4 @@ $(foreach file,$(test_src_files), \
     $(eval include $(BUILD_EXECUTABLE)) \
 )
 
-endif
\ No newline at end of file
+endif
diff --git a/libs/utils/tests/String8_test.cpp b/libs/utils/tests/String8_test.cpp
new file mode 100644
index 0000000..c42c68d
--- /dev/null
+++ b/libs/utils/tests/String8_test.cpp
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "String8_test"
+#include <utils/Log.h>
+#include <utils/String8.h>
+
+#include <gtest/gtest.h>
+
+namespace android {
+
+class String8Test : public testing::Test {
+protected:
+    virtual void SetUp() {
+    }
+
+    virtual void TearDown() {
+    }
+};
+
+TEST_F(String8Test, Cstr) {
+    String8 tmp("Hello, world!");
+
+    EXPECT_STREQ(tmp.string(), "Hello, world!");
+}
+
+TEST_F(String8Test, OperatorPlus) {
+    String8 src1("Hello, ");
+
+    // Test adding String8 + const char*
+    const char* ccsrc2 = "world!";
+    String8 dst1 = src1 + ccsrc2;
+    EXPECT_STREQ(dst1.string(), "Hello, world!");
+    EXPECT_STREQ(src1.string(), "Hello, ");
+    EXPECT_STREQ(ccsrc2, "world!");
+
+    // Test adding String8 + String8
+    String8 ssrc2("world!");
+    String8 dst2 = src1 + ssrc2;
+    EXPECT_STREQ(dst2.string(), "Hello, world!");
+    EXPECT_STREQ(src1.string(), "Hello, ");
+    EXPECT_STREQ(ssrc2.string(), "world!");
+}
+
+TEST_F(String8Test, OperatorPlusEquals) {
+    String8 src1("My voice");
+
+    // Testing String8 += String8
+    String8 src2(" is my passport.");
+    src1 += src2;
+    EXPECT_STREQ(src1.string(), "My voice is my passport.");
+    EXPECT_STREQ(src2.string(), " is my passport.");
+
+    // Adding const char* to the previous string.
+    const char* src3 = " Verify me.";
+    src1 += src3;
+    EXPECT_STREQ(src1.string(), "My voice is my passport. Verify me.");
+    EXPECT_STREQ(src2.string(), " is my passport.");
+    EXPECT_STREQ(src3, " Verify me.");
+}
+
+}