Factoring GUID generation from metrics to base

base/rand_util_unittest.cc

Index: base/rand_util_unittest.cc
diff --git a/base/rand_util_unittest.cc b/base/rand_util_unittest.cc
index cbc338a3b4eec23299af3c4a7d97082ed60904d0..112099f09e17020baff62657f96b5f4a88b53bfb 100644
--- a/base/rand_util_unittest.cc
+++ b/base/rand_util_unittest.cc
@@ -35,3 +35,50 @@ TEST(RandUtilTest, RandGeneratorForRandomShuffle) {
   EXPECT_LE(std::numeric_limits<ptrdiff_t>::max(),
             std::numeric_limits<int64>::max());
 }
+
+#if defined(OS_POSIX)
+// For unit testing purposes only.  Do not use outside of tests.
+namespace base {
+extern std::string RandomBytesToGUIDString(const uint64 bytes[2]);
+}  // base
+
+TEST(RandUtilTest, GUIDGeneratesAllZeroes) {
+  uint64 bytes[] = { 0, 0 };
+  std::string clientid = base::RandomBytesToGUIDString(bytes);
+  EXPECT_EQ("00000000-0000-0000-0000-000000000000", clientid);
+}
+
+TEST(RandUtilTest, GUIDGeneratesCorrectly) {
+  uint64 bytes[] = { 0x0123456789ABCDEFULL, 0xFEDCBA9876543210ULL };
+  std::string clientid = base::RandomBytesToGUIDString(bytes);
+  EXPECT_EQ("01234567-89AB-CDEF-FEDC-BA9876543210", clientid);
+}
+#endif
+
+TEST(RandUtilTest, GUIDCorrectlyFormatted) {
+  const int kIterations = 10;
+  for (int it = 0; it < kIterations; ++it) {
+    std::string guid = base::GenerateGUID();
+    EXPECT_EQ(36U, guid.length());
+    std::string hexchars = "0123456789ABCDEF";
+    for (uint32 i = 0; i < guid.length(); ++i) {
+      char current = guid.at(i);
+      if (i == 8 || i == 13 || i == 18 || i == 23) {
+        EXPECT_EQ('-', current);
+      } else {
+        EXPECT_TRUE(std::string::npos != hexchars.find(current));
+      }
+    }
+  }
+}
+
+TEST(RandUtilTest, GUIDBasicUniqueness) {
+  const int kIterations = 10;
+  for (int it = 0; it < kIterations; ++it) {
+    std::string guid1 = base::GenerateGUID();
+    std::string guid2 = base::GenerateGUID();
+    EXPECT_EQ(36U, guid1.length());
+    EXPECT_EQ(36U, guid2.length());
+    EXPECT_NE(guid1, guid2);
+  }
+}