mDNS: Add Hashing Tests

Found while writing another patch that there were bugs in the existing
hash functions. This CL should fix them and add UTs for validation

Change-Id: Ifb0efd09a2bc3de7d206924e9755bafdfe887509
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/2233371
Commit-Queue: Ryan Keane <rwkeane@google.com>
Reviewed-by: Jordan Bayles <jophba@chromium.org>

2 files changed, 47 insertions, 5 deletions

diff --git a/discovery/mdns/mdns_records.h b/discovery/mdns/mdns_records.h
index b797f329..8e9ac244 100644
--- a/discovery/mdns/mdns_records.h
+++ b/discovery/mdns/mdns_records.h
@@ -13,6 +13,7 @@
 #include <utility>
 #include <vector>
 
+#include "absl/strings/ascii.h"
 #include "absl/strings/string_view.h"
 #include "absl/types/variant.h"
 #include "discovery/mdns/public/mdns_constants.h"
@@ -86,7 +87,11 @@ class DomainName {
 
   template <typename H>
   friend H AbslHashValue(H h, const DomainName& domain_name) {
-    return H::combine(std::move(h), domain_name.labels_);
+    std::vector<std::string> labels_clone = domain_name.labels_;
+    for (auto& label : labels_clone) {
+      absl::AsciiStrToLower(&label);
+    }
+    return H::combine(std::move(h), std::move(labels_clone));
   }
 
  private:
@@ -188,7 +193,8 @@ class ARecordRdata {
 
   template <typename H>
   friend H AbslHashValue(H h, const ARecordRdata& rdata) {
-    return H::combine(std::move(h), rdata.ipv4_address_.bytes());
+    const auto& bytes = rdata.ipv4_address_.bytes();
+    return H::combine_contiguous(std::move(h), bytes, 4);
   }
 
  private:
@@ -217,7 +223,8 @@ class AAAARecordRdata {
 
   template <typename H>
   friend H AbslHashValue(H h, const AAAARecordRdata& rdata) {
-    return H::combine(std::move(h), rdata.ipv6_address_.bytes());
+    const auto& bytes = rdata.ipv6_address_.bytes();
+    return H::combine_contiguous(std::move(h), bytes, 16);
   }
 
  private:
@@ -408,8 +415,8 @@ class MdnsRecord {
   template <typename H>
   friend H AbslHashValue(H h, const MdnsRecord& record) {
     return H::combine(std::move(h), record.name_, record.dns_type_,
-                      record.dns_class_, record.record_type_, record.ttl_,
-                      record.rdata_);
+                      record.dns_class_, record.record_type_,
+                      record.ttl_.count(), record.rdata_);
   }
 
  private:
diff --git a/discovery/mdns/mdns_records_unittest.cc b/discovery/mdns/mdns_records_unittest.cc
index 0fab37de..6531697f 100644
--- a/discovery/mdns/mdns_records_unittest.cc
+++ b/discovery/mdns/mdns_records_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "discovery/mdns/mdns_records.h"
 
+#include "absl/hash/hash_testing.h"
 #include "discovery/mdns/mdns_reader.h"
 #include "discovery/mdns/mdns_writer.h"
 #include "discovery/mdns/testing/mdns_test_util.h"
@@ -102,6 +103,9 @@ TEST(MdnsDomainNameTest, Compare) {
 
   EXPECT_FALSE(fourth < fifth);
   EXPECT_FALSE(fifth < fourth);
+
+  EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(
+      {first, second, third, fourth, fifth}));
 }
 
 TEST(MdnsDomainNameTest, CopyAndMove) {
@@ -147,6 +151,9 @@ TEST(MdnsRawRecordRdataTest, Compare) {
 
   EXPECT_EQ(rdata1, rdata2);
   EXPECT_NE(rdata1, rdata3);
+
+  EXPECT_TRUE(
+      absl::VerifyTypeImplementsAbslHashCorrectly({rdata1, rdata2, rdata3}));
 }
 
 TEST(MdnsRawRecordRdataTest, CopyAndMove) {
@@ -185,6 +192,9 @@ TEST(MdnsSrvRecordRdataTest, Compare) {
   EXPECT_NE(rdata1, rdata4);
   EXPECT_NE(rdata1, rdata5);
   EXPECT_NE(rdata1, rdata6);
+
+  EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(
+      {rdata1, rdata2, rdata3, rdata4, rdata5, rdata6}));
 }
 
 TEST(MdnsSrvRecordRdataTest, CopyAndMove) {
@@ -208,6 +218,9 @@ TEST(MdnsARecordRdataTest, Compare) {
 
   EXPECT_EQ(rdata1, rdata2);
   EXPECT_NE(rdata1, rdata3);
+
+  EXPECT_TRUE(
+      absl::VerifyTypeImplementsAbslHashCorrectly({rdata1, rdata2, rdata3}));
 }
 
 TEST(MdnsARecordRdataTest, CopyAndMove) {
@@ -249,6 +262,9 @@ TEST(MdnsAAAARecordRdataTest, Compare) {
 
   EXPECT_EQ(rdata1, rdata2);
   EXPECT_NE(rdata1, rdata3);
+
+  EXPECT_TRUE(
+      absl::VerifyTypeImplementsAbslHashCorrectly({rdata1, rdata2, rdata3}));
 }
 
 TEST(MdnsAAAARecordRdataTest, CopyAndMove) {
@@ -275,6 +291,9 @@ TEST(MdnsPtrRecordRdataTest, Compare) {
 
   EXPECT_EQ(rdata1, rdata2);
   EXPECT_NE(rdata1, rdata3);
+
+  EXPECT_TRUE(
+      absl::VerifyTypeImplementsAbslHashCorrectly({rdata1, rdata2, rdata3}));
 }
 
 TEST(MdnsPtrRecordRdataTest, CopyAndMove) {
@@ -300,6 +319,9 @@ TEST(MdnsTxtRecordRdataTest, Compare) {
   EXPECT_EQ(rdata1, rdata2);
   EXPECT_NE(rdata1, rdata3);
   EXPECT_NE(rdata1, rdata4);
+
+  EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(
+      {rdata1, rdata2, rdata3, rdata4}));
 }
 
 TEST(MdnsTxtRecordRdataTest, CopyAndMove) {
@@ -428,6 +450,9 @@ TEST(MdnsNsecRecordRdataTest, Compare) {
   EXPECT_NE(rdata1, rdata3);
   EXPECT_NE(rdata1, rdata4);
   EXPECT_NE(rdata3, rdata4);
+
+  EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(
+      {rdata1, rdata2, rdata3, rdata4}));
 }
 
 TEST(MdnsNsecRecordRdataTest, CopyAndMove) {
@@ -489,6 +514,9 @@ TEST(MdnsRecordTest, Compare) {
   EXPECT_NE(record1, record5);
   EXPECT_NE(record1, record6);
   EXPECT_NE(record1, record7);
+
+  EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(
+      {record1, record2, record3, record4, record5, record6, record7}));
 }
 
 TEST(MdnsRecordTest, CopyAndMove) {
@@ -531,6 +559,9 @@ TEST(MdnsQuestionTest, Compare) {
   EXPECT_NE(question1, question3);
   EXPECT_NE(question1, question4);
   EXPECT_NE(question1, question5);
+
+  EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(
+      {question1, question2, question3, question4, question5}));
 }
 
 TEST(MdnsQuestionTest, CopyAndMove) {
@@ -656,6 +687,10 @@ TEST(MdnsMessageTest, Compare) {
   EXPECT_NE(message1, message6);
   EXPECT_NE(message1, message7);
   EXPECT_NE(message1, message8);
+
+  EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly(
+      {message1, message2, message3, message4, message5, message6, message7,
+       message8}));
 }
 
 TEST(MdnsMessageTest, CopyAndMove) {