serve service: Respond also with digest in serve repository tree RPCs

...besides the simple Git hash, if syncing was done. This way one
can know what digest to ask for from the remote. The serve client
also needs to now know what hash function the remote expects.

The serve service proto file is updated accordingly.

2 files changed, 36 insertions, 9 deletions

diff --git a/test/buildtool/serve_api/TARGETS b/test/buildtool/serve_api/TARGETS
index 656a3ae7..69455203 100644
--- a/test/buildtool/serve_api/TARGETS
+++ b/test/buildtool/serve_api/TARGETS
@@ -6,19 +6,28 @@
   , "private-deps":
     [ ["@", "catch2", "", "catch2"]
     , ["@", "src", "src/buildtool/auth", "auth"]
+    , ["@", "src", "src/buildtool/common", "protocol_traits"]
     , ["@", "src", "src/buildtool/common/remote", "retry_config"]
+    , ["@", "src", "src/buildtool/crypto", "hash_function"]
     , ["@", "src", "src/buildtool/execution_api/remote", "config"]
     , ["@", "src", "src/buildtool/execution_api/remote", "context"]
     , ["@", "src", "src/buildtool/serve_api/remote", "config"]
     , ["@", "src", "src/buildtool/serve_api/remote", "source_tree_client"]
     , ["utils", "catch-main-serve"]
+    , ["utils", "test_hash_function_type"]
     , ["utils", "test_serve_config"]
     ]
   , "stage": ["test", "buildtool", "serve_api"]
   }
 , "TESTS":
   { "type": ["@", "rules", "test", "suite"]
+  , "arguments_config": ["TEST_COMPATIBLE_REMOTE"]
   , "stage": ["serve_api"]
-  , "deps": ["source_tree_client"]
+  , "deps":
+    { "type": "if"
+    , "cond": {"type": "var", "name": "TEST_COMPATIBLE_REMOTE"}
+    , "then": []
+    , "else": ["source_tree_client"]
+    }
   }
 }
diff --git a/test/buildtool/serve_api/source_tree_client.test.cpp b/test/buildtool/serve_api/source_tree_client.test.cpp
index 7c9634df..8ada1317 100644
--- a/test/buildtool/serve_api/source_tree_client.test.cpp
+++ b/test/buildtool/serve_api/source_tree_client.test.cpp
@@ -19,10 +19,13 @@
 
 #include "catch2/catch_test_macros.hpp"
 #include "src/buildtool/auth/authentication.hpp"
+#include "src/buildtool/common/protocol_traits.hpp"
 #include "src/buildtool/common/remote/retry_config.hpp"
+#include "src/buildtool/crypto/hash_function.hpp"
 #include "src/buildtool/execution_api/remote/config.hpp"
 #include "src/buildtool/execution_api/remote/context.hpp"
 #include "src/buildtool/serve_api/remote/config.hpp"
+#include "test/utils/hermeticity/test_hash_function_type.hpp"
 #include "test/utils/serve_service/test_serve_config.hpp"
 
 auto const kRootCommit =
@@ -36,9 +39,11 @@ auto const kRootSymId = std::string{"18770dacfe14c15d88450c21c16668e13ab0e7f9"};
 auto const kBazSymId = std::string{"1868f82682c290f0b1db3cacd092727eef1fa57f"};
 
 TEST_CASE("Serve service client: tree-of-commit request", "[serve_api]") {
-    auto config = TestServeConfig::ReadFromEnvironment();
+    auto const config = TestServeConfig::ReadFromEnvironment();
     REQUIRE(config);
     REQUIRE(config->remote_address);
+    auto const hash_function =
+        HashFunction{TestHashType::ReadFromEnvironment()};
 
     // Create TLC client
     Auth auth{};
@@ -48,26 +53,39 @@ TEST_CASE("Serve service client: tree-of-commit request", "[serve_api]") {
                                        .retry_config = &retry_config,
                                        .exec_config = &exec_config};
 
-    SourceTreeClient st_client(*config->remote_address, &remote_context);
+    SourceTreeClient st_client(
+        *config->remote_address, &hash_function, &remote_context);
 
     SECTION("Commit in bare checkout") {
         auto root_id = st_client.ServeCommitTree(kRootCommit, ".", false);
         REQUIRE(root_id);
-        CHECK(*root_id == kRootId);
+        CHECK_FALSE(root_id->digest);  // digest is not provided if not syncing
+        if (ProtocolTraits::IsNative(hash_function.GetType())) {
+            CHECK(root_id->tree == kRootId);
+        }
 
         auto baz_id = st_client.ServeCommitTree(kRootCommit, "baz", false);
         REQUIRE(baz_id);
-        CHECK(*baz_id == kBazId);
+        CHECK_FALSE(baz_id->digest);  // digest is not provided if not syncing
+        if (ProtocolTraits::IsNative(hash_function.GetType())) {
+            CHECK(baz_id->tree == kBazId);
+        }
     }
 
     SECTION("Commit in non-bare checkout") {
         auto root_id = st_client.ServeCommitTree(kRootSymCommit, ".", false);
         REQUIRE(root_id);
-        CHECK(*root_id == kRootSymId);
+        CHECK_FALSE(root_id->digest);  // digest is not provided if not syncing
+        if (ProtocolTraits::IsNative(hash_function.GetType())) {
+            CHECK(root_id->tree == kRootSymId);
+        }
 
         auto baz_id = st_client.ServeCommitTree(kRootSymCommit, "baz", false);
         REQUIRE(baz_id);
-        CHECK(*baz_id == kBazSymId);
+        CHECK_FALSE(baz_id->digest);  // digest is not provided if not syncing
+        if (ProtocolTraits::IsNative(hash_function.GetType())) {
+            CHECK(baz_id->tree == kBazSymId);
+        }
     }
 
     SECTION("Subdir not found") {
@@ -81,7 +99,7 @@ TEST_CASE("Serve service client: tree-of-commit request", "[serve_api]") {
         auto root_id = st_client.ServeCommitTree(
             "0123456789abcdef0123456789abcdef01234567", ".", false);
         REQUIRE_FALSE(root_id);
-        CHECK_FALSE(root_id.error() ==
-                    GitLookupError::Fatal);  // non-fatal failure
+        CHECK(root_id.error() ==
+              GitLookupError::NotFound);  // non-fatal failure
     }
 }