Gencode runtime tests pointing to latest v27.x-compat-upgrade commit with proposed compatibility shims

WORKSPACE

@@ -198,3 +198,14 @@ crates_repository(
 
 load("@crate_index//:defs.bzl", "crate_repositories")
 crate_repositories()
+
+# For testing previous major version against latest runtime.
+http_archive(
+    name = "com_google_protobuf_head",
+    strip_prefix = "protobuf-35aa857de8e99174c9a4c23e9b9e4cb64785f5f0",
+    url = "https://github.com/protocolbuffers/protobuf/archive/35aa857de8e99174c9a4c23e9b9e4cb64785f5f0.zip",
+)
+
+# Load protobuf_deps from head.
+load("@com_google_protobuf_head//:protobuf_deps.bzl", protobuf_head_deps="protobuf_deps")
+protobuf_head_deps()

java/core/BUILD.bazel

@@ -383,6 +383,59 @@ junit_tests(
     ],
 )
 
+junit_tests(
+    name = "head_generated_message_test",
+    size = "small",
+    srcs = [
+        "src/test/java/com/google/protobuf/GeneratedMessageTest.java",
+    ],
+    data = ["//src/google/protobuf:testdata"],
+    deps = [
+        "@com_google_protobuf_head//java/core:core",
+        ":generic_test_protos_java_proto",
+        ":java_test_protos_java_proto",
+        ":lite_test_protos_java_proto",
+        ":test_util",
+        "@maven//:com_google_guava_guava",
+        "@maven//:com_google_truth_truth",
+        "@maven//:junit_junit",
+        "@maven//:org_mockito_mockito_core",
+    ],
+)
+
+junit_tests(
+    name = "head_core_tests",
+    size = "small",
+    srcs = glob(
+        ["src/test/java/**/*.java"],
+        exclude = [
+            # Exclusions from :core_tests
+            "src/test/java/com/google/protobuf/DecodeUtf8Test.java",
+            "src/test/java/com/google/protobuf/IsValidUtf8Test.java",
+            "src/test/java/com/google/protobuf/TestUtil.java",
+            "src/test/java/com/google/protobuf/TestUtilLite.java",
+            # Already failing on :core_tests
+            # "src/test/java/com/google/protobuf/AbstractProto2LiteSchemaTest.java",
+            # "src/test/java/com/google/protobuf/AbstractProto2SchemaTest.java",
+            # "src/test/java/com/google/protobuf/AbstractProto3LiteSchemaTest.java",
+            # "src/test/java/com/google/protobuf/AbstractProto3SchemaTest.java",
+            # "src/test/java/com/google/protobuf/AbstractSchemaTest.java",
+        ],
+    ),
+    data = ["//src/google/protobuf:testdata"],
+    deps = [
+        "@com_google_protobuf_head//java/core:core",
+        ":generic_test_protos_java_proto",
+        ":java_test_protos_java_proto",
+        ":lite_test_protos_java_proto",
+        ":test_util",
+        "@maven//:com_google_guava_guava",
+        "@maven//:com_google_truth_truth",
+        "@maven//:junit_junit",
+        "@maven//:org_mockito_mockito_core",
+    ],
+)
+
 # The UTF-8 validation tests are much slower than the other tests, so they get
 # their own test target with a longer timeout.
 junit_tests(

java/internal/testing.bzl

@@ -46,7 +46,7 @@ def junit_tests(name, srcs, data = [], deps = [], package_name = "com.google.pro
     test_names = []
     prefix = name.replace("-", "_") + "TestSuite"
     for src in srcs:
-        test_name = src.rsplit("/", 1)[1].split(".")[0]
+        test_name = name + "_" + src.rsplit("/", 1)[1].split(".")[0]
         if not test_name.endswith("Test") or test_name.startswith("Abstract"):
             continue
         if test_prefix: