Fix Bazel presubmit test (#118)

The Bazel presubmit tests are meant to pass, but currently point to a
test that intentionally does not pass.
- Move existing test that fails on purpose from `examples/bzlmod` to
`examples/unused`
- Add new test based on `examples/unused` but without the lint error in
`examples/bzlmod`.

Author: jchadwick-buf

MODULE.bazel.lock

@@ -40,7 +40,6 @@ proto_library(
     name = "root_proto",
     srcs = [
         "file.proto",
-        "unused.proto",
     ],
     visibility = ["//visibility:public"],
     deps = ["@buf_deps//validate:validate_proto"],

examples/bzlmod/BUILD.bazel

@@ -13,6 +13,3 @@
 // limitations under the License.
 
 syntax = "proto3";
-
-import "unused.proto";
-import "validate/validate.proto";

examples/bzlmod/MODULE.bazel.lock

@@ -0,0 +1 @@
+common --enable_bzlmod --experimental_proto_descriptor_sets_include_source_info

examples/bzlmod/file.proto

@@ -0,0 +1,57 @@
+# Copyright 2021-2025 Buf Technologies, Inc.
+#
+# 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.
+
+load("@rules_buf//buf:defs.bzl", "buf_format", "buf_lint_test")
+load("@rules_proto//proto:defs.bzl", "proto_library")
+load("@gazelle//:def.bzl", "gazelle", "gazelle_binary")
+
+exports_files(
+    ["buf.yaml"],
+    visibility = ["//visibility:public"],
+)
+
+gazelle(
+    name = "gazelle",
+    gazelle = ":gazelle-buf",
+)
+
+gazelle_binary(
+    name = "gazelle-buf",
+    languages = [
+        "@gazelle//language/proto",  # Built-in rule from gazelle for Protos.
+        # Any languages that depend on Gazelle's proto plugin must come after it.
+        "@rules_buf//gazelle/buf:buf",  # Loads the Buf extension
+    ],
+    visibility = ["//visibility:public"],
+)
+
+proto_library(
+    name = "root_proto",
+    srcs = [
+        "file.proto",
+        "unused.proto",
+    ],
+    visibility = ["//visibility:public"],
+    deps = ["@buf_deps//validate:validate_proto"],
+)
+
+buf_lint_test(
+    name = "root_proto_lint",
+    config = "//:buf.yaml",
+    targets = [":root_proto"],
+)
+
+buf_format(
+    name = "buf_format",
+)

examples/unused/.bazelrc

@@ -0,0 +1,41 @@
+# Copyright 2021-2025 Buf Technologies, Inc.
+#
+# 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.
+
+"Bazel dependencies"
+
+bazel_dep(name = "rules_buf", version = "0.0.0", dev_dependency = True)
+bazel_dep(name = "gazelle", version = "0.34.0", dev_dependency = True)
+
+bazel_dep(name = "protobuf", version = "29.0", repo_name = "com_google_protobuf")
+bazel_dep(name = "rules_proto", version = "7.0.2")
+
+local_path_override(
+    module_name = "rules_buf",
+    path = "../..",
+)
+
+buf = use_extension("@rules_buf//buf:extensions.bzl", "buf")
+
+# Override the default version of buf
+buf.toolchains(version = "v1.47.2")
+
+# See https://buf.build/docs/build-systems/bazel#buf-dependencies
+buf.dependency(module = "buf.build/envoyproxy/protoc-gen-validate:eac44469a7af47e7839a7f1f3d7ac004")
+buf.dependency(module = "buf.build/acme/petapis:7abdb7802c8f4737a1a23a35ca8266ef")
+
+# Allow references to labels under @buf_deps
+use_repo(buf, "buf_deps")
+
+# Allow people to use `bazel run @rules_buf_toolchains//:buf -- --version`
+use_repo(buf, "rules_buf_toolchains")