test(showcase): add script to test against local showcase repo

This is useful during Showcase development.

showcase/README.md

@@ -5,23 +5,28 @@ gapic-generator-go, as well as the script used to setup and execute them.
 
 ## How the tests work
 
+### Testing the released Showcase GAPIC client
 The tests can be run out-of-the-box in the normal `go test` fashion, so long as
 there is a `gapic-showcase` server already running locally. This does not test
 the Showcase client generated with the locally installed generator - it would
-use the released version of the GAPIC. Running `make test` (from the repository
-root) will execute the tests against the locally installed generator.
+use the released version of the GAPIC.
 
-To test the local generator, use the `showcase.bash` script. It does the
-following:
+### Testing client locally generated from published Showcase repo
+Running `make test` (from the repository root) will execute the tests against
+the locally installed generator. It installs the generator locally and then
+calls the `showcase.bash` script to test the local generator. The script does
+the following:
 
 1. Downloads the Showcase artifacts associated with the targeted version.
 These are the compiled proto descriptor set, the retry configuration, and a
 pre-compiled server binary.
 
 1. Using protoc and the retrieved artifacts as input, the Go protobuf/gRPC
 bindings, and the Go GAPIC are generated, the latter with the **locally
-installed** gapic-generator-go. Make sure to `make install` (from the repository
-root) so that any new changes are utilized during generation.
+installed** gapic-generator-go. If invoking the script directly, make sure to
+`make install` (from the repository root) so that any new changes are utilized
+during generation; if invoking the script via `make test`, this will
+automatically happen.
 
 1. The submodule's `go.mod` is temporarily edited to replace the remote
 dependency on `github.com/googleapis/gapic-showcase` with the locally generated
@@ -33,6 +38,12 @@ artifacts.
 
 1. The server process is stopped.
 
+### Testing client locally generated from local Showcase repo
+During development, it may sometimes be necessary to run the Go Showcase tests
+against a local version of Showcase with pending changes that are not yet in the
+[googleapis/gapic-showcase](https://github.com/googleapis/gapic-showcase/releases/tag/v0.28.1)
+repository. To do that, refer to [showcase-local.sh](./showcase-local.sh).
+
 ### Adding tests
 
 Adding tests for an existing service is as easy as adding a new Go test to the

showcase/showcase-local.sh

@@ -0,0 +1,76 @@
+# Copyright 2023 Google LLC
+#
+# 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
+#
+#     https://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.
+
+# To run the gapic-generator-go Showcase tests using a local version of Showcase
+# (eg in development), set the following variables before calling the
+# test-with-local-showcase function below.
+
+GO_GENERATOR="$(pwd)/.."
+API_COMMON_PROTOS="" # path to local version of api-common-protos
+LOCAL_SHOWCASE_REPO="" # path to local version of gapic-showcase
+
+test-with-local-showcase(){
+
+  [[ -n "${GO_GENERATOR}" ]] || { echo '${GO_GENERATOR} must be set' ; return 1 ; }
+  [[ -n "${API_COMMON_PROTOS}" ]] || { echo '${API_COMMON_PROTOS} must be set' ; return 1 ; }
+  [[ -n "${LOCAL_SHOWCASE_REPO}" ]] || { echo '${LOCAL_SHOWCASE_REPO} must be set' ; return 1 ; }
+
+  GO_GENERATOR="$(realpath ${GO_GENERATOR})"
+  API_COMMON_PROTOS="$(realpath ${API_COMMON_PROTOS})"
+  LOCAL_SHOWCASE_REPO="$(realpath ${LOCAL_SHOWCASE_REPO})"
+  SHOWCASE_SCHEMA="${LOCAL_SHOWCASE_REPO}/schema/google/showcase/v1beta1"
+
+
+  cat <<EOF
+Running with:
+  GO_GENERATOR:        ${GO_GENERATOR}
+  API_COMMON_PROTOS:   ${API_COMMON_PROTOS}
+  LOCAL_SHOWCASE_REPO: ${LOCAL_SHOWCASE_REPO}
+EOF
+
+
+  pushd "${GO_GENERATOR}" >& /dev/null
+  go install ./cmd/protoc-gen-go_gapic
+
+  cd showcase
+
+  GAPIC_OUT_DIR="./gen"
+  rm -rf $GAPIC_OUT_DIR
+  mkdir -p $GAPIC_OUT_DIR
+  protoc --experimental_allow_proto3_optional -I $API_COMMON_PROTOS  \
+    --go_gapic_out $GAPIC_OUT_DIR \
+    --go_gapic_opt 'transport=rest+grpc' \
+    --go_gapic_opt 'rest-numeric-enums' \
+    --go_gapic_opt='go-gapic-package=github.com/googleapis/gapic-showcase/client;client' \
+    --go_gapic_opt=grpc-service-config=${SHOWCASE_SCHEMA}/showcase_grpc_service_config.json \
+    --go_gapic_opt=api-service-config=${SHOWCASE_SCHEMA}/showcase_v1beta1.yaml \
+    $PLUGIN --proto_path=$SHOWCASE_SCHEMA $SHOWCASE_SCHEMA/*.proto
+
+  go mod edit -replace=github.com/googleapis/gapic-showcase=./gen/github.com/googleapis/gapic-showcase
+
+  pushd ./gen/github.com/googleapis/gapic-showcase  >& /dev/null
+  go mod init gapic-showcase
+  mkdir server
+  ln -s ${LOCAL_SHOWCASE_REPO}/server/genproto server/
+  popd  >& /dev/null
+
+  # ensure your Showcase server is running
+
+  cp ${LOCAL_SHOWCASE_REPO}/server/services/compliance_suite.json .
+  go test -mod=mod -count=1 ./...
+
+  popd  >& /dev/null
+}
+
+test-with-local-showcase