daml/bazel_tools/client_server/client_server_test.bzl

# Copyright (c) 2022 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
# SPDX-License-Identifier: Apache-2.0

load("//bazel_tools/sh:sh.bzl", "sh_inline_test")

def _escape_args(args):
    return " ".join([
        a.replace("'", "'\\''")
        for a in args
    ])

def client_server_test(
        name,
        runner = "//bazel_tools/client_server/runner_with_port_file",
        runner_args = [],
        runner_files = [],
        runner_files_prefix = "",
        client = None,
        client_args = [],
        client_files = [],
        server = None,
        server_args = [],
        server_files = [],
        server_files_prefix = "",
        data = [],
        **kwargs):
    """Create a client-server test.

    The rule takes a client and server executables and their
    arguments as parameters. The server port is passed via a
    temporary file, which is passed to the server executable via the
    "--port-file" parameter. This file is parsed and the port number
    is passed to the client application via the "--target-port" argument.

    The server process is killed after the client process exits.

    The client and server executables can be any Bazel target that
    is executable, e.g. scala_binary, sh_binary, etc.

    The client and server files must be valid arguments to rlocation, as
    can be obtained using $(rootpath ...) or $(rootpaths ...). (See
    https://docs.bazel.build/versions/master/be/make-variables.html#predefined_label_variables.)
    Once expanded using rlocation, those are simply appended to client
    and server arguments, respectively.

    Example:
      ```bzl
      client_server_test(
        name = "my_test",
        runner_args = [],
        client = ":my_client",
        client_args = ["--extra-argument"],
        client_files = ["$(rootpath :target-for-client)"]
        server = ":my_server",
        server_args = ["--fast"],
        server_files = ["$(rootpath :target-for-client)"]
      )
      ```
    """
    sh_inline_test(
        name = name,
        # Deduplicate in case any of runner, client, server are identical.
        data = depset([runner, client, server]).to_list() + data,
        cmd = """\
runner=$$(canonicalize_rlocation $$(get_exe $(rootpaths {runner})))
runner_args="{runner_args}"
for file in {runner_files}; do
    runner_args+=" {runner_files_prefix}$$(canonicalize_rlocation $$file)"
done
client=$$(canonicalize_rlocation $$(get_exe $(rootpaths {client})))
server=$$(canonicalize_rlocation $$(get_exe $(rootpaths {server})))
server_args="{server_args}"
for file in {server_files}; do
    server_args+=" {server_files_prefix}$$(canonicalize_rlocation $$file)"
done

client_args="$$@"
if [ -z "$$client_args" ]; then
    client_args="{client_args}"
    for file in {client_files}; do
        client_args+=" $$(canonicalize_rlocation $$file)"
    done
fi

$$runner $$client "$$client_args" $$server "$$server_args" "$$runner_args"
""".format(
            runner = runner,
            runner_args = _escape_args(runner_args),
            runner_files = _escape_args(runner_files),
            runner_files_prefix = runner_files_prefix,
            client = client,
            client_args = _escape_args(client_args),
            client_files = _escape_args(client_files),
            server = server,
            server_args = _escape_args(server_args),
            server_files = _escape_args(server_files),
            server_files_prefix = server_files_prefix,
        ),
        **kwargs
    )