def _overwrite_golden_impl(ctx):

test_class = ctx.attr.test_class

inputs = ctx.files.srcs

goldens_output_zip = ctx.outputs.goldens_output_zip

test_runner = ctx.executable.test_runner

# Generate the goldens from tests.

generate_goldens_script = """

mkdir local_tmp

TEST_OUTPUT_HOME="$(pwd)/local_tmp" {test_runner_path} $@

cd local_tmp

# Zip all files under local_tmp with all nested parent folders except for local_tmp itself.

# Zip files because there are cases that one Junit test can produce multiple goldens.

zip -r ../{goldens_output_zip} .

""".format(

test_runner_path = test_runner.path,

goldens_output_zip = goldens_output_zip.path,

)

ctx.actions.run_shell(

inputs = inputs,

outputs = [goldens_output_zip],

arguments = [test_class],

tools = [test_runner],

command = generate_goldens_script,

)

# Overwrite the goldens.

golden_update_script_content = """

#!/bin/bash

cd ${{BUILD_WORKSPACE_DIRECTORY}}

unzip -ao {goldens_output_zip} -d src/test/java

""".format(

goldens_output_zip = goldens_output_zip.path,

)

ctx.actions.write(

output = ctx.outputs.golden_update_script,

content = golden_update_script_content,

is_executable = True,

)

return [DefaultInfo(executable = ctx.outputs.golden_update_script)]

overwrite_golden = rule(

attrs = {

"test_class": attr.string(mandatory = True),

"srcs": attr.label_list(

allow_files = True,

mandatory = True,

),

"test_runner": attr.label(

mandatory = True,

executable = True,

cfg = "host",

),

},

outputs = {

"goldens_output_zip": "%{name}.zip",

"golden_update_script": "%{name}.sh",

},

executable = True,

implementation = _overwrite_golden_impl,

)

def golden_update(

name,

srcs,

test_class,

data = [],

deps = []):

golden_junit_runner_name = "%s_junit_runner" % name

native.java_binary(

name = golden_junit_runner_name,

srcs = srcs,

data = data,

main_class = "com.google.api.generator.test.framework.SingleJUnitTestRunner",

deps = ["//src/test/java/com/google/api/generator/test/framework:junit_runner"] + deps,

)

overwrite_golden(

name = name,

test_class = test_class,

test_runner = ":%s" % golden_junit_runner_name,

srcs = srcs + data,

)