1# Copyright 2017 The Bazel Go Rules Authors. All rights reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14 15def _impl(ctx): 16 exe = ctx.outputs.out 17 ctx.actions.write( 18 output = exe, 19 # The file must not be empty because running an empty .bat file as a 20 # subprocess fails on Windows, so we write one space to it. 21 content = " ", 22 is_executable = True, 23 ) 24 return [DefaultInfo(files = depset([exe]), executable = exe)] 25 26_single_output_test = rule( 27 implementation = _impl, 28 attrs = { 29 "dep": attr.label(allow_single_file = True), 30 "out": attr.output(), 31 }, 32 test = True, 33) 34 35def single_output_test(name, dep, **kwargs): 36 """Checks that a dependency produces a single output file. 37 38 This test works by setting `allow_single_file = True` on the `dep` attribute. 39 If `dep` provides zero or multiple files in its `files` provider, Bazel will 40 fail to build this rule during analysis. The actual test does nothing. 41 42 Args: 43 name: The name of the test rule. 44 dep: a label for the rule to check. 45 **kwargs: The <a href="https://docs.bazel.build/versions/master/be/common-definitions.html#common-attributes-tests">common attributes for tests</a>. 46 """ 47 48 _single_output_test( 49 name = name, 50 dep = dep, 51 # On Windows we need the ".bat" extension. 52 # On other platforms the extension doesn't matter. 53 # Therefore we can use ".bat" on every platform. 54 out = name + ".bat", 55 **kwargs 56 ) 57