1# Copyright 2019 The Bazel 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 15"""A test verifying other targets build as part of a `bazel test`""" 16 17load("//lib:new_sets.bzl", "sets") 18 19def _empty_test_impl(ctx): 20 extension = ".bat" if ctx.attr.is_windows else ".sh" 21 content = "exit 0" if ctx.attr.is_windows else "#!/usr/bin/env bash\nexit 0" 22 executable = ctx.actions.declare_file(ctx.label.name + extension) 23 ctx.actions.write( 24 output = executable, 25 is_executable = True, 26 content = content, 27 ) 28 29 return [DefaultInfo( 30 files = depset([executable]), 31 executable = executable, 32 runfiles = ctx.runfiles(files = ctx.files.data), 33 )] 34 35_empty_test = rule( 36 implementation = _empty_test_impl, 37 attrs = { 38 "data": attr.label_list(allow_files = True), 39 "is_windows": attr.bool(mandatory = True), 40 }, 41 test = True, 42) 43 44_GENRULE_ATTRS = [ 45 "compatible_with", 46 "exec_compatible_with", 47 "restricted_to", 48 "tags", 49 "target_compatible_with", 50] 51 52def build_test(name, targets, **kwargs): 53 """Test rule checking that other targets build. 54 55 This works not by an instance of this test failing, but instead by 56 the targets it depends on failing to build, and hence failing 57 the attempt to run this test. 58 59 Typical usage: 60 61 ``` 62 load("@bazel_skylib//rules:build_test.bzl", "build_test") 63 build_test( 64 name = "my_build_test", 65 targets = [ 66 "//some/package:rule", 67 ], 68 ) 69 ``` 70 71 Args: 72 name: The name of the test rule. 73 targets: A list of targets to ensure build. 74 **kwargs: The [common attributes for tests](https://bazel.build/reference/be/common-definitions#common-attributes-tests). 75 """ 76 if len(targets) == 0: 77 fail("targets must be non-empty", "targets") 78 if kwargs.get("data", None): 79 fail("data is not supported on a build_test()", "data") 80 81 # Remove any duplicate test targets. 82 targets = sets.to_list(sets.make(targets)) 83 84 # Use a genrule to ensure the targets are built (works because it forces 85 # the outputs of the other rules on as data for the genrule) 86 87 # Split into batches to hopefully avoid things becoming so large they are 88 # too much for a remote execution set up. 89 batch_size = max(1, len(targets) // 100) 90 91 # Pull a few args over from the test to the genrule. 92 genrule_args = {k: kwargs.get(k) for k in _GENRULE_ATTRS if k in kwargs} 93 94 # Only the test target should be used to determine whether or not the deps 95 # are built. Tagging the genrule targets as manual accomplishes this by 96 # preventing them from being picked up by recursive build patterns (`//...`). 97 genrule_tags = genrule_args.pop("tags", []) 98 if "manual" not in genrule_tags: 99 genrule_tags = genrule_tags + ["manual"] 100 101 # Pass an output from the genrules as data to a shell test to bundle 102 # it all up in a test. 103 test_data = [] 104 105 for idx, batch in enumerate([targets[i:i + batch_size] for i in range(0, len(targets), batch_size)]): 106 full_name = "{name}_{idx}__deps".format(name = name, idx = idx) 107 test_data.append(full_name) 108 native.genrule( 109 name = full_name, 110 srcs = batch, 111 outs = [full_name + ".out"], 112 testonly = 1, 113 visibility = ["//visibility:private"], 114 cmd = "touch $@", 115 cmd_bat = "type nul > $@", 116 tags = genrule_tags, 117 **genrule_args 118 ) 119 120 _empty_test( 121 name = name, 122 data = test_data, 123 size = kwargs.pop("size", "small"), # Default to small for test size 124 is_windows = select({ 125 "@bazel_tools//src/conditions:host_windows": True, 126 "//conditions:default": False, 127 }), 128 **kwargs 129 ) 130