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Diffstat (limited to 'kotlin/common/testing/unittest_suites.bzl')
| -rw-r--r-- | kotlin/common/testing/unittest_suites.bzl | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/kotlin/common/testing/unittest_suites.bzl b/kotlin/common/testing/unittest_suites.bzl new file mode 100644 index 0000000..b1895bf --- /dev/null +++ b/kotlin/common/testing/unittest_suites.bzl @@ -0,0 +1,205 @@ +# Copyright 2022 Google LLC. All rights reserved. +# +# 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 +# +# http://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. + +"""A framework for writing tests of Starlark code with minimal overhead. + +Test cases are written as Starlark functions that will eventually be executed as +individual test targets. Two types of tests are supported: those including their +own assertions, and those expected to call 'fail()'. + +Basic usage looks like: +``` +# unittests.bzl +load("//kotlin/common/testing:unittest_suites.bzl", "kt_unittest_suites") +load("@bazel_skylib//lib:unittest.bzl", "asserts") + +unittests = kt_unittest_suite.create() # Create a new suite in this file. + +def _some_test_case(ctx, env): + # Test logic here + asserts.true(env, 1 == 1) + return [] # Return any declared files + +unittests.expect_finish(_some_test_case) # Include the test case in the suite + +def _some_fail_case(ctx): + # No assertions are allowed in fail cases + _some_logic_that_should_call_fail(ctx) + +unittests.expect_fail(_some_fail_case, "fail message substring") # Expect this case to call fail + +# Generate a pair of rules that will be used for test targets +_test, _fail = unittests.close() # @unused +``` + +``` +// BUILD +load(":unittests.bzl", "unittests") + +# Render each test case as a target in this package +unittests.render( + name = "unittests" +) +``` +""" + +load("//:visibility.bzl", "RULES_KOTLIN") +load("@bazel_skylib//lib:unittest.bzl", "unittest") +load(":testing_rules.bzl", "kt_testing_rules") + +visibility(RULES_KOTLIN) + +def _create(): + """Create a new test suite. + + Returns: + [kt_unittest_suite] An object representing the suite under construction + """ + + test_cases = dict() + rule_holder = [] # Use a list rather than separate vars becase captured vars are final + + def expect_fail(test_case, msg_contains): + """Add a test case to the suite which is expected to call fail. + + Args: + test_case: [function(ctx)] + msg_contains: [string] A substring expected in the failure message + """ + + if rule_holder: + fail("Test suite is closed") + + test_case_name = _fn_name(test_case) + if not test_case_name.startswith("_"): + fail("Test cases must be private '%s'" % test_case_name) + if test_case_name in test_cases: + fail("Existing test case named '%s'" % test_case_name) + + test_cases[test_case_name] = struct( + impl = test_case, + msg_contains = msg_contains, + ) + + def expect_finish(test_case): + """Add a test case to the suite. + + Args: + test_case: [function(ctx,unittest.env):None|list[File]] + """ + + expect_fail(test_case, None) + + def close(): + """Close the suite from expect_finishing new tests. + + The return value must be assigned to '_test, _fail' with an '# @unused' suppression. + + Returns: + [(rule, rule)] + """ + + if rule_holder: + fail("Test suite is closed") + + def test_impl(ctx): + env = unittest.begin(ctx) + + output_files = test_cases[ctx.attr.case_name].impl(ctx, env) or [] + if output_files: + ctx.actions.run_shell( + outputs = output_files, + command = "exit 1", + ) + + return unittest.end(env) + [OutputGroupInfo(_file_sink = depset(output_files))] + + test_rule = unittest.make( + impl = test_impl, + attrs = dict(case_name = attr.string()), + ) + rule_holder.append(test_rule) + + def fail_impl(ctx): + test_cases[ctx.attr.case_name].impl(ctx) + return [] + + fail_rule = rule( + implementation = fail_impl, + attrs = dict(case_name = attr.string()), + ) + rule_holder.append(fail_rule) + + # Rules must be assigned to top-level Starlark vars before being called + return test_rule, fail_rule + + def render(name, tags = [], **kwargs): + """Render the test suite into targets. + + Args: + name: [string] + tags: [list[string]] + **kwargs: Generic rule kwargs + """ + + if not rule_holder: + fail("Test suite is not closed") + test_rule = rule_holder[0] + fail_rule = rule_holder[1] + + test_targets = [] + for test_case_name, test_case_data in test_cases.items(): + target_name = test_case_name.removeprefix("_") + "_test" + test_targets.append(target_name) + + if test_case_data.msg_contains == None: + test_rule( + name = target_name, + tags = tags, + case_name = test_case_name, + **kwargs + ) + else: + fail_rule( + name = test_case_name, + tags = tags + kt_testing_rules.ONLY_FOR_ANALYSIS_TAGS, + case_name = test_case_name, + **kwargs + ) + kt_testing_rules.assert_failure_test( + name = target_name, + target_under_test = test_case_name, + msg_contains = test_case_data.msg_contains, + ) + + native.test_suite( + name = name, + tests = test_targets, + **kwargs + ) + + return struct( + expect_finish = expect_finish, + expect_fail = expect_fail, + close = close, + render = render, + ) + +def _fn_name(rule_or_fn): + parts = str(rule_or_fn).removeprefix("<").removesuffix(">").split(" ") + return parts[0] if (len(parts) == 1) else parts[1] + +kt_unittest_suites = struct( + create = _create, +) |