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Diffstat (limited to 'src/buildstream/testing/_cachekeys.py')
-rw-r--r-- | src/buildstream/testing/_cachekeys.py | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/buildstream/testing/_cachekeys.py b/src/buildstream/testing/_cachekeys.py new file mode 100644 index 000000000..a7ea5ad7e --- /dev/null +++ b/src/buildstream/testing/_cachekeys.py @@ -0,0 +1,148 @@ +# +# Copyright (C) 2020 Bloomberg Finance LP +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2 of the License, or (at your option) any later version. +# +# This library is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library. If not, see <http://www.gnu.org/licenses/>. +# + +import os +from collections import OrderedDict + +from .runcli import Cli + + +def check_cache_key_stability(project_path: os.PathLike, cli: Cli) -> None: + """ + Check that the cache key of various elements has not changed. + + This ensures that elements do not break cache keys unexpectedly. + + The format of the project is expected to be: + + .. code-block:: + + ./ + ./project.conf + ./elem1.bst + ./elem1.expected + ./elem2.bst + ./elem2.expected + # Or in sub-directories + ./mydir/elem3.bst + ./mydir/elem3.expected + + The ``.expected`` file should contain the expected cache key. + + In order to automatically created the ``.expected`` files, or updated them, + you can run ``python3 -m buildstream.testing._update_cachekeys`` in the + project's directory. + + :param project_path: Path to a project + :param cli: a `cli` object as provided by the fixture :func:`buildstream.testing.runcli.cli` + """ + result = cli.run( + project=project_path, silent=True, args=["show", "--format", "%{name}::%{full-key}", "target.bst"] + ) + result.assert_success() + _assert_cache_keys(project_path, result.output) + + +############################### +## Internal Helper functions ## +############################### +# Those functions are for internal use only and are not part of the public API + + +def _element_filename(project_dir, element_name, alt_suffix=None): + # Get whole filename in the temp project with + # the option of changing the .bst suffix to something else + # + if alt_suffix: + + # Just in case... + assert element_name.endswith(".bst") + + # Chop off the 'bst' in '.bst' and add the new suffix + element_name = element_name[:-3] + element_name = element_name + alt_suffix + + return os.path.join(project_dir, element_name) + + +def _parse_output_keys(output): + # Returns an OrderedDict of element names + # and their cache keys + # + actual_keys = OrderedDict() + lines = output.splitlines() + for line in lines: + split = line.split("::") + name = split[0] + key = split[1] + actual_keys[name] = key + + return actual_keys + + +def _load_expected_keys(project_dir, actual_keys, raise_error=True): + # Returns an OrderedDict of element names + # and their cache keys + # + expected_keys = OrderedDict() + for element_name in actual_keys: + expected = _element_filename(project_dir, element_name, "expected") + try: + with open(expected, "r") as f: + expected_key = f.read() + expected_key = expected_key.strip() + except FileNotFoundError: + expected_key = None + if raise_error: + raise Exception( + "Cache key test needs update, " + + "expected file {} not found.\n\n".format(expected) + + "Use python3 -m buildstream.testing._update_cachekeys in the" + + " project's directory to automatically update this test case" + ) + + expected_keys[element_name] = expected_key + + return expected_keys + + +def _assert_cache_keys(project_dir, output): + # Read in the expected keys from the cache key test directory + # and parse the actual keys from the `bst show` output + # + actual_keys = _parse_output_keys(output) + expected_keys = _load_expected_keys(project_dir, actual_keys) + mismatches = [] + + for element_name in actual_keys: + if actual_keys[element_name] != expected_keys[element_name]: + mismatches.append(element_name) + + if mismatches: + info = "" + for element_name in mismatches: + info += ( + " Element: {}\n".format(element_name) + + " Expected: {}\n".format(expected_keys[element_name]) + + " Actual: {}\n".format(actual_keys[element_name]) + ) + + raise AssertionError( + "Cache key mismatches occurred:\n{}\n".format(info) + + "Use python3 -m buildstream.testing._update_cachekeys in the project's" + + "directory to automatically update this test case" + ) |