xref: /aosp_15_r20/external/bazelbuild-rules_testing/lib/private/file_subject.bzl (revision d605057434dcabba796c020773aab68d9790ff9f)

# Copyright 2023 The Bazel Authors. 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.

"""# FileSubject"""

load(":str_subject.bzl", "StrSubject")

def _file_subject_new(file, meta):
    """Creates a FileSubject asserting against the given file.

    Method: FileSubject.new

    Args:
        file: ([`File`]) the file to assert against.
        meta: ([`ExpectMeta`])

    Returns:
        [`FileSubject`] object.
    """

    # buildifier: disable=uninitialized
    public = struct(
        # keep sorted start
        equals = lambda *a, **k: _file_subject_equals(self, *a, **k),
        path = lambda *a, **k: _file_subject_path(self, *a, **k),
        short_path_equals = lambda *a, **k: _file_subject_short_path_equals(self, *a, **k),
        # keep sorted end
    )
    self = struct(file = file, meta = meta, public = public)
    return public

def _file_subject_equals(self, expected):
    """Asserts that `expected` references the same file as `self`.

    This uses Bazel's notion of [`File`] equality, which usually includes
    the configuration, owning action, internal hash, etc of a `File`. The
    particulars of comparison depend on the actual Java type implementing
    the `File` object (some ignore owner, for example).

    NOTE: This does not compare file content. Starlark cannot read files.

    NOTE: Same files generated by different owners are likely considered
    not equal to each other. The alternative for this is to assert the
    `File.path` paths are equal using [`FileSubject.path()`]

    Method: FileSubject.equals
    """

    if self.file == expected:
        return
    self.meta.add_failure(
        "expected: {}".format(expected),
        "actual: {}".format(self.file),
    )

def _file_subject_path(self):
    """Returns a `StrSubject` asserting on the files `path` value.

    Method: FileSubject.path

    Returns:
        [`StrSubject`] object.
    """
    return StrSubject.new(
        self.file.path,
        meta = self.meta.derive("path()"),
    )

def _file_subject_short_path_equals(self, path):
    """Asserts the file's short path is equal to the given path.

    Method: FileSubject.short_path_equals

    Args:
        self: implicitly added.
        path: ([`str`]) the value the file's `short_path` must be equal to.
    """
    path = self.meta.format_str(path)
    if path == self.file.short_path:
        return
    self.meta.add_failure(
        "expected: {}".format(path),
        "actual: {}".format(self.file.short_path),
    )

# We use this name so it shows up nice in docs.
# buildifier: disable=name-conventions
FileSubject = struct(
    new = _file_subject_new,
    equals = _file_subject_equals,
    path = _file_subject_path,
    short_path_equals = _file_subject_short_path_equals,
)