xref: /aosp_15_r20/build/bazel/scripts/difftool/diffs/context.py (revision 7594170e27e0732bc44b93d1440d87a54b6ffe7c)
1#!/usr/bin/env python3
2#
3# Copyright (C) 2022 The Android Open Source Project
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#   http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License."""
16
17import difflib
18import pathlib
19from diffs.diff import Diff, ExtractInfo
20
21
22class ContextDiff(Diff):
23  def __init__(self, tool: ExtractInfo, tool_name: str):
24    self.tool = tool
25    self.tool_name = tool_name
26
27  def diff(self, left_path: pathlib.Path, right_path: pathlib.Path) -> list[str]:
28    errors = []
29
30    left = self.tool(left_path)
31    right = self.tool(right_path)
32    comparator = difflib.context_diff(left, right)
33    difflines = list(comparator)
34    if difflines:
35      err = "\n".join(difflines)
36      errors.append(
37        f"{left_path}\ndiffers from\n{right_path}\nper {self.tool_name}:\n{err}")
38    return errors
39