1"""Library for constructing an Mbed TLS test case.
2"""
3
4# Copyright The Mbed TLS Contributors
5# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6#
7
8import binascii
9import os
10import sys
11from typing import Iterable, List, Optional
12
13from . import typing_util
14
15def hex_string(data: bytes) -> str:
16    return '"' + binascii.hexlify(data).decode('ascii') + '"'
17
18
19class MissingDescription(Exception):
20    pass
21
22class MissingFunction(Exception):
23    pass
24
25class TestCase:
26    """An Mbed TLS test case."""
27
28    def __init__(self, description: Optional[str] = None):
29        self.comments = [] #type: List[str]
30        self.description = description #type: Optional[str]
31        self.dependencies = [] #type: List[str]
32        self.function = None #type: Optional[str]
33        self.arguments = [] #type: List[str]
34
35    def add_comment(self, *lines: str) -> None:
36        self.comments += lines
37
38    def set_description(self, description: str) -> None:
39        self.description = description
40
41    def set_dependencies(self, dependencies: List[str]) -> None:
42        self.dependencies = dependencies
43
44    def set_function(self, function: str) -> None:
45        self.function = function
46
47    def set_arguments(self, arguments: List[str]) -> None:
48        self.arguments = arguments
49
50    def check_completeness(self) -> None:
51        if self.description is None:
52            raise MissingDescription
53        if self.function is None:
54            raise MissingFunction
55
56    def write(self, out: typing_util.Writable) -> None:
57        """Write the .data file paragraph for this test case.
58
59        The output starts and ends with a single newline character. If the
60        surrounding code writes lines (consisting of non-newline characters
61        and a final newline), you will end up with a blank line before, but
62        not after the test case.
63        """
64        self.check_completeness()
65        assert self.description is not None # guide mypy
66        assert self.function is not None # guide mypy
67        out.write('\n')
68        for line in self.comments:
69            out.write('# ' + line + '\n')
70        out.write(self.description + '\n')
71        if self.dependencies:
72            out.write('depends_on:' + ':'.join(self.dependencies) + '\n')
73        out.write(self.function + ':' + ':'.join(self.arguments) + '\n')
74
75def write_data_file(filename: str,
76                    test_cases: Iterable[TestCase],
77                    caller: Optional[str] = None) -> None:
78    """Write the test cases to the specified file.
79
80    If the file already exists, it is overwritten.
81    """
82    if caller is None:
83        caller = os.path.basename(sys.argv[0])
84    tempfile = filename + '.new'
85    with open(tempfile, 'w') as out:
86        out.write('# Automatically generated by {}. Do not edit!\n'
87                  .format(caller))
88        for tc in test_cases:
89            tc.write(out)
90        out.write('\n# End of automatically generated file.\n')
91    os.replace(tempfile, filename)
92