dds/tests/test_compile_deps.py

import subprocess

import pytest

from dds_ci.testing import ProjectOpener, Project
from dds_ci import proc, paths

## #############################################################################
## #############################################################################
## The test project in this directory contains a single application and two
## functions, each defined in a separate file. The two functions each return
## an integer, and the application exit code will be the difference between
## the two integers. (They are passed through std::abs(), so it is always a
## positive integer). The default value is 32 in both functions.
## #############################################################################
## The purpose of these tests is to ensure the reliability of the compilation
## dependency database. Having a miscompile because there was a failure to
## detect file changes is a catastrophic bug!


@pytest.fixture()
def test_project(project_opener: ProjectOpener) -> Project:
    return project_opener.open('projects/compile_deps')


def build_and_get_rc(proj: Project) -> int:
    proj.build()
    app = proj.build_root.joinpath('app' + paths.EXE_SUFFIX)
    return proc.run([app]).returncode


def test_simple_rebuild(test_project: Project) -> None:
    """
    Check that changing a source file will update the resulting application.
    """
    assert build_and_get_rc(test_project) == 0
    test_project.write('src/1.cpp', 'int value_1() { return 33; }')
    # 33 - 32 = 1
    assert build_and_get_rc(test_project) == 1


def test_rebuild_header_change(test_project: Project) -> None:
    """Change the content of the header which defines the values"""
    assert build_and_get_rc(test_project) == 0
    test_project.write('src/values.hpp', '''
        const int first_value = 63;
        const int second_value = 88;
    ''')
    assert build_and_get_rc(test_project) == (88 - 63)


def test_partial_build_rebuild(test_project: Project) -> None:
    """
    Change the content of a header, but cause one user of that header to fail
    compilation. The fact that compilation fails means it is still `out-of-date`,
    and will need to be compiled after we have fixed it up.
    """
    assert build_and_get_rc(test_project) == 0
    test_project.write('src/values.hpp', '''
        const int first_value_q  = 6;
        const int second_value_q = 99;
    ''')
    # Header now causes errors in 1.cpp and 2.cpp
    with pytest.raises(subprocess.CalledProcessError):
        test_project.build()
    # Fix 1.cpp
    test_project.write('src/1.cpp', '''
        #include "./values.hpp"

        int value_1() { return first_value_q; }
    ''')
    # We will still see a failure, but now the DB will record the updated values.hpp
    with pytest.raises(subprocess.CalledProcessError):
        test_project.build()

    # Should should raise _again_, even though we've successfully compiled one
    # of the two files with the changed `values.hpp`, because `2.cpp` still
    # has a pending update
    with pytest.raises(subprocess.CalledProcessError):
        test_project.build()

    # Pause long enough for timestamps to change
    test_project.write('src/2.cpp', '''
        #include "./values.hpp"

        int value_2() { return second_value_q; }
    ''')
    # We should now compile and link to get the updated value
    assert build_and_get_rc(test_project) == (99 - 6)