Writing tests¶

Familiarity with pytest is recommended.

Overview¶

This guide offers a quick overview and best practices specific to Salt extension development. For more details, refer to the pytest-salt-factories documentation.

Test types¶

There are three main categories of tests:

Unit

Purpose: Verify low-level or hard-to-reach behavior. Use as a fallback when other test types are too complex to implement.
Approach: Use patching and mocking to isolate the code under test.
Example applications: Exception handling, parsing, utility functions

Functional

Purpose: Validate that functionality works as expected in a realistic, but lightweight environment (no running Salt daemons). Represents the preferred way of testing, if possible.
Approach: Test modules in a typical environment. Lightweight patching is allowed, but not encouraged.
Example applications: Execution/State/Runner/SDB module tests

Integration

Purpose: Ensure functionality that depends on running daemons works correctly in a realistic environment.
Approach: Run modules using CLI command wrappers, simulating real-world conditions.
Example applications: Peer publishing, Salt Mine, Salt-SSH (wrapper modules), Reactor

Unit tests¶

Setup and basics¶

In your test files, you typically import the modules you want to test directly.

If your module does not reference any Salt-specific global dunders, you can call the function you want to test directly:

from saltext.foo.modules import bar


def test_bar_baz():
    res = bar.baz()
    assert res == "worked"

However, if your module uses Salt-specific global dunders like __salt__ or __opts__, these dunders won’t be defined yet because the module hasn’t been initialized by the Salt loader. Attempting to call such functions directly would result in a NameError.

To resolve this, define a configure_loader_modules fixture. This fixture returns a mapping of modules to initialize to dunder content overrides.

The overrides can be empty, which just ensures that the dunders are defined:

import pytest
from saltext.foo.modules import bar


@pytest.fixture
def configure_loader_modules():
    return {
        bar: {},
    }

If you need the __salt__ dunder to contain specific keys such as defaults.merge, and ensure the defaults module is properly initialized by the loader, you can define the fixture as follows:

import pytest
from salt.modules import defaults
from saltext.foo.modules import bar


@pytest.fixture
def configure_loader_modules():
    opts = {
        "value.for.test": True,
    }

    return {
        bar: {
            "__salt__": {
                "defaults.merge": defaults.merge,
            },
            "__opts__": opts,
        },
        defaults: {
            "__opts__": opts,
        },
    }

Common patterns¶

Unit tests usually rely on a subset of the following classes/functions:

Please see the unittest.mock docs for details.

Important fixtures¶

`minion_opts`¶

Scope: function
Description: Provides default __opts__ for unit tests requiring realistic Salt minion opts.

`master_opts`¶

Scope: function
Description: Provides default __opts__ for unit tests requiring realistic Salt master opts.

Functional tests¶

Setup and basics¶

Functional tests operate within a familiar Salt environment, so you don’t need to import the modules you’re testing. The loaders fixture provides access to most Salt module types.

For example, if you’re testing an execution module named foobar, you can access the initialized module like this:

import pytest


@pytest.fixture
def foobar_mod(loaders):
    # This also works with `states`, `runners` etc.
    return loaders.modules.foobar


def test_stuff(foobar_mod):
    res = foobar_mod.baz()
    assert res == "worked"

If your module requires specific Salt configurations in __opts__, you can define configuration overrides using the minion_config_overrides or master_config_overrides fixtures. These fixtures are scoped to the module, meaning they apply to all tests in the same file:

import pytest


@pytest.fixture(scope="module")
def minion_config_overrides():
    return {
        "my_conf": "val",
    }

Common patterns¶

Creating temporary files¶

You can create temporary files using pytest.helpers.temp_file, preferrably as a context manager:

import pytest
from textwrap import dedent


def test_stuff(tmp_path, loaders, minion_opts):
    file_name = "foo"
    file_contents = dedent(
        """
        {{ opts | json }}
        """
    ).strip()

    with pytest.helpers.temp_file(file_name, file_contents, tmp_path) as test_file:
        res = loaders.modules.slsutil.renderer(str(test_file))
        assert res == minion_opts

In this example, a temporary file is created, used, and cleaned up automatically within the test.

Tip

Temporary files are often created within fixtures, not the tests themselves. This separation of concerns improves code reuse and ensures that the actual tests are concise.

Testing state modules¶

Return value assertions¶

When calling state modules in a functional test, the return value is a wrapper around the standard dictionary return. You should access its properties using the following pattern:

def test_state_module(states):
    ret = states.my_state.present("foo")
    assert ret.result is True
    assert "as specified" in ret.comment
    assert not ret.changes

Test mode¶

State modules can also be called with test=True during functional tests:

def test_state_module_test(states):
    ret = states.my_state.present("foo", test=True)
    assert ret.result is None
    assert "would have" in ret.comment
    assert ret.changes

Important fixtures¶

`loaders`¶

Scope

function

Description

An instance of Loaders, provides access to Salt loaders for several module types via its attributes.

Example

loaders.modules.test.ping()

`modules`¶

Scope: function
Description: Shortcut for loaders.modules.

`states`¶

Scope: function
Description: Shortcut for loaders.states.

Integration tests¶

Setup and basics¶

Integration tests run within a familiar Salt environment, hence you don’t need to import the modules you’re testing. Instead, you can run your modules using specific fixtures that wrap familiar CLI commands.

These fixtures invoke a subprocess, so their return value is a wrapper around the command’s result:

def test_stuff(salt_call_cli):
    res = salt_call_cli.run("foobar.baz")
    # Ensure the execution did not error.
    assert res.returncode == 0
    # The actual return value is stored in the `data` attribute.
    # It is automatically hydrated into the appropriate Python type.
    assert res.data == {"worked": True}

If your modules require specific Salt configurations, you can override the Salt master or minion configuration in your project’s tests/conftest.py by defining a fixture named master_config or minion_config:

import pytest


@pytest.fixture(scope="package")
def master_config():
    return {
        "ext_pillar": [
            {"my_pillar": {}},
        ],
    }

Common patterns¶

Creating temporary state files¶

To test specific modules within the context of the state machinery, you can create a temporary state file in the Salt master’s file_roots:

from textwrap import dedent


def test_foobar_in_state_apply(salt_call_cli, master):
    sls = "foobar_test"
    file_contents = dedent(
        """
        Test this:
          foobar.present:
            - name: baz
        """
    )

    with master.state_tree.base.temp_file(f"{sls}.sls", file_contents):
        res = salt_call_cli.run("state.apply", sls)
        assert res.returncode == 0

Important fixtures¶

`salt_call_cli`¶

Scope

function

Description

Runs salt-call commands, typically used in most integration tests.

Example

res = salt_call_cli.run("state.highstate")
assert res.returncode == 0

`salt_run_cli`¶

Scope

function

Description

Runs salt-run commands, often used in runner integration tests or for setting up master fixtures (e.g. syncing the fileserver).

Example

res = salt_run_cli.run("fileserver.update")
assert res.returncode == 0
assert res.data is True

`salt_ssh_cli`¶

Scope

module

Description

Runs salt-ssh commands, usually for wrapper module tests. Available when the extension has enabled for wrapper loaders or ssh_fixtures.

Example

res = salt_ssh_cli.run("foobar.baz")
assert res.returncode == 0
assert res.data == {"worked": True}

`master`¶

Scope

package

Description

Provides an instance of saltfactories.daemons.master.SaltMaster. Example uses include inspecting the current master configuration or creating temporary files in the state/pillar tree.

Example

Temporary state file in base env

with master.state_tree.base.temp_file("file_name", "contents") as temp_sls:

Temporary pillar file in prod env

with master.pillar_tree.prod.temp_file("file_name", "contents") as temp_pillar:

`minion`¶

Scope

package

Description

Provides an instance of saltfactories.daemons.minion.SaltMinion. Example uses include inspecting the current minion configuration or creating temporary files in the state/pillar tree when file_client is set to local.

Temporary state file in prod env

with minion.state_tree.prod.temp_file("file_name", "contents") as temp_sls:

Temporary pillar file in base env

with minion.pillar_tree.base.temp_file("file_name", "contents") as temp_pillar:

Writing tests¶

Overview¶

Test types¶

Unit tests¶

Setup and basics¶

Common patterns¶

Important fixtures¶

minion_opts¶

master_opts¶

Functional tests¶

Setup and basics¶

Common patterns¶

Creating temporary files¶

Testing state modules¶

Return value assertions¶

Test mode¶

Important fixtures¶

loaders¶

modules¶

states¶

Integration tests¶

Setup and basics¶

Common patterns¶

Creating temporary state files¶

Important fixtures¶

salt_call_cli¶

salt_run_cli¶

salt_ssh_cli¶

master¶

minion¶

`minion_opts`¶

`master_opts`¶

`loaders`¶

`modules`¶

`states`¶

`salt_call_cli`¶

`salt_run_cli`¶

`salt_ssh_cli`¶

`master`¶

`minion`¶