Fixtures

pytest-libiio provides three public fixtures for accessing libiio hardware contexts in tests. All fixtures integrate with the @pytest.mark.iio_hardware marker to filter contexts by hardware name, and skip the test automatically when no matching hardware is found.

---

iio_uri

Scope: function

Returns a URI string for the first matching hardware context. If no context matches the @pytest.mark.iio_hardware marker (or no hardware is detected at all), the test is skipped.

When --iio-coverage is passed, this fixture starts per-test attribute coverage tracking automatically. When --telm is passed, telemetry collection is started and stopped around the test body.

Returns: str — a libiio URI such as "ip:192.168.1.1" or "usb:1.2.3"

Example:

import pytest
import iio


@pytest.mark.iio_hardware(["adrv9361", "pluto"])
def test_identify_device(iio_uri):
    ctx = iio.Context(iio_uri)
    assert ctx is not None

---

single_ctx_desc

Scope: function

Returns a single context-description dict for the first matching hardware context. The test is skipped if no matching context is found.

Returns: dict — see Context dict schema below.

Example:

import pytest
import iio


@pytest.mark.iio_hardware("adrv9361")
def test_device_drivers(single_ctx_desc):
    ctx = iio.Context(single_ctx_desc["uri"])
    assert single_ctx_desc["hw"] == "adrv9361"
    assert "ad9361-phy" in single_ctx_desc["devices"]

---

context_desc

Scope: function

Returns a list of all matching context-description dicts. This is useful when multiple boards of the same type are connected simultaneously. The test is skipped if no matching contexts are found.

Returns: list[dict] — each element follows the Context dict schema.

Example — multi-board pattern:

import pytest
import iio


@pytest.mark.iio_hardware("fmcomms2")
def test_all_boards(context_desc):
    for ctx_d in context_desc:
        ctx = iio.Context(ctx_d["uri"])
        phy = ctx.find_device("ad9361-phy")
        assert phy is not None

---

@pytest.mark.iio_hardware marker

The marker controls which hardware a test requires. It is optional — without it, context_desc returns all found contexts and no filtering is applied.

Usage	Behaviour
@pytest.mark.iio_hardware("pluto")	Accept only contexts whose hw key equals "pluto"
@pytest.mark.iio_hardware(["pluto", "adrv9361"])	Accept contexts matching any name in the list
@pytest.mark.iio_hardware("pluto", True)	Second arg True disables the test when running under --emu

Single hardware name:

@pytest.mark.iio_hardware("pluto")
def test_pluto_only(iio_uri):
    ctx = iio.Context(iio_uri)
    ...

Accept any of a list:

@pytest.mark.iio_hardware(["pluto", "adrv9361"])
def test_pluto_or_adrv(iio_uri):
    ctx = iio.Context(iio_uri)
    ...

Disable during emulation:

@pytest.mark.iio_hardware("pluto", True)
def test_real_hw_only(iio_uri):
    # This test is skipped when --emu is used
    ctx = iio.Context(iio_uri)
    ...

---

Context dict schema

Each context-description dict returned by context_desc and single_ctx_desc contains:

Key	Type	Example	Description
uri	str	"ip:192.168.1.1"	libiio connection URI
type	str	"ip"	Context transport type
devices	str	"ad9361-phy,cf-ad9361-lpc"	Comma-separated IIO driver names found in the context
hw	str	"adrv9361"	Hardware name resolved from the hardware map