Test Framework

The tenzir-test harness discovers and runs integration tests for pipelines, fixtures, and custom runners. Use this page as a reference for concepts, configuration, and CLI details. For step-by-step walkthroughs, see the guides for writing tests, creating fixtures, and adding custom runners.

Install

tenzir-test ships as a Python package that requires Python 3.12 or later. Install it with uv (or pip) and verify the console script:

uv add tenzir-test
uvx tenzir-test --help

Core concepts

• Project root – Directory passed to --root; typically contains fixtures/, inputs/, runners/, and tests/.
• Mode – Auto-detected as project or package. A package.yaml in the current directory (or its parent when you run from <package>/tests) switches to package mode.
• Test – Any supported file under tests/; frontmatter controls execution.
• Runner – Named strategy that executes a test (tenzir, python, custom entries).
• Fixture – Reusable environment provider registered under fixtures/ and requested via frontmatter.
• Suite – Directory-owned group of tests that share fixtures and run sequentially. Declare it with suite: in a test.yaml; all descendants join automatically.
• Input – Data accessed with TENZIR_INPUTS; defaults to <root>/inputs but you can override it per directory or per test with an inputs: setting.
• Scratch directory – Ephemeral workspace exposed as TENZIR_TMP_DIR during each test run.
• Artifact / Baseline – Runner output persisted next to the test; regenerate with --update.
• Configuration sources – Frontmatter plus inherited test.yaml files; tenzir.yaml still configures the Tenzir binary.

A typical project layout looks like this:

project-root/
├── fixtures/
│   └── __init__.py
├── inputs/
│   └── sample.ndjson
├── runners/
│   └── __init__.py
└── tests/
    ├── alerts/
    │   ├── sample.tql
    │   └── sample.txt
    └── python/
        └── quick-check.py

For a package layout (with package.yaml), the structure may look like:

my-package/
├── package.yaml
├── operators/
│   └── custom-op.tql
├── pipelines/
│   └── smoke.tql
└── tests/
    ├── inputs/
    │   └── sample.ndjson
    ├── fixtures/
    │   └── __init__.py
    ├── runners/
    │   └── __init__.py
    └── pipelines/
        ├── custom-op.tql
        └── custom-op.txt

Execution modes and packages

• The harness treats --root as the project root. If that directory (or its parent when named tests) contains package.yaml, tenzir-test switches to package mode and exposes:
  • TENZIR_PACKAGE_ROOT – Absolute package directory.
  • TENZIR_INPUTS – <package>/tests/inputs/ unless a directory test.yaml or the test frontmatter overrides it.
  • --package-dirs=<package> – Passed automatically to the tenzir binary.
• Without a manifest the harness stays in project mode, recursively discovers tests under tests/, and applies global fixtures, runners, and inputs.

CLI reference

Run the tests from the project root:

uvx tenzir-test

Useful options:

• --tenzir-binary /path/to/tenzir: Override binary lookup.
• --tenzir-node-binary /path/to/tenzir-node: Override node binary path.
• --update: Rewrite reference artifacts next to each test.
• --purge: Remove generated artifacts (diffs, text outputs) from previous runs.
• --jobs N: Control concurrency (4 * CPU cores by default).
• --coverage and --coverage-source-dir: Enable LLVM coverage.
• -k, --keep: Preserve per-test scratch directories instead of deleting them (same as setting TENZIR_KEEP_TMP_DIRS=1).
• --debug: Emit framework-level diagnostics (fixture lifecycle, discovery notes, comparison targets, etc.). The same mode is available via TENZIR_TEST_DEBUG=1.
• --summary: Print the tabular breakdown and failure tree after each project.
• --diff/--no-diff: Toggle unified diff output for failed comparisons. Diffs are shown by default; disable them when you only need aggregated statistics.
• --diff-stat/--no-diff-stat: Show (or suppress) the per-file change counter, which summarises additions and deletions even when the diff body is hidden.
• -p, --passthrough: Stream raw stdout/stderr to the terminal instead of comparing against reference artifacts. The harness forces single-job execution (overriding --jobs when necessary) and ignores --update while passthrough is active.
• -a, --all-projects: Run the root project together with any satellites provided on the command line.

Set TENZIR_TEST_DEBUG=1 in CI when you want the same diagnostics without passing --debug on the command line.

Python API

The harness is also available as a typed Python library. Import tenzir_test and call execute() when you need to run scenarios from automation or another tool without shelling out to the CLI:

from pathlib import Path

from tenzir_test import ExecutionResult, execute

result: ExecutionResult = execute(tests=[Path("tests/pipeline.tql")])
if result.exit_code:
    # propagate non-zero status to your orchestration layer
    raise SystemExit(result.exit_code)
for project in result.project_results:
    print(project.selection.root, project.summary.total)

The helper mirrors the CLI options but returns an ExecutionResult with aggregated Summary objects and metadata you can inspect or serialize. Errors surface as HarnessError exceptions so callers can control reporting and retry logic.

Selections

A selection is the ordered list of positional paths you pass after the CLI flags. Each element can point to a single test file, a directory, or an entire project. The harness resolves every element relative to the current working directory first and then relative to the root project. How you shape the selection determines which projects run:

• No positional arguments → run every test in the root project.
• Paths inside the root project → run only those targets (plus any explicitly named satellites).
• Paths that resolve to satellite projects → run those satellites, skipping the root unless you also request it.

Use --all-projects when you want the root project to execute alongside a selection that only names satellites. This keeps the CLI predictable: the selection lists the exact satellites you care about, and the flag opts the root back in without duplicating its path on the command line.

Suites

Suites let you run several tests under one shared fixture lifecycle. Declare a suite in a directory-level test.yaml; the definition applies to every test under that directory, including nested subdirectories.

tests/http/test.yaml

suite: smoke-http
fixtures: [http]
timeout: 45

Key rules:

• Suites are directory-owned. Once a test.yaml sets suite, all descendants belong to that suite. Put tests that should remain independent outside the suite directory or in a sibling directory with a different suite.
• Per-test frontmatter may not declare suite.
• Suite members inherit the directory defaults and can still override most keys on a per-file basis. The exceptions are fixtures and retry, which must be defined at the directory level once a suite is active so every member agrees on the shared lifecycle. Outside suites you can still set those keys directly in frontmatter.
• The harness runs suite members sequentially in lexicographic order of their relative paths. Each suite occupies a single worker, but different suites can run in parallel when --jobs allows it.
• The CLI executes all suites before any remaining standalone tests so shared fixtures start and stop predictably.
• Run the directory that defines the suite (for example tenzir-test tests/http) when you want to focus on it. Selecting an individual member now raises an error so every run exercises the full lifecycle and shared fixtures stay in sync.

Run a subset of tests

uvx tenzir-test tests/alerts/high-severity.tql

You can list multiple paths in a single invocation. tenzir-test wires every argument into the same runner and fixture registry, so you can mix scenarios from the project and external checkouts:

uvx tenzir-test tests/alerts ../contrib/plugins/*/tests

Run multiple projects with one command

Pass additional project directories after --root to execute several projects in one go. Include --all-projects so the root executes next to its satellites. The directory given to --root acts as the root project; all other directories are treated as satellites:

uvx tenzir-test --root example-project --all-projects example-satellite

Key rules:

• The root project provides the baseline configuration (fixtures, runners, test.yaml defaults, inputs). Satellites layer their own fixtures and runners on top; duplicate names raise an error so conflicts surface early.
• Paths printed in the CLI summary are relative to the working directory. The harness announces each project before running it and lists the runner mix per project for quick insight.
• You can target subsets inside each project with additional positional arguments (tenzir-test --root main --all-projects secondary tests/smoke). When you skip --root entirely and only list satellite directories, the harness runs those satellites in isolation.
• Satellites keep their own tests/, inputs/, fixtures/, and runners/ folders. A root project can host shared assets that satellites reuse without duplication—for example, the example repository includes an example-satellite/ directory that consumes the xxd runner exported by the root project while defining a satellite-specific fixture.

To regenerate baselines while targeting a specific binary and project root:

TENZIR_BINARY=/opt/tenzir/bin/tenzir \
TENZIR_NODE_BINARY=/opt/tenzir/bin/tenzir-node \
uvx tenzir-test --root tests --update

Runners

Runner	Command/behavior	Input extension	Artifact
tenzir	tenzir -f <test>	.tql	.txt
python	Execute with the active Python runtime	.py	.txt
shell	sh -eu <test> via the harness helper	.sh	varies

Selection flow:

1. The harness chooses the first registered runner that claimed the file extension.
2. Default suffix mapping applies when no runner explicitly claims an extension: .tql → tenzir, .py → python, .sh → shell.
3. A runner: <name> frontmatter entry overrides the automatic choice.
4. If no runner claims the extension and none is specified in frontmatter, the harness fails with an error instead of guessing.

Shell runner

Place scripts (for example under tests/shell/) with the .sh suffix to run them under bash -eu via the shell runner. The harness also prepends <root>/_shell to PATH so project-specific helper binaries become discoverable. The runner captures stdout and stderr (like 2>&1) and compares the combined output with <test>.txt; run tenzir-test --update path/to/test.sh when you need to refresh the baseline.

Register custom runners in runners/__init__.py via tenzir_test.runners.register() or the @tenzir_test.runners.startup() decorator. Use replace=True to override a bundled runner or register_alias() to publish alternate names.

The runner guide contains a full example (XxdRunner).

Passthrough-aware subprocesses

When passthrough mode is active the harness streams stdout/stderr directly to the terminal and skips reference comparisons. Runner implementations can respect this automatically by spawning processes through tenzir_test.run.run_subprocess(...). The helper captures output when the harness needs it and inherits the parent descriptors otherwise. Pass force_capture=True when your runner must collect stdout even in passthrough mode. If you need to branch on the current behavior, call tenzir_test.run.get_harness_mode() or tenzir_test.run.is_passthrough_enabled().

The harness cycles between three internal modes:

• HarnessMode.COMPARE – default behavior; compare actual output with stored baselines.
• HarnessMode.UPDATE – engaged when you pass --update; runners should overwrite reference files.
• HarnessMode.PASSTHROUGH – enabled via -p/--passthrough; stream output directly without touching baselines.

get_harness_mode() returns the current enum value so custom runners can adapt logic if needed.

Configuration and frontmatter

tenzir-test merges configuration sources in this order (later wins):

1. Project defaults (test.yaml files, applied per directory).
2. Per-test frontmatter (YAML for .tql/.xxd, # key: value comments for Python and shell scripts).

Common frontmatter keys:

Key	Type	Default	Description
runner	string	by suffix	Runner name (tenzir, python, shell, custom).
fixtures	list of strings	[]	Requested fixtures; use fixture for a single value.
timeout	integer (s)	30	Command timeout. (--coverage multiplies it by five.)
error	boolean	false	Expect a non-zero exit code.
skip	string	unset	Mark the test as skipped (reason required).
inputs	string	project	Override TENZIR_INPUTS for this directory or test.
retry	integer	1	Total attempt budget for flaky tests (see below).

test.yaml files accept the same keys and apply recursively to child directories. A relative inputs: value resolves against the file that defines it, so inputs: ../data inside tests/alerts/test.yaml points at tests/data/. Frontmatter values follow the same rule and win over directory defaults. Adjacent tenzir.yaml files still configure the Tenzir binary; the harness appends --config=<file> automatically. The lookup keeps working even when you point the CLI at extra directories on the command line.

retry represents the total number of attempts the harness should make before declaring the test failed. Intermediate attempts stay quiet; the final outcome line includes attempts=N/M whenever the budget exceeds one. Keep the value small and treat it as a temporary guardrail while you fix the underlying flakiness.

Tenzir configuration files

• The harness inspects the directory that owns each test. If it finds tenzir.yaml, it appends --config=<path> to every invocation of the bundled tenzir/tql/diff runners. The path also seeds TENZIR_CONFIG unless you set that variable yourself. Custom runners that call the Tenzir binary should either use run.get_test_env_and_config_args(test) or honour the exported environment variables explicitly.
• The built-in node fixture uses the same discovery process and starts tenzir-node from the directory that owns the test file, so relative paths inside tenzir-node.yaml resolve against the test location. See the built-in node fixture section for precedence rules.
• This lets you keep one config for CLI-driven scenarios while passing a different config to the embedded node, for example to tweak endpoints or data directories independently.

Fixtures

Declaring fixtures

• List fixture names in frontmatter (fixtures: [node, http]). Importing the project fixtures package is enough to register custom fixtures thanks to the side effects in fixtures/__init__.py.
• The harness encodes requests in TENZIR_TEST_FIXTURES and exposes helper APIs in tenzir_test.fixtures:
  • fixtures() – Read-only view of active fixtures. Attribute access is supported, e.g. fixtures().node returns True if the fixture was requested and raises AttributeError otherwise.
  • acquire_fixture("name") – Manual controller for the named fixture. Use it as a context manager for automatic start()/stop() or call those methods explicitly to interleave lifecycle steps and optional hooks (for example kill() or restart()).
  • require("name") – Assert that a fixture was requested.
  • Executor() – Convenience wrapper that runs Tenzir commands with resolved binaries and timeout budget.

Example use from a Python helper:

from tenzir_test.fixtures import Executor

executor = Executor()
result = executor.run("from_file 'inputs/events.ndjson' | where severity >= 5\n")
assert result.returncode == 0

Built-in node fixture

• Request the fixture with fixtures: [node]; the harness will start tenzir-node with the binaries discovered for the current test.
• Configuration precedence:
  1. TENZIR_NODE_CONFIG in the environment.
  2. A tenzir-node.yaml placed next to the test file (exported automatically).
  3. The Tenzir defaults (no config file).
• The node process inherits the test directory as its current working directory, letting tenzir-node.yaml reference files with relative paths (for example state/ or schemas/).
• Each controller reuses its state and cache directories across start()/stop() cycles. By default they live under the per-test scratch directory (TENZIR_TMP_DIR/tenzir-node-*) and are removed once the fixture context ends. Starting a fresh controller (for example in another test run) yields a brand-new workspace.
• The fixture reuses other inherited arguments (for example --package-dirs=…) but replaces any existing --config= flag so the node process always honours the chosen configuration file.
• Tests can read TENZIR_NODE_CLIENT_ENDPOINT, TENZIR_NODE_CLIENT_BINARY, TENZIR_NODE_CLIENT_TIMEOUT, TENZIR_NODE_STATE_DIRECTORY, and TENZIR_NODE_CACHE_DIRECTORY from the environment to connect to the spawned node and inspect its working tree.
• Pipelines launched by the bundled Tenzir runners automatically receive --endpoint=<value> when this fixture is active, so they talk to the transient node without additional wiring.
• CLI and node configuration are independent: configure the CLI with tenzir.yaml and drop a tenzir-node.yaml (or set TENZIR_NODE_CONFIG) only when the node needs custom settings.

Registering fixtures

Implement fixtures in fixtures/ and register them with @tenzir_test.fixture(). Decorate a generator function, yield the environment mapping, and handle cleanup in a finally block:

from tenzir_test import fixture


@fixture()
def http():
    server = _start_server()
    try:
        yield {"HTTP_FIXTURE_URL": server.url}
    finally:
        server.stop()

@fixture also accepts regular callables returning dictionaries, context managers, or FixtureHandle instances for advanced scenarios.

The fixture guide demonstrates an HTTP echo server that exposes HTTP_FIXTURE_URL and tears down cleanly.

Environment variables

tenzir-test recognises the following environment variables:

• TENZIR_TEST_ROOT – Default test root when --root is omitted.
• TENZIR_BINARY / TENZIR_NODE_BINARY – Override binary discovery.
• TENZIR_INPUTS – Preferred data directory. Defaults to the project inputs folder but reflects any inputs: override from test.yaml or frontmatter.
• TENZIR_KEEP_TMP_DIRS – Keep per-test scratch directories (equivalent to --keep).
• TENZIR_TEST_DEBUG – Enable debug logging (equivalent to --debug).

Fixtures often publish additional variables (for example TENZIR_NODE_CLIENT_*, TENZIR_NODE_STATE_DIRECTORY, TENZIR_NODE_CACHE_DIRECTORY, HTTP_FIXTURE_URL).

During execution the harness also adds transient variables such as TENZIR_TMP_DIR so tests and fixtures can create temporary artifacts without polluting the repository. Combine it with --keep (or TENZIR_KEEP_TMP_DIRS=1) when you need to inspect the generated files after a run.

Baselines and artifacts

Regenerate reference output whenever behavior changes intentionally:

uvx tenzir-test --update

--purge removes stale artifacts (diffs, temporary files). Keep generated .txt files under version control so future runs can diff against them.

Troubleshooting

• Missing binaries – Ensure tenzir and tenzir-node are on PATH or set TENZIR_BINARY / TENZIR_NODE_BINARY explicitly.
• Unexpected exits – Set error: true in frontmatter when a non-zero exit is expected.
• Skipped tests – Use skip: reason to document temporary skips; baseline files can stay empty.
• Noisy output – Use --jobs 1 to serialize worker logs, and enable --debug (or set TENZIR_TEST_DEBUG=1) when you need to trace comparisons and fixture activity.

Further reading

• Write tests
• Create fixtures
• Add custom runners