Test Record

Understand the complete test record that OpenHTF produces after every test execution.

Every test execution produces a TestRecord — a structured object containing everything that happened: outcomes, measurements, phase results, logs, attachments, and diagnoses. Output callbacks receive this record to write JSON, send to a database, or integrate with systems like TofuPilot.

Test record structure

Test outcomes

Phase records

Each phase produces a PhaseRecord with its own outcome and measurements.

Metadata

Keyword arguments to htf.Test() end up in test_record.metadata. Use them for a part number, a firmware version, or anything a downstream tool needs. TofuPilot reads part_number, revision_number, batch_number and sub_units (plus procedure_id with upload()).

import openhtf as htf

def power_on(test):
    return htf.PhaseResult.CONTINUE

def main():
    test = htf.Test(
        power_on,
        test_name="PCB01 functional test",   # replaces the default "openhtf_test"
        part_number="PCB01",
        firmware="1.4.2",
    )
    test.execute(lambda: "SN1234")

if __name__ == "__main__":
    main()

config is reserved — OpenHTF fills it with the loaded configuration. Phases can add to the dictionary at run time through test.test_record.metadata[...], as shown below.

Accessing the record

You can access the test record directly within a phase through test.test_record, though this is generally discouraged in favor of using the test.measurements interface.

import openhtf as htf

def inspect_phase(test):
    # Access test-level metadata
    test.test_record.metadata['operator'] = 'Jane'

    # Check DUT ID
    test.logger.info('Testing DUT: %s', test.dut_id)

    return htf.PhaseResult.CONTINUE

def main():
    test = htf.Test(inspect_phase)
    test.execute(lambda: "SN1234")

if __name__ == "__main__":
    main()

JSON output

The most common way to inspect a test record is via JSON output. See Output Callbacks for details on writing test records to files.

import openhtf as htf
from openhtf.output.callbacks import json_factory

@htf.measures(htf.Measurement('voltage').in_range(3.0, 5.0))
def measure_voltage(test):
    test.measurements.voltage = 3.3

def main():
    test = htf.Test(measure_voltage)
    test.add_output_callbacks(
        json_factory.OutputToJSON('./test_result.json', indent=2)
    )
    test.execute(lambda: "SN1234")

if __name__ == "__main__":
    main()

The resulting JSON file contains the complete test record: DUT ID, station ID, outcome, all phase records with their measurements, logs, and timing data. Field-by-field documentation of that file is in the JSON format reference.

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