IWC test data conventions

An IWC workflow test pairs each workflow with a sibling <workflow>-tests.yml. Each YAML test case supplies job: inputs under the workflow’s input labels and outputs: assertions under its output labels. The optional test-data/ directory holds local fixtures. These are the IWC contribution layout and Planemo test-format contracts. For decisions about the workflow interface before writing fixtures, see galaxy-workflow-testability-design. For the exact supported YAML vocabulary and static validation, see tests-format.

Examples below come from the cited IWC files or Planemo documentation. Corpus observations describe the workflows sampled for this note, not a rule that every IWC workflow follows.

Fixture locations and provenance

A class: File input can use path: for a local fixture or location: for a URI. Planemo resolves a relative path: from the workflow and test directory. IWC’s contribution guide recommends small inputs and suggests publishing a toy dataset to Zenodo for a permanent URL. The repository also permits an optional local test-data/ directory. It gives no universal size cutoff or mandatory host. Planemo input format, IWC contribution guide.

Large or variable outputs are better checked with targeted assertions than committed as full expected files, as the IWC guide recommends. planemo-asserts-idioms covers assertion choice. A test may mix local paths, remote locations, and scalar parameters in one job:.

- doc: Test with a published input
  job:
    Reference FASTA:
      class: File
      location: https://www.ebi.ac.uk/ena/browser/api/fasta/AF325528.1?download=true
      filetype: fasta
      hashes:
        - hash_function: SHA-1
          hash_value: 927d0d00b7db6ad60524bb9e50d3ab41c4ac5ecf
  outputs:
    result:
      asserts:
        has_text:
          text: expected-marker

The Reference FASTA file block is from the sampled IWC virology/pox-virus-amplicon/pox-virus-half-genome-tests.yml. The surrounding test case and output are illustrative. filetype: names a Galaxy datatype. The hashes: list records input integrity, including the algorithm and digest. SHA-1 is common in the sampled IWC inputs, but the vendored test-format schema also permits MD5, SHA-256, and SHA-512. Record a digest only after computing or verifying it against the actual file. Local paths may also carry hashes. Do not infer a hash merely from a URL or assume invocation generation was its source.

Input hashes: and output checksum: serve different purposes. Planemo documents output checksums, as well as file: comparisons and content assertions. The sampled IWC tests favored the latter forms, but that observation does not remove checksum: from the format.

Collection inputs

An explicit collection names its shape with collection_type: and gives each element an identifier:. Match the workflow’s declared input type and use identifiers that the workflow and output assertions can address. The Planemo collection examples show both a list and a nested list:paired.

job:
  samples:
    class: Collection
    collection_type: list
    elements:
      - identifier: sample_a
        class: File
        path: test-data/sample_a.fastq.gz
        filetype: fastqsanger.gz
      - identifier: sample_b
        class: File
        path: test-data/sample_b.fastq.gz
        filetype: fastqsanger.gz

The IWC short-read QC test uses the nested form. The outer collection is list:paired, each outer element is a Collection with a sample identifier:, and the two files are identified as forward and reverse:

job:
  Raw reads:
    class: Collection
    collection_type: list:paired
    elements:
      - class: Collection
        identifier: pair
        elements:
          - class: File
            identifier: forward
            location: https://zenodo.org/records/11484215/files/paired_r1.fastq.gz
            filetype: fastqsanger.gz
          - class: File
            identifier: reverse
            location: https://zenodo.org/records/11484215/files/paired_r2.fastq.gz
            filetype: fastqsanger.gz

Only the outer collection declares collection_type:. Galaxy derives each inner element’s type by splitting it on the first :, so an inner collection_type: (the IWC file carries a redundant collection_type: paired) is ignored, and type: is rejected by tests-format. A bare paired collection uses the inner shape without the outer list. For deeper collections, keep each level’s identifiers aligned with the workflow input. Check the resulting YAML against tests-format and the concrete workflow. The sampled IWC tests also contain nested output assertions: an output collection’s element_tests: selects an outer identifier, then a nested element_tests: selects inner identifiers. See the sampled scRNAseq/fastq-to-matrix-10x/scrna-seq-fastq-to-matrix-10x-cellplex-tests.yml and planemo-asserts-idioms.

Planemo also accepts a plain YAML list of File objects as a simple Galaxy list. That shorthand gives no control over element identifiers. Use the explicit collection form when names or a non-list shape matter. Do not treat an absence from a sample of IWC tests as a parser restriction.

A collection element’s identifier: is distinct from the workflow input label used as the job: key. Preserve meaningful, stable identifiers when downstream outputs or tests refer to them. Quote YAML mapping keys where required by YAML syntax. In a paired collection, the member identifiers are forward and reverse. An outer list:paired element can have a sample identifier such as pair. The Planemo nested example shows this distinction.

Other documented input forms

The Planemo composite-input example specifies composite_data: as a list of local path: objects, for example an imzML file plus its .ibd companion. The documentation says URI components are not tested there. The sampled IWC tests did not provide a composite example, so validate an actual composite case before relying on it.

job:
  imaging input:
    class: File
    filetype: imzml
    composite_data:
      - path: test-data/Example_Continuous.imzML
      - path: test-data/Example_Continuous.ibd

Planemo also documents tags: on collection elements. File attributes such as dbkey: and decompress: appear in the vendored test-format schema. These are available vocabulary, not requirements for every fixture. Use them when the workflow or data import needs them, then validate the concrete test.

Data-table values and built-in indexes

A workflow input selecting an installed reference index takes a scalar value from the relevant Galaxy data table. For example, the IWC contribution guide’s Bowtie2 example maps the displayed hg38 index to the plain value hg38 from bowtie2_indices.loc:

job:
  reference genome: hg38

The value column depends on the tool and table definition. Check that tool’s tool_data_table_conf.xml and the target instance’s available table entries. This input is a parameter, not a class: File fixture. IWC says its default CI Galaxy has CVMFS for built-in indexes. A local or other Galaxy instance must expose the same table value and underlying reference data for this test to run. A portable file input is possible only if the workflow interface and tool accept a file in place of the built-in index. Do not replace the scalar with class: File solely in the test YAML.

Authoring and checking an IWC test

IWC permits hand-written cases and documents planemo workflow_test_init <workflow.ga> for a blank template. A successful Galaxy invocation can seed a more complete test with planemo workflow_test_init --from_invocation .... Inspect generated paths, labels, hashes, and output comparisons before retaining them. IWC recommends assertions in place of large or unstable exact-output files. It also documents planemo workflow_lint, planemo test, and planemo workflow_test_on_invocation for checking a test against a saved invocation. IWC testing instructions, Planemo workflow best practices.

IWC’s preferred PR test runs on a Galaxy instance started by the GitHub Actions worker. Its contribution guide describes an external instance via .wt_instance as a last resort when required infrastructure or reference data cannot reasonably be made available in CI. That is a workflow-specific exception, not an implication of every CVMFS-backed test. Before running a test elsewhere, verify that the instance has the required tools, datatypes, data tables, and reference data.

Related references

• galaxy-workflow-testability-design — choose stable workflow labels, collection types, and output checkpoints.
• planemo-asserts-idioms — choose output checks and tolerances.
• implement-galaxy-workflow-test — turn a test plan and resolved data references into a test file.
• tests-format — exact Foundry schema and validator for the YAML format.
• IWC workflow contribution guide and Planemo test format — upstream contracts.