pytest-strawberry

Pytest plugin for Strawberry GraphQL

pytest-strawberry measures which Strawberry GraphQL schema fields are reached while your pytest suite runs. It reports schema field coverage independently of Python source coverage.

Installation

pip install pytest-strawberry

Pytest loads the plugin automatically through its pytest11 entry point.

Field coverage

Enable coverage on the pytest command line:

pytest --strawberry-coverage

By default, the report covers fields with explicit Strawberry resolvers, runtime field extensions, or custom field resolution supplied by integrations such as Strawberry Django. It excludes fields handled only by Strawberry's ordinary attribute lookup:

============================= Strawberry coverage =============================
Subscriptions: excluded (requires graphql-core 3.3+); graphql-core 3.2.11

Schema b6016cac
┌───────────────────┬────────┬──────┬─────────┬───────────────────────┐
│ Python type       │ Fields │ Miss │   Cover │ Missing fields        │
├───────────────────┼────────┼──────┼─────────┼───────────────────────┤
│ QueryRoot [Query] │      2 │    0 │ 100.00% │                       │
│ UserModel [User]  │      3 │    1 │  66.67% │ email_address [email] │
├───────────────────┼────────┼──────┼─────────┼───────────────────────┤
│ All types         │      5 │    1 │  80.00% │                       │
└───────────────────┴────────┴──────┴─────────┴───────────────────────┘

Overall coverage: 80.00% (4/5 fields, 1 missing)

The table uses Python class and field names so uncovered resolvers are directly searchable in the codebase. When name= explicitly changes a GraphQL name, the GraphQL alias is shown in brackets. Automatic camel-casing is not repeated.

Use all mode to include Strawberry fields that use default attribute resolution:

pytest --strawberry-coverage --strawberry-coverage-mode=all

A field counts as covered when GraphQL execution reaches its resolver or default lookup. A resolver that raises still counts. Fields skipped by a directive, omitted from the operation, or bypassed by null propagation do not. Aliases and fragments do not create additional field coordinates.

You can enforce a minimum combined percentage:

pytest --strawberry-coverage --strawberry-coverage-fail-under=90

The threshold is compared with the displayed percentage rounded to two decimal places. Mode, threshold, and HTML options require --strawberry-coverage.

HTML report

Write the same coverage data to a self-contained HTML report:

pytest --strawberry-coverage --strawberry-coverage-html=htmlstrawberry

Open htmlstrawberry/index.html in a browser. The responsive report opens with the overall percentage, uses Python-first names, and groups compact single-line field rows under their type. Clear green and red rows distinguish covered and missing fields, and missing fields are also labeled in text so the state survives printing. In resolver mode, fields using ordinary attribute lookup can be shown as muted yellow-gray not counted rows for context while remaining excluded from coverage totals. Checkboxes can hide fully covered types or reveal those excluded fields without JavaScript. For declarations inside the pytest project root, the type header shows the Python file and each field shows its definition line.

Fields wired through an external resolver, resolver factory, lambda, or user-defined field extension also include a compact via ... hint. Ordinary inline methods and framework-generated fields remain unannotated, keeping the report focused on wiring that may not be obvious from Python source coverage. The report follows the operating system's light or dark appearance and includes all styles without external assets. Column labels and the current type remain visible while scrolling long reports. A custom output directory can be passed after =. The terminal report remains enabled.

Schema executions with different field sets or Python mappings receive separate fingerprinted tables. Executions with the same field set are combined. The final threshold uses their combined field and hit totals. Coverage from pytest-xdist workers is merged automatically.

A runnable Strawberry Django example shows how generated model fields participate in resolver coverage without adding a runtime dependency on Strawberry Django.

Subscriptions

Subscription resolver extensions are supported by graphql-core 3.3 and newer. With that capability available, subscription source and payload fields are included normally. graphql-core 3.2 does not run resolver extensions for subscriptions, so subscription-only fields are excluded and the plugin emits one warning if a subscription executes. Query and mutation coverage remains available in the same run.

Only schemas used to execute an operation during the pytest session are reported. An observed schema with no eligible fields is 100% covered; a session that observes no schemas is 0% covered. Reporting and threshold enforcement are disabled under --collect-only.

Development

Install the project and its development dependencies with uv:

uv sync

Run the checks with:

uv run pytest
uv run ruff check .
uv run ruff format --check .
uv run mypy
uv build

Run the Strawberry, graphql-core, and Strawberry Django compatibility checks on Python 3.14 with:

uv run nox --tags compatibility

Releases

Release changes are proposed through pull requests containing a RELEASE.md. After the pull request is merged into main, AutoPub prepares and publishes the release.

Licensing

The code in this project is licensed under the MIT license. See LICENSE for more information.