Test tooling reference

← ReferenceTest tooling referenceTwo tables that answer 'does this feature work on my platform?' and 'which repo owns this?'. The feature support matrix lists where the three drivers agree and where they differ; the ownership table names the single source of truth for each moving part of the test toolchain.reference

Feature support matrixThe action / assert DSL is cross-platform: the core actions, all assertions (with auto-wait), `state` assertions via a state provider, and the `screenshot` visual-regression assert run on all three drivers. The rows below are where the drivers genuinely differ — verified against the driver source, not the READMEs.Where the drivers differ (source-verified):

support matrix

Feature                       | iOS                           | Android                   | Web
------------------------------+-------------------------------+---------------------------+------------------------
element id -> automation id   | accessibilityIdentifier       | resource-id (testTag)     | HTML id (#id)
screen marker (assert screen) | 0.5x0.5 centred overlay       | 1.dp Box, inset past bars | data-screen on the root
marker build gate             | #if DEBUG                     | app FLAG_DEBUGGABLE       | NODE_ENV != production
"is displayed" predicate      | exists && (hittable || alone) | findObject(By.res(...))   | attached && visible
pass / fail accessor          | result.allPassed              | TestSuiteResult.allPassed | allPassed(result)  [fn]
addMedia action               | PhotoKit seed (sim only)      | into the gallery          | sets a file input
emitHook action               | no-op + warning               | no-op + warning           | app-registered hooks
openedUrl assertion           | not supported                 | not supported             | window.open spy
tap.retryTapIfNoChange        | applied                       | applied                   | accepted, no-op
recordings                    | Xcode auto (failures)         | record=true, per case     | Playwright video config
launch.permissions            | UI-interruption monitor       | grant / deny->assert [fn3]| storage + cookies
launch.clearState             | clear-state env               | in-process wipe [fn2]     | cookies + storage
run the tests with            | xcodebuild test               | gradlew connectedAndroid  | npx playwright test
 
[fn]  a function the Web driver exports; iOS and Android read allPassed as a property on the result object
[fn2] wipes files, shared_prefs, databases, cache and code_cache from inside the process, then relaunches —
      persisted state only, process memory survives (driver 1.8.4; the previous `pm clear` force-stopped the
      instrumentation process running the tests, so the run died before reporting)
[fn3] allow is pm grant, as before; deny no longer revokes — the driver asserts the permission is already denied
      and fails the file when it is granted (driver 1.8.5; it declares that an in-run pm revoke kills the
      instrumented process, so it never executes one). Put the denied baseline in place before the run with
      `jsonui-test pregrant --platform android` (cli 1.8.0). unset leaves the inherited state untouched.

Source-of-truth ownershipThe test toolchain spans several repos, each owning exactly one thing. Schemas live in jsonui-test-runner; the CLI and its validator constants live in jsonui-cli; each driver is published from its own repo; and a drift-check test in jsonui-cli keeps the schemas and the validator constants in lockstep in CI.Who owns what:

ownership

Moving part                              | Source of truth
-----------------------------------------+------------------------------------------------
Test schemas (screen/actions/flow/       | jsonui-test-runner  (schemas/)
  results/description)                   |
Validator constants (schema.py/report.py)| jsonui-cli
jsonui-test CLI                          | jsonui-cli  (test_tools/, bundled with jui)
Drivers (iOS / Android / Web)            | each driver repo  (SPM / Maven Central / npm)
mock.schema.json                         | jsonui-test-runner  (editor/doc only)
schema <-> validator drift-check         | jsonui-cli CI  (test_schema_drift.py)

Keep reading

Writing screen testsThe DSL these tables describe./guides/testing

Mocking APIs in testsBackend-free testing with mock scenarios./guides/api-mock