ignition-testing

Ignition Testing Framework Reference

This project uses a custom Jython test framework that runs on the Ignition gateway. Tests execute in the gateway's script context with full access to system.* APIs, real tags, and database connections.

Architecture

• Test scripts live in ignition/script-python/ as __tests__/code.py inside any package
• Test framework (testing.* modules) may live in this project or be inherited from a parent project
• WebDev endpoints (testing/run, testing/tags) are always project-scoped — each project has its own
• Test runner discovers __tests__/code.py files by walking the filesystem, imports them, and executes @test-decorated functions

Writing Tests

File placement convention (IMPORTANT)

Tests go inside the package they test as a __tests__ subdirectory. Never create standalone top-level test packages.

CORRECT — tests live inside the package:
ignition/script-python/core/util/__tests__/code.py          → tests core.util
ignition/script-python/core/mes/changeover/__tests__/code.py → tests core.mes.changeover
ignition/script-python/core/networking/__tests__/code.py     → tests core.networking

WRONG — never do this:
ignition/script-python/testing_smoke/__tests__/code.py       → standalone test package with no matching code
ignition/script-python/tests/__tests__/code.py               → standalone tests directory

The runner discovers modules by path: core.mes.changeover.__tests__. This naming makes it obvious what each test module covers.

If you need a smoke test that tests the framework itself (not any specific package), put it in an existing utility package like core/util/__tests__/ or ask the user which package it should live in.

Test file structure

Create ignition/script-python/<package>/__tests__/code.py with a matching resource.json:

from testing.decorators import test, skip, setup, teardown, expected_error
from testing.assertions import assert_equal, assert_true, assert_not_none, assert_raises

@setup
def setup_module():
    """Runs once before all tests in this module."""
    pass

@teardown
def teardown_module():
    """Runs once after all tests in this module."""
    pass

@test
def test_basic_logic():
    result = 2 + 2
    assert_equal(result, 4, "basic math works")

@test
def test_tag_value():
    from testing.assertions import assert_tag_value
    assert_tag_value("[default]Path/To/Tag", 42.0)

@test
def test_system_call():
    result = system.tag.readBlocking(["[default]Some/Tag"])[0]
    assert_not_none(result.value, "tag should have a value")
    assert_true(result.quality.isGood(), "tag quality should be good")

@skip("waiting on PLC config")
@test
def test_not_ready_yet():
    pass

@expected_error(ValueError)
@test
def test_bad_input():
    int("not a number")

The resource.json alongside code.py:

{
  "scope": "A",
  "version": 1,
  "restricted": false,
  "overridable": true,
  "files": ["code.py"],
  "attributes": {
    "lastModification": {
      "actor": "external",
      "timestamp": "2026-01-01T00:00:00Z"
    }
  }
}

testing.decorators

Decorator	Purpose
@test	Marks a function as a test case. Runner discovers functions with _is_test = True.
@skip(reason="")	Skips the test. Apply BEFORE @test: @skip("reason") @test def ...
@setup	Module-level setup — runs once before all tests. Only one per module.
@teardown	Module-level teardown — runs once after all tests. Only one per module.
@expected_error(ExceptionType)	Test passes if the given exception is raised, fails otherwise.

testing.assertions

Function	Purpose
assert_equal(actual, expected, msg=None)	actual == expected
assert_not_equal(actual, expected, msg=None)	actual != expected
assert_true(val, msg=None)	val is truthy
assert_false(val, msg=None)	val is falsy
assert_none(val, msg=None)	val is None
assert_not_none(val, msg=None)	val is not None
assert_close(actual, expected, tolerance=0.001, msg=None)	Floating point comparison within tolerance
assert_raises(callable_fn, exception_type, msg=None)	callable_fn() raises exception_type. Returns the caught exception.
assert_tag_value(tag_path, expected, msg=None)	Reads a real gateway tag and asserts its value. Uses system.tag.readBlocking.
assert_contains(container, item, msg=None)	item in container
assert_isinstance(obj, expected_type, msg=None)	isinstance(obj, expected_type)

All raise TestAssertionError (subclass of AssertionError) with actual and expected attributes for structured reporting.

testing.helpers

Function	Purpose
write_dataset_tag(tag_path, columns, types, rows)	Create a real Ignition DataSet via system.dataset.toDataSet() and write to tag. Auto-reconfigures tag type if needed. Types: String, Float8, Int4, Boolean, DateTime.
clear_dataset_tag(tag_path, columns, types)	Write an empty DataSet to a tag (cleanup).

testing.runner

Function	Purpose
run_all(base_package="")	Discover and run all __tests__ modules. Optional base_package filter (e.g., "core.mes").
run_module(module_path)	Run a specific module (e.g., "core.mes.changeover.__tests__").

Returns structured dict:

{
    "passed": int, "failed": int, "skipped": int, "errors": int,
    "total": int, "duration_ms": int,
    "modules": [{"module": "...", "results": [{"name": "...", "status": "passed|failed|skipped|error", "message": "...", "duration_ms": int}]}]
}

testing.reporter

Function	Purpose
to_json(results)	JSON string
to_console(results)	Human-readable text for Script Console
to_junit_xml(results)	JUnit XML for CI integration

Running Tests

From Script Console:

print testing.runner.run_all()
print testing.runner.run_module("core.mes.changeover.__tests__")
print testing.reporter.to_console(testing.runner.run_all())

Via HTTP (WebDev endpoints):

# Discover modules
curl -k -s "https://localhost:9043/system/webdev/<PROJECT>/testing/run?discover=true"

# Run all
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/run"

# Run specific module
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/run?module=core.mes.changeover.__tests__"

# Run by package prefix
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/run?package=core.mes"

# Output formats: json (default), junit, text
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/run?format=text"

HTTP response codes: 200 = all passed, 207 = failures/errors, 500 = runner error.

testing/tags Endpoint

Read/write tags from E2E tests or external tools:

# Read tags
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/tags" \
  -H "Content-Type: application/json" \
  -d '{"reads": ["[WHK01]Path/To/Tag"]}'

# Write tags (auto-creates if missing)
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/tags" \
  -H "Content-Type: application/json" \
  -d '{"writes": [{"path": "[default]Test/Tag", "value": 42}]}'

# Call a gateway script function
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/tags" \
  -H "Content-Type: application/json" \
  -d '{"script": {"path": "core.util.secrets.get_secret", "args": ["mes-host"]}}'

# Delete tags (cleanup)
curl -k -s -X POST "https://localhost:9043/system/webdev/<PROJECT>/testing/tags" \
  -H "Content-Type: application/json" \
  -d '{"deleteTags": "[default]Test/Tag"}'

Test Discovery Convention

The runner walks ignition/script-python/ looking for directories named __tests__ or __TESTS__ containing code.py. The dotted module path is derived from the filesystem path:

ignition/script-python/core/mes/changeover/__tests__/code.py
→ module path: core.mes.changeover.__tests__

CRITICAL: resource.json Required for Test Modules

Every directory in ignition/script-python/ MUST have a resource.json alongside code.py — see the full resource.json reference in the ignition-api skill. Without it, Ignition silently ignores the module and imports fail with No module named ....

When creating a new test module, create resource.json for BOTH the package AND __tests__:

ignition/script-python/my_package/
├── code.py           # Package code
├── resource.json     # ← REQUIRED — use scope "A" template
└── __tests__/
    ├── code.py       # Test code
    └── resource.json # ← REQUIRED — use scope "A" template

If a test module import fails with No module named ..., check resource.json exists in every directory in the module path first. This is the #1 cause of test discovery failures.

Project Inheritance

In projects that inherit from a parent:

• Test framework (testing.*) — inherited automatically, lives in parent only
• Test modules (__tests__/code.py) — can exist in both parent and child; runner discovers all
• WebDev endpoints — NOT inherited, each project needs its own testing/run and testing/tags

Runner discovery and child project tests

The test runner discovers __tests__ modules by walking the gateway filesystem. The scaffolded runner (from this plugin) dynamically scans all projects in the gateway's data directory, so it finds tests in both parent and child projects automatically.

However, if the parent project has an older runner (pre-scaffold, hardcoded paths), it will only find tests in its own project. Child project tests won't be discovered.

When a user adds tests to a child project and they aren't discovered, ASK THE USER:

"The test runner in your parent project ({parent_name}) only scans its own script library. Your child project's __tests__ modules won't be discovered. Two options:

1. Update the parent runner — Replace testing/runner/code.py in {parent_name} with the updated version that dynamically discovers all projects. This fixes it for every child project.
2. Override the runner in this project — Create testing/runner/code.py here with dynamic discovery. This project gets its own runner without touching the parent.

Which do you prefer?"

If they choose option 2, scaffold the runner locally (don't use --skip-scripts, or copy just the runner module). If they choose option 1, update the parent's runner code.

Common Patterns

Testing a script function that reads tags:

@test
def test_get_area_state():
    from core.mes.changeover import client
    result = client.get_state("cooker")
    assert_not_none(result, "should return state dict")
    assert_contains(result, "current_state")

Testing with tag setup/teardown:

@setup
def setup_module():
    from testing.helpers import write_dataset_tag
    write_dataset_tag("[default]Test/Queue", ["Id", "Value"], ["String", "Int4"], [["A", 1], ["B", 2]])

@teardown
def teardown_module():
    from testing.helpers import clear_dataset_tag
    clear_dataset_tag("[default]Test/Queue", ["Id", "Value"], ["String", "Int4"])

@test
def test_queue_processing():
    qv = system.tag.readBlocking(["[default]Test/Queue"])[0]
    ds = qv.value
    assert_equal(ds.getRowCount(), 2)