TestContext

Test context providing test-specific utilities.

TestContext provides utilities for: - Screenshots: Capture views during tests - Timing: Measure operation performance - Assertions: Record pass/fail conditions - Logging: Test-specific notes

Tests call Slicer API directly - TestContext does NOT wrap Slicer functions.

Classes

class TestContext

Test execution context with test-specific utilities.

Provides: - output_folder: Path to current test run folder - screenshot(): Capture and save screenshots - timing(): Measure operation duration - assert_*(): Record test assertions

Does NOT provide wrappers for Slicer API. Tests should call Slicer functions directly (SampleData.downloadSample, slicer.mrmlScene, etc.).

Methods:

__init__()

Initialize test context.

output_folder()

Path to current test run output folder.

assertions()

List of assertions made during the test.

screenshots()

List of screenshot filenames captured during the test.

metrics()

Collected metrics for this test.

set_screenshot_context()

Set context metadata for subsequent screenshots.

screenshot()

Capture a screenshot of the current Slicer state (auto-numbered).

screenshot_slice_view()

Capture a screenshot of a specific slice view (auto-numbered).

screenshot_3d_view()

Capture a screenshot of the 3D view (auto-numbered).

timing()

Create a timing context for measuring operation duration.

record_metric()

Record a custom metric.

metric()

Record a custom metric (alias for record_metric).

log()

Log a test-specific note.

assert_true()

Assert that a condition is true.

assert_false()

Assert that a condition is false.

assert_equal()

Assert that two values are equal.

assert_not_equal()

Assert that two values are not equal.

assert_greater()

Assert that actual > expected.

assert_greater_equal()

Assert that actual >= expected.

assert_less()

Assert that actual < expected.

assert_less_equal()

Assert that actual <= expected.

assert_is_not_none()

Assert that a value is not None.

assert_is_none()

Assert that a value is None.

assert_almost_equal()

Assert that two values are approximately equal.

Functions

output_folder()

Path to current test run output folder.

assertions()

List of assertions made during the test.

screenshots()

List of screenshot filenames captured during the test.

metrics()

Collected metrics for this test.

set_screenshot_context()

Set context metadata for subsequent screenshots.

This metadata is stored in the manifest to document what each screenshot shows, without creating nested folders.

Usage:

ctx.set_screenshot_context(sample_data=”MRBrainTumor1”, algorithm=”watershed”) ctx.screenshot(“After 5 clicks”) # -> test_name/001.png with metadata

Args:

sample_data: Name of sample data being used. algorithm: Name of algorithm being tested. stage: Stage of the test (e.g., “setup”, “before_paint”, “after_paint”).

screenshot()

Capture a screenshot of the current Slicer state (auto-numbered).

Args:

description: Human-readable description of what the screenshot shows. doc_tags: Tags for documentation filtering (e.g., [“algorithm”, “watershed”]).

Screenshots with doc_tags are included in auto-generated documentation.

Returns:

ScreenshotInfo with path and metadata.

screenshot_slice_view()

Capture a screenshot of a specific slice view (auto-numbered).

Args:

view: View name (“Red”, “Yellow”, “Green”). description: Human-readable description. doc_tags: Tags for documentation filtering.

Returns:

ScreenshotInfo with path and metadata.

screenshot_3d_view()

Capture a screenshot of the 3D view (auto-numbered).

Args:

description: Human-readable description. doc_tags: Tags for documentation filtering.

Returns:

ScreenshotInfo with path and metadata.

timing()

Create a timing context for measuring operation duration.

Usage:

with ctx.timing(“watershed_stroke”):

effect.apply(…)

Args:

operation: Name of the operation being timed.

Returns:

Context manager that records duration on exit.

record_metric()

Record a custom metric.

Args:

name: Metric name (e.g., “voxel_count”, “dice_coefficient”). value: Metric value. unit: Optional unit string (e.g., “voxels”, “ms”).

metric()

Record a custom metric (alias for record_metric).

Args:

name: Metric name (e.g., “voxel_count”, “dice_coefficient”). value: Metric value. unit: Optional unit string (e.g., “voxels”, “ms”).

log()

Log a test-specific note.

Use for observations during test execution that may help with debugging or understanding test behavior.

Args:

message: Note to log.

assert_true()

Assert that a condition is true.

Args:

condition: Condition to check. message: Description of what is being checked.

Returns:

Assertion result.

assert_false()

Assert that a condition is false.

Args:

condition: Condition to check. message: Description of what is being checked.

Returns:

Assertion result.

assert_equal()

Assert that two values are equal.

Args:

actual: Actual value. expected: Expected value. message: Description of what is being checked.

Returns:

Assertion result.

assert_not_equal()

Assert that two values are not equal.

Args:

actual: Actual value. expected: Value that should not match. message: Description of what is being checked.

Returns:

Assertion result.

assert_greater()

Assert that actual > expected.

Args:

actual: Actual value. expected: Minimum threshold (exclusive). message: Description of what is being checked.

Returns:

Assertion result.

assert_greater_equal()

Assert that actual >= expected.

Args:

actual: Actual value. expected: Minimum threshold (inclusive). message: Description of what is being checked.

Returns:

Assertion result.

assert_less()

Assert that actual < expected.

Args:

actual: Actual value. expected: Maximum threshold (exclusive). message: Description of what is being checked.

Returns:

Assertion result.

assert_less_equal()

Assert that actual <= expected.

Args:

actual: Actual value. expected: Maximum threshold (inclusive). message: Description of what is being checked.

Returns:

Assertion result.

assert_is_not_none()

Assert that a value is not None.

Args:

value: Value to check. message: Description of what is being checked.

Returns:

Assertion result.

assert_is_none()

Assert that a value is None.

Args:

value: Value to check. message: Description of what is being checked.

Returns:

Assertion result.

assert_almost_equal()

Assert that two values are approximately equal.

Args:

actual: Actual value. expected: Expected value. delta: Maximum allowed difference. message: Description of what is being checked.

Returns:

Assertion result.