Back to Repositories

Testing Measurement System Components in Textualize/rich

A comprehensive test suite for Rich’s measurement functionality, focusing on text rendering and dimension calculations. The tests verify measurement operations, handle edge cases for non-renderable content, and validate dimension clamping behaviors.

Test Coverage Overview

The test suite provides thorough coverage of Rich’s measurement system, including span calculations, renderable validation, and dimension clamping.

Tests span calculation accuracy for text measurements
Validates error handling for non-renderable content
Verifies measurement operations with zero-width conditions
Covers dimension clamping with various boundary conditions

Implementation Analysis

The testing approach utilizes pytest fixtures and assertions to validate measurement functionality. Tests employ a combination of direct measurement validation and error condition verification.

Uses pytest’s raise context manager for error testing
Implements console options manipulation for width testing
Employs systematic boundary testing for clamp operations

Technical Details

Testing Framework: pytest
Key Classes: Measurement, Console, Text
Error Handling: NotRenderableError
Test Utilities: Console options, measurement calculations

Best Practices Demonstrated

The test suite exemplifies robust testing practices with clear separation of concerns and comprehensive edge case coverage.

Isolated test cases for specific functionality
Explicit error condition validation
Comprehensive boundary testing
Clean test method organization

textualize/rich

tests/test_measure.py

            
from rich.text import Text
import pytest

from rich.errors import NotRenderableError
from rich.console import Console
from rich.measure import Measurement, measure_renderables


def test_span():
    measurement = Measurement(10, 100)
    assert measurement.span == 90


def test_no_renderable():
    console = Console()
    text = Text()

    with pytest.raises(NotRenderableError):
        Measurement.get(console, console.options, None)


def test_measure_renderables():
    console = Console()
    assert measure_renderables(console, console.options, "") == Measurement(0, 0)
    assert measure_renderables(
        console, console.options.update_width(0), "hello"
    ) == Measurement(0, 0)


def test_clamp():
    measurement = Measurement(20, 100)
    assert measurement.clamp(10, 50) == Measurement(20, 50)
    assert measurement.clamp(30, 50) == Measurement(30, 50)
    assert measurement.clamp(None, 50) == Measurement(20, 50)
    assert measurement.clamp(30, None) == Measurement(30, 100)
    assert measurement.clamp(None, None) == Measurement(20, 100)