svg-pathdata/src/tests/remove_collinear.test.ts

Manipulate SVG path data (path[d] attribute content) simply and efficiently.

import { describe, test, expect } from '@jest/globals';

import { SVGPathData } from '../SVGPathData.js';

function testRemoveCollinear(path: string): string {
  const pathData = new SVGPathData(path).removeCollinear();
  return pathData.encode();
}

describe('Remove collinear points', () => {
  test('Horizontal line with collinear point', () => {
    expect(testRemoveCollinear('M10,10 L20,10 L30,10')).toEqual('M10 10L30 10');
  });

  test('Diagonal line with collinear point', () => {
    expect(testRemoveCollinear('M10,10 L20,20 L30,30')).toEqual('M10 10L30 30');
  });

  test('Vertical line with collinear point', () => {
    expect(testRemoveCollinear('M10,10 L10,20 L10,30')).toEqual('M10 10L10 30');
  });

  test('Multiple collinear sections', () => {
    expect(
      testRemoveCollinear(
        'M10,10 L20,10 L30,10 L40,20 L50,30 L60,40 L60,50 L60,60',
      ),
    ).toEqual('M10 10L30 10L60 40L60 60');
  });

  test('Preserves curves', () => {
    expect(
      testRemoveCollinear('M10,10 C20,20 30,20 40,10 L50,10 L60,10'),
    ).toEqual('M10 10C20 20 30 20 40 10L60 10');
  });

  test('Preserves closed paths', () => {
    expect(testRemoveCollinear('M10,10 L20,10 L30,10 L30,20 L10,20 Z')).toEqual(
      'M10 10L30 10L30 20L10 20z',
    );
  });

  test('Handles multiple subpaths', () => {
    expect(
      testRemoveCollinear('M10,10 L20,10 L30,10 M40,40 L50,40 L60,40'),
    ).toEqual('M10 10L30 10M40 40L60 40');
  });

  // Tests for relative paths
  test('Relative horizontal line with collinear point', () => {
    expect(testRemoveCollinear('m10,10 l10,0 l10,0')).toEqual('m10 10l20 0');
  });

  test('Relative diagonal line with collinear point', () => {
    expect(testRemoveCollinear('m10,10 l10,10 l10,10')).toEqual('m10 10l20 20');
  });

  test('Relative vertical line with collinear point', () => {
    expect(testRemoveCollinear('m10,10 l0,10 l0,10')).toEqual('m10 10l0 20');
  });

  test('Mixed relative and absolute commands', () => {
    expect(testRemoveCollinear('M10,10 L20,10 l10,0 l10,0')).toEqual(
      'M10 10l30 0',
    );
  });

  test('Relative multiple collinear sections', () => {
    expect(
      testRemoveCollinear(
        'm10,10 l10,0 l10,0 l10,10 l10,10 l10,10 l0,10 l0,10',
      ),
    ).toEqual('m10 10l20 0l30 30l0 20');
  });
});