lucid-ui/src/util/chart-helpers.spec.ts

A UI component library from AppNexus.

/* eslint-disable comma-spacing */
import _ from 'lodash';
import assert from 'assert';
import {
	byFields,
	minByFields,
	maxByFields,
	maxByFieldsStacked,
	discreteTicks,
	groupByFields,
	stackByFields,
	extractFields,
	transformFromCenter,
	nearest,
} from './chart-helpers';

describe('chart-helpers', () => {
	// Testing `formatDate` will require us to mock our time zone. Since the
	// function was taken from d3, I'm going to leave out testing it since the
	// value isn't worth the cost of adding a time mocking library.
	//
	// describe('formatDate', () => {});

	describe('transformFromCenter', () => {
		it('should work', () => {
			assert.equal(
				transformFromCenter(10, 10, 20, 20, 2),
				'translate(-30, -30) scale(2)'
			);
			assert.equal(
				transformFromCenter(10, 10, 12, 16, 3),
				'translate(-26, -38) scale(3)'
			);
		});
	});

	describe('extractFields', () => {
		it('should have a similar format to stackByFields', () => {
			const data = [
				{ a: 1, b: 2, c: 3, d: 4 },
				{ a: 4, b: 3, c: 2, d: 1 },
				{ a: 10, b: 15, c: 20, d: 100 },
			];

			assert.deepEqual(extractFields(data, ['a', 'b', 'c', 'd']), [
				[
					[0, 1],
					[0, 2],
					[0, 3],
					[0, 4],
				],
				[
					[0, 4],
					[0, 3],
					[0, 2],
					[0, 1],
				],
				[
					[0, 10],
					[0, 15],
					[0, 20],
					[0, 100],
				],
			]);
		});

		it('should handle missing data points', () => {
			const data = [
				{ a: 1, c: 3, d: 4 },
				{ a: 4, b: 3, c: 2, d: 1 },
				{ a: 10, d: 100 },
			];

			assert.deepEqual(extractFields(data, ['a', 'b', 'c', 'd']), [
				[
					[0, 1],
					[0, 0],
					[0, 3],
					[0, 4],
				],
				[
					[0, 4],
					[0, 3],
					[0, 2],
					[0, 1],
				],
				[
					[0, 10],
					[0, 0],
					[0, 0],
					[0, 100],
				],
			]);
		});
		it('should use minimum domain value', () => {
			const data = [{ y: 1 }, { y: 10 }, { y: 100 }];

			assert.deepEqual(extractFields(data, ['y'], 1), [
				[[1, 1]],
				[[1, 10]],
				[[1, 100]],
			]);
		});
	});

	describe('stackByFields', () => {
		it('should stack data by fields', () => {
			const data = [
				{ a: 1, b: 2, c: 3, d: 4 },
				{ a: 4, b: 3, c: 2, d: 1 },
				{ a: 10, b: 15, c: 20, d: 100 },
			];

			assert.deepEqual(stackByFields(data, ['a', 'b', 'c', 'd']), [
				[
					[0, 1],
					[1, 3],
					[3, 6],
					[6, 10],
				],
				[
					[0, 4],
					[4, 7],
					[7, 9],
					[9, 10],
				],
				[
					[0, 10],
					[10, 25],
					[25, 45],
					[45, 145],
				],
			]);
		});

		it('should handle missing data points', () => {
			const data = [
				{ a: 1, c: 3, d: 4 },
				{ a: 4, b: 3, c: 2, d: 1 },
				{ a: 10, d: 100 },
			];

			assert.deepEqual(stackByFields(data, ['a', 'b', 'c', 'd']), [
				[
					[0, 1],
					[1, 1],
					[1, 4],
					[4, 8],
				],
				[
					[0, 4],
					[4, 7],
					[7, 9],
					[9, 10],
				],
				[
					[0, 10],
					[10, 10],
					[10, 10],
					[10, 110],
				],
			]);
		});
	});

	describe('nearest', () => {
		it('should work with a range of inputs', () => {
			assert.equal(nearest([0, 10, 20, 50], 12.3), 10);
			assert.equal(nearest([0, 10, 20, 50], 15.1), 20);
			assert.equal(nearest([0, 10, 20, 50], 49), 50);
			assert.equal(nearest([0, 10, 20, 50], 49), 50);
		});

		it('should handle numbers smaller than the range', () => {
			assert.equal(nearest([5, 15], -15), 5);
		});

		it('should handle numbers larger than the range', () => {
			assert.equal(nearest([5, 15], -15), 5);
		});

		it('should should favor the left side', () => {
			assert.equal(nearest([0, 10], 5), 0);
		});
	});

	describe('groupByFields', () => {
		it('should work', () => {
			const data = [
				{ a: 'one', b: 20, c: 30, d: 40 },
				{ a: 'two', b: 21, c: 31, d: 41 },
				{ a: 'two', b: 22, c: 32, d: 42 },
			];

			assert.deepEqual(groupByFields(data, ['b', 'c', 'd']), [
				[20, 21, 22],
				[30, 31, 32],
				[40, 41, 42],
			]);
		});

		it('should handle missing and extra data points', () => {
			const data = [
				{ a: 'one', b: 20, c: 30, d: 40 },
				{ a: 'two', b: 21, d: 41 },
				{ a: 'two', b: 22, c: 32, d: 42, e: 100 },
			];

			assert.deepEqual(groupByFields(data, ['b', 'c', 'd']), [
				[20, 21, 22],
				[30, undefined, 32],
				[40, 41, 42],
			]);
		});

		it('should handle non-array fields', () => {
			const data = [
				{ a: 'one', b: 1 },
				{ a: 'two', b: 3 },
				{ a: 'two', b: 10 },
			];

			assert.deepEqual(groupByFields(data, 'b'), [[1, 3, 10]]);
		});
	});

	describe('maxByFieldsStacked', () => {
		it('should return the max for a collection', () => {
			const data = [
				{ a: 'one', b: 1, c: 3, d: 5 },
				{ a: 'two', b: 3, c: 4, d: 7 },
				{ a: 'two', b: 10, c: 10, d: 10 },
			];

			assert.equal(maxByFieldsStacked(data, ['b', 'c', 'd']), 30);
		});
	});

	describe('discreteTicks', () => {
		it('should work on a myriad of ranges', () => {
			assert.deepEqual(discreteTicks(_.times(100), 1), [0]);
			assert.deepEqual(discreteTicks(_.times(100), 2), [0, 99]);
			assert.deepEqual(discreteTicks(_.times(100), 3), [0, 50, 99]);
			assert.deepEqual(discreteTicks(_.times(100), 4), [0, 33, 66, 99]);
		});

		it('should return the plain array if count is too big', () => {
			assert.deepEqual(discreteTicks([1, 2, 3], 3), [1, 2, 3]);
			assert.deepEqual(discreteTicks([1, 2, 3], 4), [1, 2, 3]);
		});

		it('should handle empty arrays', () => {
			assert.deepEqual(discreteTicks([], 100), []);
		});

		it('should handle no count', () => {
			assert.deepEqual(discreteTicks([1, 2, 3]), [1, 2, 3]);
			assert.deepEqual(discreteTicks([1, 2, 3]), [1, 2, 3]);
		});
	});

	describe('byFields', () => {
		it('should work with a single field', () => {
			const data = [{ rev: 1 }, { rev: 2 }, { rev: 'foo', extra: 2 }];

			assert.deepEqual(
				byFields(data, 'rev'),
				[1, 2, 'foo'],
				'got the wrong value back byFields'
			);
		});

		it('should work with a single field in an array', () => {
			const data = [{ rev: 1 }, { rev: 2 }, { rev: 'foo', extra: 2 }];

			assert.deepEqual(
				byFields(data, ['rev']),
				[1, 2, 'foo'],
				'got the wrong value back byFields'
			);
		});

		it('should work with multiple fields', () => {
			const data = [
				{ rev: 1, imps: 100 },
				{ rev: 2, imps: 200 },
				{ rev: 'foo', extra: 2, imps: 300 },
			];

			assert.deepEqual(
				byFields(data, ['rev', 'imps']),
				[1, 2, 'foo', 100, 200, 300],
				'got the wrong value back byFields'
			);
		});
	});

	describe('minByFields', () => {
		it('should take a single field and return the minimum', () => {
			const data = [
				{ a: 1 },
				{ a: 3 },
				{ a: 10 },
				{ a: 3 },
				{ a: 2 },
				{ a: 1 },
			];

			assert.equal(
				minByFields(data, 'a'),
				1,
				'did not get the correct min back'
			);
		});

		it('should take an array of fields and return the minimum', () => {
			const data = [
				{ a: 1, b: 10 },
				{ a: 3 },
				{ a: 10, b: 0 },
				{ a: 3, b: 1 },
				{ a: 2, b: 0 },
				{ a: 1, b: 10 },
			];

			assert.equal(
				minByFields(data, ['a', 'b']),
				0,
				'did not get the correct min back'
			);
		});
	});

	describe('maxByFields', () => {
		it('should take a single field and return the maximum', () => {
			const data = [
				{ foo: 1 },
				{ foo: 3 },
				{ foo: 10 },
				{ foo: 3 },
				{ foo: 2000 },
				{ foo: 1 },
			];

			assert.equal(
				maxByFields(data, 'foo'),
				2000,
				'did not get the correct max back'
			);
		});

		it('should take a single field in an array and return the maximum', () => {
			const data = [
				{ foo: 1 },
				{ foo: 3 },
				{ foo: 10 },
				{ foo: 3 },
				{ foo: 3000 },
				{ foo: 1 },
			];

			assert.equal(
				maxByFields(data, ['foo']),
				3000,
				'did not get the correct max back'
			);
		});

		it('should take an array of fields and return the maximum', () => {
			const data = [
				{ a: 1, b: 10 },
				{ a: 3, b: 20 },
				{ a: 10, b: 0 },
				{ a: 3, b: 1 },
				{ a: 2, b: 0 },
				{ a: 1 },
			];

			assert.equal(
				maxByFields(data, ['a', 'b']),
				20,
				'did not get the correct max back'
			);
		});
	});
});