proportionate/test/proportionateArraySpec.js

Convenience methods for dealing with proportions (a part, share, or number considered in comparative relation to a whole).

var chai;
chai = require("chai");
chai.should();


describe("Proportionate arrays", function() {
    it("should index directly on a one-to-one mapping", function() {
        require("../lib").arrays();
        [1, 2, 3].proportionate(0, 3).should.equal(1);
        [1, 2, 3].proportionate(1, 3).should.equal(1);
        [1, 2, 3].proportionate(2, 3).should.equal(2);
        [1, 2, 3].proportionate(3, 3).should.equal(3);
    });
    it("should only index extremes when extremes are met", function() {
        require("../lib/arrays");
        [1, 2, 3].proportionate(0, 6).should.equal(1);
        [1, 2, 3].proportionate(1, 6).should.equal(1);
        [1, 2, 3].proportionate(2, 6).should.equal(1);
        [1, 2, 3].proportionate(3, 6).should.equal(2);
        [1, 2, 3].proportionate(4, 6).should.equal(2);
        [1, 2, 3].proportionate(5, 6).should.equal(3);
        [1, 2, 3].proportionate(6, 6).should.equal(3);
        [1, 2, 3].proportionate(6, 7).should.equal(3);
    });
    it("should skip items when the max is small", function() {
        require("../lib").arrays();
        [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].proportionate(0, 3).should.equal(1);
        [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].proportionate(1, 3).should.equal(3);
        [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].proportionate(2, 3).should.equal(7);
        [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].proportionate(3, 3).should.equal(10);
    });
    it("should clamp to the extremes when out of bounds", function() {
        require("../lib").arrays();
        [1, 2, 3].proportionate(-1, 3).should.equal(1);
        [1, 2, 3].proportionate(4, 3).should.equal(3);
    });
});