rations

Ration things within a given policy using timestamps

Installation

npm install rations

Usage

Simply describe your policies and check an array of timestamps. The .check() function will return an error object if any of the policies are met.

This module doesn't do anything fancy; it just counts the number of timestamps within bounds.

    var test = require("tape");
    var Ration = require("rations");
 
    test("Should limit within policy", function(assert) {
            var ration = new Ration([{
                label: "Only ten things per day",
                count: 10,
                period: ms.days(1)
            }, {
                label: "Only three things per hour",
                count: 3,
                period: ms.hours(1),
            }, {
                label: "Only one thing per minute",
                count: 1,
                period: ms.minutes(1)
            }]);
        
            var cases = [{
                label: "Assorted timestamps within bounds yield no err",
                err: undefined,
                stamps: [
                    Date.now() - ms.days(1),
                    Date.now() - ms.days(2),
                    Date.now() - ms.days(3),
                    Date.now() - ms.minutes(1),
                    Date.now() - ms.minutes(2),
                    Date.now() - ms.hours(1),
                ],
            },
            {
                label: "Exceeds the hourly limit",
                err: "Only three things per hour",
                stamps: [
                    Date.now() - ms.minutes(1),
                    Date.now() - ms.minutes(2),
                    Date.now() - ms.minutes(3),
                    Date.now() - ms.minutes(4),
                ],
            }
            // more cases in the tests...
            ];
        
            cases.forEach(function(testCase) {
                var err = ration.check(testCase.stamps);
        
                if (testCase.err) {
                    assert.ok(err instanceof Error, "err isa Error");
                    assert.equal(err.message, testCase.err, testCase.label);
                    return;
                }
                assert.ok(!err, testCase.label);
        
            });
            assert.end();
        });