Skip to content

Refactor cost calculator into helper helpers #134

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
NessieCanCode merged 1 commit into from
Sep 9, 2025
Merged

Refactor cost calculator into helper helpers #134

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
148 changes: 101 additions & 47 deletions src/cost-calculator.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,84 @@ async function loadRatesConfig() {
}
}

/**
* Normalize a usage record.
*
* @param {Object} record - Raw usage record
* @returns {Object|null} normalized record or null if invalid
*/
function normalizeRecord(record) {
if (!record) {
return null;
}
const account = record.account || 'unknown';
const month = (record.date || '').slice(0, 7); // YYYY-MM
const coreHours =
typeof record.core_hours === 'number' && record.core_hours > 0
? record.core_hours
: 0;
const gpuHours =
typeof record.gpu_hours === 'number' && record.gpu_hours > 0
? record.gpu_hours
: 0;
if (coreHours <= 0 && gpuHours <= 0) {
return null;
}
return { account, month, coreHours, gpuHours };
}

/**
* Apply rates, overrides, and discounts to a normalized record.
*
* @param {Object} record - Normalized record
* @param {Object} ctx - Rate context
* @returns {Object} record with cost
*/
function applyRates(record, ctx) {
const { account, month, coreHours, gpuHours } = record;
const ovr = ctx.overrides[account] || {};
const rate =
typeof ovr.rate === 'number'
? ovr.rate
: typeof ctx.historicalRates[month] === 'number'
? ctx.historicalRates[month]
: ctx.defaultRate;
const gpuRate =
typeof ovr.gpuRate === 'number'
? ovr.gpuRate
: typeof ctx.historicalGpuRates[month] === 'number'
? ctx.historicalGpuRates[month]
: ctx.defaultGpuRate;
const validRate = rate > 0 ? rate : 0;
const validGpuRate = gpuRate > 0 ? gpuRate : 0;
let cost = coreHours * validRate + gpuHours * validGpuRate;
const rawDiscount = typeof ovr.discount === 'number' ? ovr.discount : 0;
const discount = Math.min(1, Math.max(0, rawDiscount));
if (discount > 0) {
cost *= 1 - discount;
}
return { account, month, coreHours, gpuHours, cost };
}

/**
* Accumulate a record's cost into the charges object.
*
* @param {Object} charges - Accumulator
* @param {Object} record - Record with cost
* @returns {Object} updated charges
*/
function accumulateCharge(charges, record) {
const { account, month, coreHours, gpuHours, cost } = record;
if (!charges[month]) charges[month] = {};
if (!charges[month][account]) {
charges[month][account] = { core_hours: 0, gpu_hours: 0, cost: 0 };
}
charges[month][account].core_hours += coreHours;
charges[month][account].gpu_hours += gpuHours;
charges[month][account].cost += cost;
return charges;
}

/**
* Calculate charges from usage records applying rates and overrides.
*
Expand All @@ -45,55 +123,28 @@ function calculateCharges(usage, config) {
if (!config) {
throw new Error('rate configuration required');
}
const defaultRate =
typeof config.defaultRate === 'number' && config.defaultRate > 0
? config.defaultRate
: 0;
const defaultGpuRate =
typeof config.defaultGpuRate === 'number' && config.defaultGpuRate > 0
? config.defaultGpuRate
: 0;
const historical = config.historicalRates || {};
const gpuHistorical = config.historicalGpuRates || {};
const overrides = config.overrides || {};
const ctx = {
defaultRate:
typeof config.defaultRate === 'number' && config.defaultRate > 0
? config.defaultRate
: 0,
defaultGpuRate:
typeof config.defaultGpuRate === 'number' && config.defaultGpuRate > 0
? config.defaultGpuRate
: 0,
historicalRates: config.historicalRates || {},
historicalGpuRates: config.historicalGpuRates || {},
overrides: config.overrides || {},
};

const charges = {};

for (const record of usage) {
if (!record) {
continue;
}
const account = record.account || 'unknown';
const month = (record.date || '').slice(0, 7); // YYYY-MM
const ovr = overrides[account] || {};
const coreHours = typeof record.core_hours === 'number' && record.core_hours > 0 ? record.core_hours : 0;
const gpuHours = typeof record.gpu_hours === 'number' && record.gpu_hours > 0 ? record.gpu_hours : 0;
if (coreHours <= 0 && gpuHours <= 0) {
continue;
}
const rate = typeof ovr.rate === 'number'
? ovr.rate
: (typeof historical[month] === 'number' ? historical[month] : defaultRate);
const gpuRate = typeof ovr.gpuRate === 'number'
? ovr.gpuRate
: (typeof gpuHistorical[month] === 'number' ? gpuHistorical[month] : defaultGpuRate);
const validRate = rate > 0 ? rate : 0;
const validGpuRate = gpuRate > 0 ? gpuRate : 0;
let cost = coreHours * validRate + gpuHours * validGpuRate;
const rawDiscount = typeof ovr.discount === 'number' ? ovr.discount : 0;
const discount = Math.min(1, Math.max(0, rawDiscount));
if (discount > 0) {
cost *= (1 - discount);
}

if (!charges[month]) charges[month] = {};
if (!charges[month][account]) {
charges[month][account] = { core_hours: 0, gpu_hours: 0, cost: 0 };
const charges = usage.reduce((acc, rec) => {
const normalized = normalizeRecord(rec);
if (!normalized) {
return acc;
}
charges[month][account].core_hours += coreHours;
charges[month][account].gpu_hours += gpuHours;
charges[month][account].cost += cost;
}
const costed = applyRates(normalized, ctx);
return accumulateCharge(acc, costed);
}, {});

for (const month of Object.keys(charges)) {
for (const account of Object.keys(charges[month])) {
Expand All @@ -110,4 +161,7 @@ function calculateCharges(usage, config) {
module.exports = {
calculateCharges,
loadRatesConfig,
normalizeRecord,
applyRates,
accumulateCharge,
};
50 changes: 49 additions & 1 deletion test/unit/calculator.test.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,13 @@
const assert = require('assert');
const fs = require('fs');
const path = require('path');
const { calculateCharges, loadRatesConfig } = require('../../src/cost-calculator');
const {
calculateCharges,
loadRatesConfig,
normalizeRecord,
applyRates,
accumulateCharge,
} = require('../../src/cost-calculator');

async function testFileConfig() {
const usage = [
Expand All @@ -19,6 +25,45 @@ async function testFileConfig() {
assert.strictEqual(charges['2024-01'].education.gpu_hours, 10);
}

function testNormalizeRecord() {
const rec = normalizeRecord({
account: 'acct',
date: '2024-03-15',
core_hours: 5,
gpu_hours: 2,
});
assert.deepStrictEqual(rec, {
account: 'acct',
month: '2024-03',
coreHours: 5,
gpuHours: 2,
});
assert.strictEqual(normalizeRecord({ core_hours: -1, gpu_hours: 0 }), null);
}

function testApplyRates() {
const ctx = {
defaultRate: 0.02,
defaultGpuRate: 0.2,
historicalRates: { '2024-03': 0.03 },
historicalGpuRates: { '2024-03': 0.3 },
overrides: { acct: { discount: 0.25 } },
};
const rec = { account: 'acct', month: '2024-03', coreHours: 100, gpuHours: 10 };
const res = applyRates(rec, ctx);
assert.strictEqual(res.cost, (100 * 0.03 + 10 * 0.3) * 0.75);
}

function testAccumulateCharge() {
const charges = {};
const rec = { account: 'acct', month: '2024-03', coreHours: 1, gpuHours: 2, cost: 3 };
accumulateCharge(charges, rec);
accumulateCharge(charges, rec);
assert.deepStrictEqual(charges, {
'2024-03': { acct: { core_hours: 2, gpu_hours: 4, cost: 6 } },
});
}

function testPassedConfig() {
const usage = [
{ account: 'acct', date: '2024-03-01', core_hours: 100, gpu_hours: 10 }
Expand Down Expand Up @@ -103,6 +148,9 @@ function testRoundingTotals() {
}

async function run() {
testNormalizeRecord();
testApplyRates();
testAccumulateCharge();
await testFileConfig();
testPassedConfig();
testInvalidUsageIgnored();
Expand Down
Loading