dep-perf-analyzer

Measure the runtime performance impact of npm dependencies — startup time, memory, and event loop blocking

Install

npm install dep-perf-analyzer

Usage

import analyzeDep, {analyzeMultiple, formatReport} from 'dep-perf-analyzer';

// Analyze a single dependency
const result = await analyzeDep('express');
console.log(result.startupTime); // Startup time in ms
console.log(result.memoryDelta.heapUsed); // Heap memory delta in bytes

// Analyze multiple dependencies
const results = await analyzeMultiple(['express', 'koa', 'fastify']);
console.log(formatReport(results));

API

analyzeDep(packageName, options?)

Returns: Promise<{startupTime, memoryDelta, eventLoopBlock}>

packageName

Type: string

The package name or module specifier to analyze.

options

Type: object

iterations

Type: number
Default: 3

Number of measurement iterations. Median values are used for stability.

warmup

Type: boolean
Default: true

Whether to run a warmup iteration before measuring.

Return value

• startupTime — Median startup time in milliseconds
• memoryDelta.rss — RSS delta in bytes
• memoryDelta.heapUsed — Used heap delta in bytes
• memoryDelta.heapTotal — Total heap delta in bytes
• eventLoopBlock — Median event loop blocking time in milliseconds

analyzeMultiple(packageNames, options?)

Returns: Promise<Map<string, AnalysisResult>>

Analyze multiple packages sequentially.

formatReport(results)

Returns: string

Format a results map as a human-readable table.

Related

• import-cost — Display import size in your editor

License

MIT