pnpm/benchmarks/README.md

pnpm Benchmarks

Compares pnpm install performance between the current branch and main.

Prerequisites

• hyperfine — install via brew install hyperfine
• The current branch must be compiled (pnpm run compile)
• If providing a pre-existing main checkout path, it must also be compiled

Usage

pnpm run compile
./benchmarks/bench.sh

If a git worktree with main already exists, the script finds and uses it automatically. Otherwise it creates one at ../.pnpm-bench-main (a sibling of the repo), installs dependencies, and compiles.

You can also point to a specific checkout of main:

./benchmarks/bench.sh /path/to/main

Scenarios

#	Name	Lockfile	Store + Cache	Description
1	Headless	✔ frozen	warm	Repeat install with warm store
2	Re-resolution	✔ + add dep	warm	Add a new dependency to an existing lockfile
3	Full resolution	✗	warm	Resolve everything from scratch with warm store and cache
4	Headless cold	✔ frozen	cold	Typical CI install — fetch all packages with lockfile
5	Cold install	✗	cold	True cold start — nothing cached

All scenarios use --ignore-scripts and isolated store/cache directories per variant.

Output

Results are printed to the terminal and saved as:

• results.md — consolidated markdown table
• <scenario>-main.json / <scenario>-branch.json — raw hyperfine data

All files are written to a temp directory printed at the end of the run.

Configuration

Edit the variables at the top of bench.sh:

• WARMUP — number of warmup runs before timing (default: 1)
• RUNS — number of timed runs per benchmark (default: 10)