📦 Trim npm package size (521 KB → 213 KB, no runtime change)

[taras]

Motivation

pkg-size.dev/effection reports the published package at ~580 KB, which looks alarming. On inspection almost all of it is install-only dev artifacts, not code that lands in a consumer's app bundle — the runtime cost a bundler actually pulls in was already optimal at ~5.8 KB min+gzip. The tarball was ~30% sourcemaps, ~20% duplicated .d.ts (emitted into both esm/ and script/), and ~18% raw TS source — none of which a bundler loads. This PR trims that fat without touching the code consumers run.

Approach

Three dnt build options in tasks/build-npm.ts:

Option	Effect
sourceMap: false	stop shipping .js.map (no runtime value)
declaration: "separate"	emit .d.ts once into a shared types/ folder instead of duplicating across esm/ and script/
skipSourceOutput: true	stop shipping raw src/*.ts

Works on the currently pinned dnt 0.41.3 — no toolchain bump required.

Measured (via npm pack)

Metric	Before	After	Δ
unpacked on disk	521 KB	213 KB	−59%
files	427	145	−66%
download (.tgz gzip)	80 KB	40 KB	−49%
runtime bundle (min+gzip)	5.8 KB	5.8 KB	unchanged

Verified

• ✅ ESM import { run, sleep } from "effection" runs
• ✅ CJS require("effection") runs (CJS output preserved)
• ✅ tsc --noEmit resolves types against the new shared types/ folder

Notes / decisions

• deno bundle --declaration (the "bundled single .d.ts" idea) was evaluated and rejected: it can't type-check effection's cross-runtime lib/main.ts (uses Deno.*, DOM, and a node:process dynamic import at once — no single lib satisfies all three), and pre-bundling gave no runtime-size win since bundlers already tree-shake the modular output.
• sourceMap: false is the one debatable line — it drops the biggest chunk (157 KB) but also removes published debugging maps. If shipping sourcemaps is preferred, revert just that line (unpacked lands at ~370 KB instead of 213 KB).

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/effection@1206

commit: fe1198b

[codspeed-hq]

Merging this PR will not alter performance

✅ 6 untouched benchmarks

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_{Comparing bundle-size-experiment (fe1198b) with v4 (56af00f)}