[donskov]

Closes #87: the package is now "type": "module" with a single ESM entry (build/index.js), so the import condition no longer points at ESM syntax in a CommonJS-typed .js file. Verified with tsx@4.23.1 from the report.

Stacked on #96 (part 4 of 7 for @peculiar/webcrypto 2.0.0; merge in order).

Packaging only.

• rollup + @rollup/plugin-typescript → tsdown (webcrypto-core's config + platform: "node", SPDX banner kept). Generated declarations replace the hand-written index.d.ts. tslib, rimraf, react-native field and the clear/rebuild scripts are gone.
• tsconfig = pvtsutils + allowed deviations: lib: ["es2023", "DOM"] (typecheck fails without DOM: KeyUsage, JsonWebKey, …), types: ["node"], experimentalDecorators (@JsonProp in src/keys, src/mechs/{aes,des,hmac}). No stripInternal.
• engines >=14.18.0 → ^20.19.0 || >=22.12.0, "type": "module", "sideEffects": false, publishConfig.access: public, files build/, README.md, LICENSE.md.
• Type-only imports (7 lines). Dev dependencies updated (vitest 5.0.5, oxlint 1.90, oxfmt 0.75, tsdown 0.23.2, attw); TypeScript stays on 6.
• @types/node stays on 25 (rule 1 exception). 26 drops the crypto.RsaPublicKey/RsaPrivateKey option types the RSA code uses, and 24 and lower reject the DOM JsonWebKey in createPublicKey({ format: "jwk" }). On 25 the source compiles unchanged.
• Type fix: with plain generated types, crypto.subtle would be core's SubtleCrypto, which only accepts AlgorithmIdentifier. Code that compiles against 1.7.1 (sign({ name: "ECDSA", hash }), encrypt({ name: "AES-GCM", iv }), generateKey(..., usages as const)) would fail. Crypto.subtle is now GenerateKeyPair & SubtleCrypto & globalThis.SubtleCrypto; src/index.spec.ts compiles these calls in npm run typecheck.

Public types vs npm 1.7.1 index.d.ts

1.7.1 (hand-written)	2.0.0 (generated)
class Crypto implements globalThis.Crypto	class Crypto extends core.Crypto (which implements globalThis.Crypto)
subtle: SubtleCrypto (DOM)	subtle: GenerateKeyPair & SubtleCrypto & globalThis.SubtleCrypto; adds providers and core's overloads
getRandomValues<T extends ArrayBufferView | null>(array: T): T	same
randomUUID(): \${string}-…``	same (inherited)
class CryptoKey implements globalThis.CryptoKey (algorithm, extractable, type, usages)	webcrypto-core's CryptoKey (same members, plus static create/isKeyType)

Same two runtime exports. Consumers still need the DOM lib (as with 1.7.1). Consumer call shapes, 1.7.1 vs 2.0.0: all compile in both.

Verification (packed tarball of the full stack, installed with its peers)

Workload: ECDSA P-256 sign/verify, JWK and PKCS8/SPKI round trips, AES-GCM, RSA-PSS, Ed25519, and pkijs 4 setEngine/CryptoEngine with a self-signed certificate sign/parse/verify().

Node.js	require()	import
20.19.0	ok	ok
22.11.0	ERR_REQUIRE_ESM (expected)	ok
22.12.0	ok (ExperimentalWarning)	ok
24.15.0	ok	ok

Dual-package probe:

Check	npm 1.7.1	2.0.0
require(x).Crypto === import(x).Crypto	fail	pass
require(x).CryptoKey === import(x).CryptoKey	fail	pass
webcrypto CryptoKey === core CryptoKey (require / import)	pass / pass	pass / pass
key from require instanceof import / core CryptoKey	fail / fail	pass / pass
import Crypto signs / exports JWK with a require key	fail / fail	pass / pass

sideEffects: false (rolldown 1.2.15, esbuild 0.28.2, webpack 5.112.2, target node):

Entry	false	true
Full workload (incl. AES/HMAC JWK, which needs the @JsonProp registrations)	runs: 170.5 / 173.0 / 172.1 KB	runs: 170.5 / 173.0 / 172.0 KB
CryptoKey only	0.3 KB or less	106–113 KB

TypeScript 6 consumers (skipLibCheck: false, no experimentalDecorators, lib DOM):

Setting	Result
nodenext, node20 (.mts and .cts)	pass
preserve + bundler	pass
node16	.mts pass, .cts TS1479 (documented)
commonjs + node10	needs ignoreDeprecations: "6.0"; then passes with skipLibCheck. With skipLibCheck: false, 2 × TS2307 from webcrypto-core 2's own .d.ts (@peculiar/utils/bytes subpath); core alone reproduces it

release-please dry run on the full stack: finds v1.7.1, proposes chore(release): v2.0.0 with both BREAKING CHANGE notes.

BEGIN_COMMIT_OVERRIDE
build!: ship ESM-only output for Node.js ^20.19.0 || >=22.12.0

BREAKING CHANGE: @peculiar/webcrypto is ESM-only and requires Node.js ^20.19.0 || >=22.12.0 (was >=14.18.0). The bundles build/webcrypto.js (CommonJS) and build/webcrypto.es.js and the hand-written index.d.ts are replaced by unbundled ES modules with build/index.js and build/index.d.ts as the entry point; the react-native field is removed. Deep imports into build/ stay blocked by exports. CommonJS code can still require("@peculiar/webcrypto") on supported Node.js versions through require(esm); Node.js 22.0-22.11 can't. require() and import now load the same module, so CryptoKey instanceof checks and keys work across both. TypeScript projects that compile to CommonJS need "module": "node20" or "nodenext". The exported names (Crypto, CryptoKey) are unchanged; their declarations are now generated, so Crypto shows its webcrypto-core base class. See "Breaking Changes In v2" in the README.
END_COMMIT_OVERRIDE