feat: Add SHA-256 utility

src/hashing.test.ts

@@ -0,0 +1,65 @@
+import * as nobleHashes from '@noble/hashes/sha256';
+import { webcrypto } from 'crypto';
+import { parse } from 'semver';
+
+import { bytesToHex, stringToBytes } from './bytes';
+import { sha256 } from './hashing';
+
+describe('sha256', () => {
+  const isNode18 = parse(process.version)?.major === 18;
+
+  // The global does not exist in Node 18, so we must add it.
+  // eslint-disable-next-line jest/no-if
+  if (isNode18) {
+    Object.defineProperty(globalThis, 'crypto', {
+      value: webcrypto,
+      writable: true,
+    });
+  }
+
+  it('returns a digest for a byte array', async () => {
+    const digest = await sha256(stringToBytes('foo bar'));
+    expect(bytesToHex(digest)).toBe(
+      '0xfbc1a9f858ea9e177916964bd88c3d37b91a1e84412765e29950777f265c4b75',
+    );
+  });
+
+  it('returns a digest for a larger byte array', async () => {
+    const digest = await sha256(new Uint8Array(1024).fill(1));
+    expect(bytesToHex(digest)).toBe(
+      '0x5a648d8015900d89664e00e125df179636301a2d8fa191c1aa2bd9358ea53a69',
+    );
+  });
+
+  it('falls back to noble when digest function is unavailable', async () => {
+    const nobleSpy = jest.spyOn(nobleHashes, 'sha256');
+
+    Object.defineProperty(globalThis.crypto.subtle, 'digest', {
+      value: undefined,
+      writable: true,
+    });
+
+    const digest = await sha256(stringToBytes('foo bar'));
+    expect(bytesToHex(digest)).toBe(
+      '0xfbc1a9f858ea9e177916964bd88c3d37b91a1e84412765e29950777f265c4b75',
+    );
+
+    expect(nobleSpy).toHaveBeenCalled();
+  });
+
+  it('falls back to noble when subtle APIs are unavailable', async () => {
+    const nobleSpy = jest.spyOn(nobleHashes, 'sha256');
+
+    Object.defineProperty(globalThis.crypto, 'subtle', {
+      value: undefined,
+      writable: true,
+    });
+
+    const digest = await sha256(stringToBytes('foo bar'));
+    expect(bytesToHex(digest)).toBe(
+      '0xfbc1a9f858ea9e177916964bd88c3d37b91a1e84412765e29950777f265c4b75',
+    );
+
+    expect(nobleSpy).toHaveBeenCalled();
+  });
+});

src/hashing.ts

@@ -0,0 +1,25 @@
+import { sha256 as nobleSha256 } from '@noble/hashes/sha256';
+
+/**
+ * Compute a SHA-256 digest for a given byte array.
+ *
+ * Uses the native crypto implementation and falls back to noble.
+ *
+ * @param bytes - A byte array.
+ * @returns The SHA-256 hash as a byte array.
+ */
+export async function sha256(bytes: Uint8Array): Promise<Uint8Array> {
+  // Use crypto.subtle.digest whenever possible as it is faster.
+  if (
+    'crypto' in globalThis &&
+    typeof globalThis.crypto === 'object' &&
+    // eslint-disable-next-line no-restricted-globals
+    globalThis.crypto.subtle?.digest
+  ) {
+    // eslint-disable-next-line no-restricted-globals
+    return new Uint8Array(
+      await globalThis.crypto.subtle.digest('SHA-256', bytes),
+    );
+  }
+  return nobleSha256(bytes);
+}

src/index.test.ts

@@ -152,6 +152,7 @@ describe('index', () => {
         "parseCaipChainId",
         "remove0x",
         "satisfiesVersionRange",
+        "sha256",
         "signedBigIntToBytes",
         "stringToBytes",
         "timeSince",

src/index.ts

@@ -7,6 +7,7 @@ export * from './coercers';
 export * from './collections';
 export * from './encryption-types';
 export * from './errors';
+export * from './hashing';
 export type { Hex } from './hex';
 export {
   HexStruct,

src/node.test.ts

@@ -159,6 +159,7 @@ describe('node', () => {
         "readJsonFile",
         "remove0x",
         "satisfiesVersionRange",
+        "sha256",
         "signedBigIntToBytes",
         "stringToBytes",
         "timeSince",