test: type check the test tree and fix fixture drift

.github/workflows/types.yml

@@ -0,0 +1,31 @@
+name: Type Check
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [22.x]
+        # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'npm'
+      - name: Install dependencies
+        run: npm ci
+      - name: Check types
+        run: npm run check-types

.husky/pre-push

@@ -1,13 +1,13 @@
 #!/usr/bin/env sh
 
-echo "Running pre-push: lint + format checks"
+echo "Running pre-push: lint + format + type checks"
 
 if ! command -v npm >/dev/null 2>&1; then
 	echo "npm not found in PATH. Install Node.js/npm before pushing." >&2
 	exit 1
 fi
 
-if ! npm run check-lint || ! npm run check-format; then
+if ! npm run check-lint || ! npm run check-format || ! npm run check-types; then
 	echo "Pre-push checks failed. Push aborted." >&2
 	exit 1
 fi

AGENTS.md

@@ -47,8 +47,8 @@ Local installs configure Husky hooks automatically.
 
 ## Common tasks
 
-CI check: `npm run prtasks` (lint, format, api:update, tests).
-Repo-wide lint checks: `npm run check-lint` and `npm run check-format`.
+CI check: `npm run prtasks` (lint, format, types, api:update, tests).
+Repo-wide checks: `npm run check-lint`, `npm run check-format` and `npm run check-types`.
 Integration tests: `npm run test-integration` (requires local mint, see below).
 Consumer smoke tests: `npm run test:consumer`.
 Other scripts: see `package.json`.
@@ -98,6 +98,7 @@ DEV=1 make nutshell-stable-down
 ## Linting and TypeScript rules
 
 - Lint config lives in `eslint.config.js` (flat config).
+- `npm run check-types` type checks the test tree (and, via its imports, `src/`). Vitest strips types without checking them, so this is the only thing that catches fixtures drifting from the library types.
 - `any` is not allowed (prefer explicit types, generics, or `unknown` with narrowing).
 - Type-only imports/exports are required (`@typescript-eslint/consistent-type-imports`).
 - No Node-only modules in library code (`import/no-nodejs-modules`).
@@ -111,7 +112,7 @@ Hooks are installed by Husky:
 
 - `commit-msg` enforces Conventional Commits.
 - `pre-commit` runs `lint-staged` on staged files.
-- `pre-push` runs `npm run check-lint` and `npm run check-format`.
+- `pre-push` runs `npm run check-lint`, `npm run check-format` and `npm run check-types`.
 
 ## If you are making changes (author flow)
 

CONTRIBUTING.md

@@ -31,7 +31,7 @@ Husky hooks install automatically during local `npm ci` / `npm install` via the
 
 - `commit-msg` enforces Conventional Commits.
 - `pre-commit` runs `lint-staged` on staged files. For `*.{js,ts}` it runs ESLint with `--fix` and Prettier; for `*.{json,md,yml,yaml}` it runs Prettier.
-- `pre-push` runs repository-wide `npm run check-lint` and `npm run check-format`.
+- `pre-push` runs repository-wide `npm run check-lint`, `npm run check-format` and `npm run check-types`.
 
 If you want more detail on the hook behavior, see the `Hooks` section in `DEVELOPER.md`.
 
@@ -58,7 +58,7 @@ We also have an "all-in-one" script that runs all CI tasks sequentially:
 npm run prtasks
 ```
 
-Tip: if you want to mirror the pre-push checks manually, run `npm run check-lint` and `npm run check-format`.
+Tip: if you want to mirror the pre-push checks manually, run `npm run check-lint`, `npm run check-format` and `npm run check-types`.
 
 ## API Extractor
 

package.json

@@ -41,12 +41,13 @@
     "check-lint": "eslint '**/*.{js,ts}'",
     "format": "prettier --write .",
     "check-format": "prettier --check .",
+    "check-types": "tsc -p test/tsconfig.json",
     "typedoc": "typedoc",
     "api:check": "npm run compile && api-extractor run",
     "api:update": "npm run compile && api-extractor run --local",
     "setup-hooks": "chmod +x scripts/install-git-hooks.sh && ./scripts/install-git-hooks.sh",
     "uninstall-hooks": "git config --local --unset core.hooksPath && [ \"${REMOVE_GITHOOKS:-0}\" = \"1\" ] && rm -rf .githooks || echo 'To remove the installed hooks set REMOVE_GITHOOKS=1'",
-    "prtasks": "npm run lint && npm run format && npm run api:update && npm run test && git status",
+    "prtasks": "npm run lint && npm run format && npm run check-types && npm run api:update && npm run test && git status",
     "prepare": "husky && [ \"$CI\" != \"true\" ] && npm run setup-git || true",
     "setup-git": "git config commit.template .gitmessage",
     "migrate-hooks": "REMOVE_GITHOOKS=1 npm run uninstall-hooks && npm install",

test/bytes.test.ts

@@ -323,7 +323,7 @@ describe('Bytes utility class', () => {
     test('large arrays produce valid base64 on the btoa fallback path (no Buffer)', () => {
       // Force the chunked btoa path that browsers use; harmless where Buffer
       // is already absent.
-      const g = globalThis as typeof globalThis & { Buffer?: unknown };
+      const g = globalThis as unknown as { Buffer?: unknown };
       const originalBuffer = g.Buffer;
       try {
         g.Buffer = undefined;

test/model/Errors.test.ts

@@ -43,7 +43,8 @@ describe('CTSError', () => {
   test('cause is writable and reassignable', () => {
     const err = new CTSError('boom', { cause: new Error('first') });
     const replacement = new Error('second');
-    err.cause = replacement;
+    // `cause` is declared readonly but defined as writable at runtime.
+    (err as { cause?: unknown }).cause = replacement;
     expect(err.cause).toBe(replacement);
   });
 

test/model/MintInfo.test.ts

@@ -704,7 +704,14 @@ describe('MintInfo method/unit capability checks', () => {
 
 describe('MintInfo list caps', () => {
   function spyLogger() {
-    return { error: vi.fn(), warn: vi.fn(), info: vi.fn(), debug: vi.fn(), trace: vi.fn() };
+    return {
+      error: vi.fn(),
+      warn: vi.fn(),
+      info: vi.fn(),
+      debug: vi.fn(),
+      trace: vi.fn(),
+      log: vi.fn(),
+    };
   }
 
   it('truncates an oversized NUT-04 method list and warns', () => {

test/transport/request.node.test.ts

@@ -210,7 +210,7 @@ describe('requests', { timeout: 7500 }, () => {
     const thrown = await request({ endpoint }).catch((e) => e);
     expect(thrown).toBeInstanceOf(HttpResponseError);
     expect(thrown).toMatchObject({ message: 'bad response', status: 200 });
-    expect(thrown.cause).toMatchObject({ message: 'Empty response body' });
+    expect((thrown as HttpResponseError).cause).toMatchObject({ message: 'Empty response body' });
   });
 
   test('maps malformed success JSON to bad response and logs parsing failure', async () => {
@@ -235,7 +235,7 @@ describe('requests', { timeout: 7500 }, () => {
       const thrown = await request({ endpoint }).catch((e) => e);
       expect(thrown).toBeInstanceOf(HttpResponseError);
       expect(thrown).toMatchObject({ message: 'bad response' });
-      expect(thrown.cause).toBeInstanceOf(Error);
+      expect((thrown as HttpResponseError).cause).toBeInstanceOf(Error);
       expect(logger.error).toHaveBeenCalledWith(
         'Failed to parse HTTP response',
         expect.objectContaining({ err: expect.any(Error) }),
@@ -257,7 +257,7 @@ describe('requests', { timeout: 7500 }, () => {
       const thrown = await request({ endpoint }).catch((e) => e);
       expect(thrown).toBeInstanceOf(NetworkError);
       expect(thrown).toMatchObject({ message: 'aborted by runtime' });
-      expect(thrown.cause).toBe(abortError);
+      expect((thrown as NetworkError).cause).toBe(abortError);
     } finally {
       fetchMock.mockRestore();
     }
@@ -279,7 +279,7 @@ describe('requests', { timeout: 7500 }, () => {
       const thrown = await request({ endpoint }).catch((e) => e);
       expect(thrown).toBeInstanceOf(HttpResponseError);
       expect(thrown).toMatchObject({ message: 'bad response', status: 503 });
-      expect(thrown.cause).toBe(bodyReadError);
+      expect((thrown as HttpResponseError).cause).toBe(bodyReadError);
     } finally {
       fetchMock.mockRestore();
     }
@@ -992,9 +992,7 @@ describe('response body read timeout', () => {
 
   test('requestTimeout covers a hung success body that ignores the signal', async () => {
     hungBody(200);
-    const thrown = await request({ endpoint, requestTimeout: 100, idempotent: false }).catch(
-      (e) => e,
-    );
+    const thrown = await request({ endpoint, requestTimeout: 100 }).catch((e) => e);
     expect(thrown).toBeInstanceOf(NetworkError);
     expect((thrown as Error).message).toContain('Request timed out after 100ms');
   }, 2000);
@@ -1010,9 +1008,7 @@ describe('response body read timeout', () => {
 
   test('timeout during a hung error body maps to NetworkError, not a 5xx', async () => {
     hungBody(500);
-    const thrown = await request({ endpoint, requestTimeout: 100, idempotent: false }).catch(
-      (e) => e,
-    );
+    const thrown = await request({ endpoint, requestTimeout: 100 }).catch((e) => e);
     expect(thrown).toBeInstanceOf(NetworkError);
     expect((thrown as Error).message).toContain('Request timed out after 100ms');
   }, 2000);

test/tsconfig.json

@@ -1,6 +1,19 @@
 {
   // Gives eslint's typed rules (projectService) a project covering test/ —
-  // the root tsconfig only includes src/. Not used by builds or vitest.
+  // the root tsconfig only includes src/. Also drives `npm run check-types`,
+  // which type checks test/ and, via its imports, src/. Not used by builds
+  // or vitest (vitest strips types without checking them).
   "extends": "../tsconfig.json",
-  "include": ["**/*"]
+  "compilerOptions": {
+    // Tests import from ../src, so the project root sits above test/.
+    "rootDir": "..",
+    "noEmit": true,
+    "declaration": false,
+    "emitDeclarationOnly": false
+  },
+  "include": ["**/*"],
+  // Consumer smoke harnesses import the built package by its published name, so
+  // they only resolve after a build. They have their own workflow (consumers.yml)
+  // and eslint skips them for the same reason.
+  "exclude": ["consumer/**"]
 }

test/wallet/WalletOps.test.ts

@@ -254,7 +254,6 @@ const meltOnchainMulti: MeltQuoteOnchainResponse = {
 const mintOnchain: MintQuoteOnchainResponse = {
   quote: 'mq-onchain',
   request: 'bc1qdeposit',
-  amount: Amount.from(8),
   unit: 'sat',
   expiry: null,
   pubkey: '0200000',

test/wallet/_setup.ts

@@ -1,6 +1,6 @@
 import { WebSocket } from 'mock-socket';
 import { HttpResponse, http } from 'msw';
-import { setupServer, type SetupServerApi } from 'msw/node';
+import { setupServer, type SetupServer } from 'msw/node';
 import { beforeAll, beforeEach, afterAll, afterEach } from 'vitest';
 
 import { Mint, ConsoleLogger, injectWebSocketImpl } from '../../src';
@@ -27,7 +27,7 @@ export const token3sat =
   'cashuBo2FtdWh0dHA6Ly9sb2NhbGhvc3Q6MzMzOGF1Y3NhdGF0gaJhaUgAvQM1Wd4n0GFwgqNhYQFhc3hAZTdjMWI3NmQxYjMxZTJiY2EyYjIyOWQxNjBiZGY2MDQ2ZjMzYmM0NTcwMjIyMzA0YjY1MTEwZDkyNmY3YWY4OWFjWCEDic2fT5iOOAp5idTUiKfJHFJ3-5MEfnoswe2OM5a4VP-jYWECYXN4QGRlNTVjMTVmYWVmZGVkN2Y5Yzk5OWMzZDRjNjJmODFiMGM2ZmUyMWE3NTJmZGVmZjZiMDg0Y2YyZGYyZjVjZjNhY1ghAt5AxZ2QODuIU8zzpLIIZKyDunWPzj2VnbuJNhAC6M5H';
 export const logger = new ConsoleLogger('debug');
 
-export function setupDefaultHandlers(server: SetupServerApi) {
+export function setupDefaultHandlers(server: SetupServer) {
   server.use(
     http.get(mintUrl + '/v1/info', () => {
       return HttpResponse.json(mintInfoResp);

test/wallet/wallet-melt.node.test.ts

@@ -895,7 +895,7 @@ describe('async melt preference body', () => {
     const debug = vi.fn();
     const wallet = new Wallet(mint, {
       unit,
-      logger: { error: vi.fn(), warn: vi.fn(), info: vi.fn(), debug, trace: vi.fn() },
+      logger: { error: vi.fn(), warn: vi.fn(), info: vi.fn(), debug, trace: vi.fn(), log: vi.fn() },
     });
     await wallet.loadMint();
     const meltTxn = await wallet.prepareMelt('bolt11', meltQuote, proofs);

test/wallet/wallet-mint.node.test.ts

@@ -1383,7 +1383,6 @@ describe('generic mint/melt methods', () => {
           amount: null,
           amount_paid: Amount.from(0),
           amount_issued: Amount.from(0),
-          state: MintQuoteState.UNPAID,
           expiry: null,
           pubkey: '02a1',
         },
@@ -1641,7 +1640,6 @@ describe('generic mint/melt methods', () => {
         unit: 'sat',
         amount: Amount.from(5),
         pubkey: '02f01fd65b16d80f7eff6ef2e0b3c5a8028b745796bbdc06cb503022262b2ebb51',
-        state: MintQuoteState.PAID,
         expiry: null,
         amount_paid: Amount.from(5),
         amount_issued: Amount.from(3),

test/wallet/wallet-quotes-mutants.node.test.ts

@@ -64,7 +64,14 @@ describe('constructor mutants', () => {
     // failIf logs its context before throwing, so the value must not appear there.
     const mnemonic = 'abandon abandon abandon abandon about';
     const error = vi.fn();
-    const logger = { error, warn: vi.fn(), info: vi.fn(), debug: vi.fn(), trace: vi.fn() };
+    const logger = {
+      error,
+      warn: vi.fn(),
+      info: vi.fn(),
+      debug: vi.fn(),
+      trace: vi.fn(),
+      log: vi.fn(),
+    };
 
     expect(() => new Wallet(mint, { unit, logger, bip39seed: mnemonic as never })).toThrow();
 
@@ -1019,7 +1026,7 @@ describe('createLockedMintQuote mutants', () => {
     await wallet.loadMint();
 
     const quote = await wallet.createLockedMintQuote(100, PUBKEY);
-    expect(quote.pubkey.toLowerCase()).toBe(PUBKEY);
+    expect(quote.pubkey!.toLowerCase()).toBe(PUBKEY);
   });
 
   test('rejects a missing pubkey with a clear error, not a TypeError', async () => {
@@ -1120,7 +1127,7 @@ describe('mintProofsBolt11 mutants', () => {
     // A wrong-unit quote object must be rejected by validateMintQuote. A mutant that always
     // takes the string-id branch would skip validation and fail later with a different error.
     await expect(
-      wallet.mintProofsBolt11(1, { quote: 'x', unit: 'usd' } as MintQuoteBolt11Response, []),
+      wallet.mintProofsBolt11(1, { quote: 'x', unit: 'usd' } as MintQuoteBolt11Response),
     ).rejects.toThrow("Quote unit 'usd' does not match wallet unit 'sat'");
   });
 });

test/wallet/wallet-send.node.test.ts

@@ -1088,7 +1088,14 @@ describe('send', () => {
     // Two wallets on one shared source: the documented multi-wallet pattern.
     const counterSource = createEphemeralCounterSource();
     const warn = vi.fn();
-    const spyLogger = { error: vi.fn(), warn, info: vi.fn(), debug: vi.fn(), trace: vi.fn() };
+    const spyLogger = {
+      error: vi.fn(),
+      warn,
+      info: vi.fn(),
+      debug: vi.fn(),
+      trace: vi.fn(),
+      log: vi.fn(),
+    };
     const autoWallet = new Wallet(mint, { unit, bip39seed: seed, counterSource });
     const manualWallet = new Wallet(mint, {
       unit,
@@ -1161,7 +1168,7 @@ describe('send', () => {
       unit,
       bip39seed: seed,
       counterSource: legacySource,
-      logger: { error: vi.fn(), warn, info: vi.fn(), debug: vi.fn(), trace: vi.fn() },
+      logger: { error: vi.fn(), warn, info: vi.fn(), debug: vi.fn(), trace: vi.fn(), log: vi.fn() },
     });
     await wallet.loadMint();