repo-source-code-test-frameworks

Writing Framework Tests

Tests for frameworks/<fw>/. For packages/core/ or packages/methods/, use repo-source-code-test-packages.

Rules

1. React is the canonical reference. New shared tests land in frameworks/react first, then port.
2. Cross-framework consistency. Shared API (useForm/createForm, useField, useFieldArray, Form, Field, FieldArray) keeps the same describe/test names, schemas, initialInput, expected outputs. Only mechanical adapters differ.
3. No framework hint in test names. Never 'should ... (Solid-only)'. Use a // ... comment above the test if framework-specific reasoning matters.
4. No tautological assertions. A test must be able to fail under a real source change.
5. 100% coverage on non-excluded files. Match React's vitest.config.ts exclusions: src/types, src/vitest, **/index.ts(x), test files.
6. vi.waitFor for async, never setTimeout(0).

File layout

frameworks/<fw>/
├── vitest.config.ts          # framework plugin + jsdom + setupFiles + coverage exclusions
├── package.json              # `test: vitest run --typecheck`, framework testing-library devDep
└── src/
    ├── vitest/
    │   ├── setup.ts          # jest-dom + cleanup
    │   ├── renderHook.ts     # (Vue/Svelte only)
    │   └── *Host.svelte      # (Svelte only) shared hosts
    ├── hooks|primitives|composables|runes/<name>/<name>.test.{ts,tsx} + .test-d.ts
    └── components/<Name>/<Name>.test.{ts,tsx}
                            └── *Host.test.svelte # (Svelte only) per-test hosts

Standard test set

Identical describe/test names across all frameworks:

The store stability describe in React tests useMemo across re-renders and is React-only. In other frameworks omit it with a one-line // Note: ... comment.

Per-framework adapters

renderHook

• Preact / React: from the testing library — { result: { current }, rerender, unmount }.
• Solid: from @solidjs/testing-library — { result, owner, cleanup }. result is direct, not wrapped in .current. Use createRoot from solid-js only if no JSX context is needed; our primitives need an owner so renderHook is the default.
• Vue: custom helper at src/vitest/renderHook.ts — mounts a defineComponent({ setup() { return hook(); } }) (the canonical Vue Test Utils TestComponent recipe). Required because onBeforeMount/computed need component context.
• Svelte: custom helper at src/vitest/renderHook.ts — mounts Hook.svelte. Required because onMount and [createAttachmentKey()] need template context. For pure rune logic with no lifecycle, $effect.root(() => { ... })() in a .test.svelte.ts is lighter — but no covered rune in this repo qualifies.

Async

// ❌ flaky
await new Promise((r) => setTimeout(r, 0));
// ✅
await vi.waitFor(() => expect(form.isValid).toBe(false));

For Svelte rune updates, flushSync() from svelte synchronously drains derived/effect updates before the assertion. For Vue, flushPromises() from @vue/test-utils is fine for one-shot microtask drains; prefer vi.waitFor for multi-tick reactive flows.

Type tests (*.test-d.ts)

import * as v from 'valibot';
import { describe, expectTypeOf, test } from 'vitest';
import type { FieldStore } from '../../types/index.ts';
import { useForm } from '../useForm/index.ts';
import { useField } from './useField.ts';

describe('useField', () => {
  test('should narrow input type for primitive leaves', () => {
    const schema = v.object({ name: v.string() });
    const form = useForm({ schema });
    expectTypeOf(useField(form, { path: ['name'] }).input).toEqualTypeOf<
      string | undefined
    >();
  });

  test('should reject invalid paths', () => {
    const form = useForm({ schema: v.object({ name: v.string() }) });
    // @ts-expect-error nonexistent field
    useField(form, { path: ['nonexistent'] });
  });
});

For Preact, wrap leaf types in ReadonlySignal<...> — that's the only framework-specific delta in .test-d.ts files.

Schema types

Always derive with typeof schema. If the schema is referenced only at the type level (host owns runtime), suppress the lint warning rather than hand-writing the valibot generic shape:

// eslint-disable-next-line @typescript-eslint/no-unused-vars -- referenced only via `typeof schema`
const schema = v.object({ name: v.string() });
type Schema = typeof schema;

Framework gotchas

Preact — every reactive field.* / form.* is a ReadonlySignal<T>; read with .value. Setter is field.onInput(v). DOM events fire on oninput. props.autofocus is lowercase.

Solid — primitive is createForm (not useForm). Methods (insert, swap) don't need act(). Use class= not className= in JSX. vite-plugin-solid ≥ 2.8.2 auto-configures vitest; don't add manual deps overrides.

Vue — field.props has no onInput; wire DOM input via the setter:

h('input', {
  ...field.props,
  value: field.input ?? '',
  onInput: (e: Event) => {
    field.input = (e.target as HTMLInputElement).value;
  },
});

For "element removed" assertions, mount with attachTo: document.body and query document.querySelector — wrapper.find keeps finding stale nodes after unmount().

Svelte — runes need Svelte compilation. Three test patterns:

• Hook.svelte via renderHook — default; required when source calls onMount or uses [createAttachmentKey()].
• *Host.test.svelte per-test components — for snippet/slot rendering of Field/FieldArray/Form.
• $effect.root in a *.test.svelte.ts — only for pure rune logic with no lifecycle.

Snippets can't run statements; forward values via {@const _ = onField(field)} with a comment explaining the pattern. After every test, cleanup() from @testing-library/svelte must run in setup.ts or screen.getByTestId finds duplicates.

Svelte build hygiene — package.json files excludes **/*.test.*, **/*.test-d.*, dist/vitest. Verify after adding new fixtures:

pnpm -C frameworks/svelte build && cd frameworks/svelte && pnpm pack --pack-destination /tmp/
tar -tzf /tmp/formisch-svelte-*.tgz | grep -E "(test|Host|vitest)"  # must be empty

Coverage

cd frameworks/<fw> && pnpm exec vitest run --coverage

Must hit 100% on every non-excluded file. Common gaps that need framework-specific tests (no React analogue): field.props.onChange handler (Preact/Solid/Svelte/Vue, covered by validate:'change' test), usePathSignal length-mismatch branch (Preact), unwrap (Solid/Svelte). Add such tests with a // ... comment, not a (X-only) suffix.

Running

pnpm -C frameworks/<fw> test           # runtime + type
pnpm -C frameworks/<fw> lint           # eslint + tsc --noEmit

CI: <fw>_vitest job in .github/workflows/ci.yml.

Checklist

• Test names match React canonical names exactly (no (X-only) suffixes)
• Framework divergence justified by // ... comment, not test name
• vi.waitFor for async, never setTimeout(0)
• Schema types via typeof schema, never hand-written valibot generics
• No tautological assertions
• 100% coverage on covered files
• pnpm test and pnpm lint pass
• (Svelte) pnpm pack output contains no test/Host/vitest files
• CI has a <fw>_vitest job