Examples

Self-contained TypeScript examples, each highlighting a storymock feature. Run any example with npx tsx examples/<file>.ts.

Fakers & Composability

Core domains, semantic domains, constraint chaining, composability, batch generation.

Highlights:

• numeric(), text(), temporal(), bool(), choice(), collection()
• Constraint chaining: .min(), .max(), .float(), .precision(), .length()
• Format methods that change return type: .hex(), .iso()
• Faker-in-faker composability: temporal().year(numeric().min(2020).max(2025))
• Batch (.create(5)) and unique (.unique().create(3))
• .nullable() and .optional()

import { numeric, text, person, temporal, choice } from 'storymock';

const id    = text().uuid().create();                     // '550e8400-e29b-...'
const age   = person().age().min(18).max(65).create();    // 34
const price = numeric().min(1).max(999).precision(2).create(); // 42.99
const date  = temporal().year(numeric().min(2020).max(2025)).create(); // Date
const roles = choice('viewer', 'editor', 'admin').unique().create(3);

Try it

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Traits & Customization

Named states, combining traits, inline overrides, immutable forking.

Highlights:

• Defining traits with .trait('name', { ... })
• Applying one trait: .with('completed')
• Combining traits left-to-right: .with('urgent', 'completed')
• Inline overrides: .with({ title: 'Fix bug #123' })
• Traits + overrides: .with('urgent', { assignee: 'Alice' })
• Immutable forking: base schema unchanged after .with()

import { schema, text, lorem, person, choice, collection } from 'storymock';

const TaskSchema = schema<Task>({
  id: text().uuid(),
  title: lorem().sentence(),
  priority: choice('low', 'medium', 'high'),
  assignee: person().fullName(),
}).trait('urgent', { priority: 'high' as const });

TaskSchema.with('urgent').create();
TaskSchema.with('urgent', { assignee: 'Alice' }).create();

Try it

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Conditional Fields

when() for conditional logic, derive() for computed fields, dependency resolution.

Highlights:

• when() with string keys: when('type', { percentage: ..., fixed: ... })
• when() with numeric keys and _ default
• when() with boolean keys
• derive() computing from resolved siblings
• derive() returning a faker instead of a literal
• Field resolution order (DAG)

import { schema, choice, numeric, derive, when } from 'storymock';

const CouponSchema = schema<Coupon>({
  type: choice('percentage', 'fixed'),
  value: when('type', {
    percentage: numeric().min(5).max(100),
    fixed: numeric().min(10).max(500).precision(2),
  }),
  label: derive(({ type, value }) =>
    type === 'percentage' ? `${value}% OFF` : `$${value} OFF`
  ),
});

Try it

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Story Composition

ref() for foreign keys, .setup() for wiring, addMany, type accumulation.

Highlights:

• story().add() and .addMany() with type accumulation
• ref('entry') resolving foreign keys via .id()
• ref('entry', 'field') referencing a specific field
• ref() on addMany entries resolving to an array of IDs
• .setup() for complex relationship wiring
• Inline overrides with ref()

import { story, ref } from 'storymock';

const blogStory = story()
  .add('author', AuthorSchema)
  .addMany('posts', PostSchema, 3, { authorId: ref('author') })
  .add('comment', CommentSchema, { authorId: ref('author') })
  .setup((m) => { m.comment.postId = m.posts[0].id; });

const { author, posts, comment } = blogStory.create();
// comment.authorId === author.id ✓

Try it

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Story Inheritance

Base stories, extending, setup accumulation, cascading .with(), targeting.

Highlights:

• Base story → extended story with additional entries
• .setup() accumulation across inheritance
• Cascading .with() across multiple entries
• Targeting specific addMany items: .with('teams[0]', { ... })
• Forking independent variants from the same base
• Reusable wiring functions

const orgBase = story()
  .add('org', OrgSchema)
  .addMany('teams', TeamSchema, 2, { orgId: ref('org') });

const orgWithMembers = orgBase
  .addMany('members', MemberSchema, 4)
  .setup(wireTeamMembers);

// Fork independent variants
const proOrg = orgWithMembers.with('org', { plan: 'pro' as const });
const deletedOrg = orgWithMembers.with('org', 'deleted');

Try it

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Seeding & Determinism

.seed() at every level, configure({ seed }), reproducible snapshots.

Highlights:

• Faker seed: numeric().seed(42).create()
• Schema seed: UserSchema.seed(42).create()
• Story seed: myStory.seed(42).create()
• Seed precedence (faker > schema > story > global)
• Global seed via configure({ seed: 42 })
• Deterministic test assertions

import { numeric, schema, configure } from 'storymock';

// Same seed → same value, every time
const a = numeric().min(1).max(100).seed(42).create();
const b = numeric().min(1).max(100).seed(42).create();
// a === b ✓

// Schema-level seed for full objects
const user1 = UserSchema.seed(42).create();
const user2 = UserSchema.seed(42).create();
// user1.id === user2.id ✓

Try it

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Running Examples

git clone https://github.com/storymock/storymock.git
cd storymock
pnpm install

npx tsx examples/file.ts

Contributing an Example

Examples highlight features, not business scenarios. See the Contributing guide for the full checklist.