@shapeshift-labs/frontier-fixtures

Deterministic fixture and scenario generation for Frontier apps.

frontier-fixtures turns a seed plus schema/collection/scenario declarations into replayable app fixtures: schema-shaped state, related entity collections, actor sessions, route states, Frontier patch streams, event records, JSONL bundles, hashes, and compact evidence summaries.

It is deliberately not a general fake-data package. The root import stays small and dependency-light so generated scenarios can feed unit tests, docs, component previews, browser evidence runs, benchmark fixtures, and bug repros from the same manifest.

Install

npm install @shapeshift-labs/frontier-fixtures

Example

import {
  compileFixtureScenario,
  generateFixtureState,
  verifyFixtureScenarioRun
} from '@shapeshift-labs/frontier-fixtures';

const fixture = generateFixtureState({
  seed: 'billing-demo-v1',
  collections: {
    users: {
      count: 3,
      typename: 'User',
      schema: {
        type: 'object',
        required: ['id', 'name'],
        properties: {
          id: { type: 'string' },
          name: { type: 'string' }
        }
      }
    },
    invoices: {
      count: 8,
      typename: 'Invoice',
      schema: {
        type: 'object',
        required: ['id', 'title', 'status'],
        properties: {
          id: { type: 'string' },
          title: { type: 'string' },
          status: { enum: ['draft', 'open', 'paid'] },
          notes: { type: 'array', minItems: 0, maxItems: 0, items: { type: 'object' } }
        }
      },
      relations: {
        userId: { collection: 'users', field: 'id' }
      }
    }
  }
});

const run = compileFixtureScenario({
  id: 'billing.overdue-resolution',
  initialState: fixture.state,
  actors: [{ id: 'account-manager', role: 'finance' }],
  steps: [
    { actorId: 'account-manager', kind: 'set', path: '/invoices/2/status', value: 'overdue' },
    { actorId: 'account-manager', kind: 'route', route: '/billing/invoices/2' },
    { actorId: 'account-manager', kind: 'append', path: '/invoices/2/notes', value: { body: 'Customer called' } },
    { actorId: 'account-manager', kind: 'assign', path: '/invoices/2', value: { status: 'paid' } }
  ],
  diffOptions: { arrayKey: 'id' }
});

console.log(run.patches);
console.log(verifyFixtureScenarioRun(run).ok);

Surface

• createFixtureRng creates deterministic seedable RNGs with forked streams for stable fixture subgraphs.
• generateFixtureValue emits JSON values from a small JSON Schema-compatible subset.
• generateFixtureState builds root state plus related entity collections and records collection summaries.
• compileFixtureScenario runs route/action/event/state steps and emits replay-verified Frontier patches.
• createFixturePatchStream, verifyFixturePatchStream, and verifyFixtureScenarioRun make patch correctness machine-checkable.
• encodeFixtureJsonl, decodeFixtureJsonl, hashFixtureValue, and stableFixtureStringify support evidence bundles and reproducible assertions.

Boundary

The root package depends only on @shapeshift-labs/frontier. It emits structural route records, event records, actors, and evidence summaries without importing frontier-route, frontier-event-log, frontier-test, frontier-playwright, frontier-schema, or app frameworks.

Schema, route, event-log, test, browser, and app-framework integrations should be adapters around the generated records, not dependencies of this root package.

Source Repository

Package source is published at siliconjungle/-shapeshift-labs-frontier-fixtures.

Determinism And Privacy

Fixture output is seeded and reproducible. Generated strings use synthetic values such as Fixture 123 and example.invalid email addresses; the package does not generate real-looking personal data by default.

Every scenario compile verifies each step patch by applying it back to the previous state. verifyFixtureScenarioRun replays the full patch stream from initialState to finalState.

Benchmarks

Run the package-local benchmark:

npm run bench

The package benchmark writes benchmarks/results/frontier-fixtures-package-bench-latest.json when run from the package directory. Frontier-only package measurements cover schema value generation, related collection generation, scenario compilation, patch replay verification, patch stream generation, hashing, and JSONL encoding/decoding.

These are Frontier-only package measurements, not competitor comparisons.