# Mock Generator

> Design of the ejected Redocly `mock` client generator. Read it, and update it, before changing generators/mock/.

- Skill: `redocly/mock-generator` (Agent Skill)
- Install (CLI): `npx skillmds@latest add redocly/mock-generator`
- Raw SKILL.md: https://api.skillmd.com/api/skills/redocly/mock-generator/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: redocly (https://skillmd.com/u/redocly)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/redocly/mock-generator

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# The `mock` generator — its skill

This file is the DESIGN of your ejected `mock` generator (`generators/mock/`):
**to change the generator, edit this skill first, then make the code match it** — a diff
to `generators/mock/` that has no covering sentence here is incomplete.

## What it emits

A standalone MSW module: `create<Name>()` data factories, `<op>Handler()` /
`<op>ErrorHandler(status, body?)` request handlers, and a `handlers` array.

## Design decisions that must hold

- **Two data modes:** `mockData: static` bakes deterministic samples from the schema
  (examples/defaults first); `faker` emits `faker.*` calls with a seed (`mockSeed`) so
  runs are reproducible.
- **Interpolated identifiers are gated** (`codeIdent`): an operation name or method
  reaching a code position is validated, never trusted, even though the pipeline
  sanitizes upstream.
- Handlers are opt-in overrides: `<op>ErrorHandler` is NOT in `handlers`.
- The module references the sdk's TYPES only — never its runtime.

## The stage files

`render.ts` assembles the module (factories, handlers, the `handlers` array);
`sample.ts` bakes deterministic sample values from the schema, `values.ts` renders the
data trees, and `faker.ts` emits the faker-mode expressions. `index.ts` is the entry.

## Ejecting it

`redocly eject-generator mock` copies this generator's TypeScript source folder to
`generators/mock/`, exactly as we wrote it, importing `@redocly/client-generator`,
`@redocly/client-generator/printers/typescript`, and `@redocly/openapi-core`. Running a
`.ts` generator uses Node's type stripping (Node 22.18, 23.6, or newer); newer built-in
versions merge in per file with `--update`. Change the data strategy, the handler shape,
or the factory surface, and regenerate.

## The modify loop

1. Edit this skill: state the new behavior or decision.
2. Make `generators/mock/` match it.
3. Run `redocly generate-client` and inspect the `git diff` of the generated output —
   generated files are never hand-edited.

Newer built-in versions merge in with `redocly eject-generator mock --update`.