YRest Language Support

VS Code extension for yrest — the zero-config YAML-based REST API mock server.

Provides syntax highlighting, diagnostics and autocompletion for db.yml and *.yrest.yml files.

Features

Syntax highlighting

Highlights yrest-specific constructs on top of standard YAML:

Injections are also active in plain .yaml files and inside TypeScript/JavaScript (e.g. test setup files using yrest).

Diagnostics

Validates on every save and keystroke:

• YAML syntax errors — with exact position from the yaml parser
• _rel entity names must match a root collection in the same file
• Relation targets (shorthand string or _target) must match a root collection
• _type must be many2one, one2one, many2many (or aliases m2o, o2o, m2m)
• _car-direct / _car-inverse must use 0..1, 1..1, 1..n or 0..n
• DSL strings are validated against the full compact format regex

Supported files

The extension activates automatically for:

For any other filename, add to your VS Code settings:

"files.associations": { "mock.yml": "yrest" }

Syntax quick reference

Shorthand relation (level 1)

_rel:
  posts:
    userId: users

Compact DSL (level 2 — type + cardinality)

_rel:
  posts:
    userId: "m2o:users[1..1->0..n]"
    tags: "m2m:tags@post_tags(postId,tagId)[0..n->0..n]+nested"

Verbose form (full control)

_rel:
  payments:
    bookingId:
      _type: many2one
      _target: bookings
      _foreignKey: bookingId
      _car-direct: 1..1
      _car-inverse: 0..n
      _nested: true

Custom routes with scenarios and template variables

_routes:
  - method: POST
    path: /auth/login
    scenarios:
      - when:
          body.role: admin
        response:
          status: 200
          body:
            token: "{{uuid}}"
            generatedAt: "{{now}}"
    otherwise:
      status: 401
      body: { error: Invalid credentials }
    delay: 300

  - method: GET
    path: /orders/:id/receipt
    response:
      status: 200
      body:
        orderId: "{{params.id}}"
        issuedAt: "{{now}}"

Requirements

• VS Code ^1.90.0
• A db.yml file or any *.yrest.yml file following the yrest YAML format

No additional runtime dependencies are needed. The extension bundles its own yaml parser.

Roadmap

License

MIT — aggiovato