type-check 0.4.0: parseType

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify type-check.parseType in pkg:npm/type-check@0.4.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/type-check@0.4.0
Demonstrate these symbols/APIs:
  - type-check.parseType

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:296e6f9d11e98bf24240191321a55a8ca89df0928e37028f8cbe66691a409114","contract":["assert parseType parses primitive types (Number, String, Boolean) into type AST nodes","assert parseType parses union types into multiple alternative type AST nodes","assert parseType parses array structures '[Type]' and tuple structures '(Type1, Type2)'","assert parseType parses object field records '{key: Type}' into fields structure AST nodes","assert parseType throws an error on invalid type syntax"],"goal":"verify type-check.parseType in pkg:npm/type-check@0.4.0","kind":"HOW","packages":["pkg:npm/type-check@0.4.0"],"schemaVersion":1,"symbols":["type-check.parseType"]},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/type-check@0.4.0"],"schemaVersion":1,"subject":"pkg:npm/type-check@0.4.0","symbols":["type-check.parseType"],"verifierAdapter":"node-typescript@1"}

const { parseType } = require('type-check');

module.exports = {
  parseType,
};

{
  "name": "sample-300142138",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-300142138",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "type-check": "0.4.0"
      }
    },
    "node_modules/prelude-ls": {
      "version": "1.2.1",
      "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.2.1.tgz",
      "integrity": "sha512-vkcDPrRZo1QZLbn5RLGPpg/WmIQ65qoWWhcGKf/b5eplkkarX0m9z8ppCat4mlOqUsWpyNuYgO3VRyrYHSzX5g==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8.0"
      }
    },
    "node_modules/type-check": {
      "version": "0.4.0",
      "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.4.0.tgz",
      "integrity": "sha512-XleUoc9uwGXqjWwXaUTZAmzMcFZ5858QA2vvx1Ur5xIcixXIP+8LnFDgRplU30us6teqdlskFfu+ae4K79Ooew==",
      "license": "MIT",
      "dependencies": {
        "prelude-ls": "^1.2.1"
      },
      "engines": {
        "node": ">= 0.8.0"
      }
    }
  }
}

{
  "name": "sample-300142138",
  "version": "1.0.0",
  "description": "verify type-check.parseType in pkg:npm/type-check@0.4.0",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "license": "MIT-0",
  "dependencies": {
    "type-check": "0.4.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify type-check.parseType in pkg:npm/type-check@0.4.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/type-check@0.4.0"
  ],
  "symbols": [
    "type-check.parseType"
  ]
}

const assert = require('node:assert');
const { parseType } = require('type-check');

// 1. Parse primitive types
const numAst = parseType('Number');
assert.deepStrictEqual(numAst, [{ type: 'Number' }], 'Number type expression should parse to Number AST');

const strAst = parseType('String');
assert.deepStrictEqual(strAst, [{ type: 'String' }], 'String type expression should parse to String AST');

const boolAst = parseType('Boolean');
assert.deepStrictEqual(boolAst, [{ type: 'Boolean' }], 'Boolean type expression should parse to Boolean AST');

// 2. Parse union types
const unionAst = parseType('Number | String');
assert.deepStrictEqual(unionAst, [{ type: 'Number' }, { type: 'String' }], 'Union type expression should parse to multiple alternative AST nodes');

// 3. Parse array and tuple structures
const arrayAst = parseType('[Number]');
assert.deepStrictEqual(arrayAst, [
  {
    structure: 'array',
    of: [{ type: 'Number' }],
  },
], 'Array type expression should parse to array structure AST');

const tupleAst = parseType('(String, Number)');
assert.deepStrictEqual(tupleAst, [
  {
    structure: 'tuple',
    of: [[{ type: 'String' }], [{ type: 'Number' }]],
  },
], 'Tuple type expression should parse to tuple structure AST');

// 4. Parse object field records
const fieldsAst = parseType('{a: Number, b: String}');
assert.deepStrictEqual(fieldsAst, [
  {
    structure: 'fields',
    of: {
      a: [{ type: 'Number' }],
      b: [{ type: 'String' }],
    },
    subset: false,
  },
], 'Object record type expression should parse to fields structure AST');

// 5. Throws on unexpected character or malformed syntax
assert.throws(
  () => parseType('!'),
  /Unexpected character/,
  'Invalid type expression syntax should throw an Error'
);

console.log('All contract assertions for parseType passed successfully.');