@types/babel__traverse 7.28.0: traverse

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 traverse in pkg:npm/%40types/babel__traverse@7.28.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40types/babel__traverse@7.28.0
Demonstrate these symbols/APIs:
  - traverse
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:sha256:46efcf46dcd86d5846828e64d97c443bb737a43fff38e90d6a8f15e81e50836e","constraints":{"executionContext":"node"},"contract":["package manifest specifies index.d.ts type declarations and TypeScript version 5.1","declares traverse function overloads accepting parent Node, TraverseOptions, Scope, and state","declares traverse static properties and methods including visitors, verify, explode, and cheap","declares visitors namespace with explode, verify, and merge utilities","declares cache namespace with path and scope WeakMaps and cache clearing functions","declares TraverseOptions type alias combining Scope options and Visitor mapping","declares Scope and NodePath class declarations"],"goal":"verify traverse in pkg:npm/%40types/babel__traverse@7.28.0","kind":"HOW","packages":["pkg:npm/%40types/babel__traverse@7.28.0"],"schemaVersion":1,"symbols":["traverse"]},"contractCommand":["node","test/contract.mjs"],"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/%40types/babel__traverse@7.28.0"],"schemaVersion":1,"subject":"pkg:npm/%40types/babel__traverse@7.28.0","symbols":["traverse"],"verifierAdapter":"node-typescript@1"}

{
  "name": "test-babel-traverse",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "test-babel-traverse",
      "version": "1.0.0",
      "license": "ISC",
      "dependencies": {
        "@types/babel__traverse": "^7.28.0"
      }
    },
    "node_modules/@babel/helper-string-parser": {
      "version": "7.29.7",
      "resolved": "https://registry.npmjs.org/@babel/helper-string-parser/-/helper-string-parser-7.29.7.tgz",
      "integrity": "sha512-Pb5ijPrZ89GDH8223L4UP8i6QApWxs04RbPQJTeWDV0/keR2E36MeKnyr6LYmUUvqRRI+Iv87SuF1W6ErINzYw==",
      "license": "MIT",
      "engines": {
        "node": ">=6.9.0"
      }
    },
    "node_modules/@babel/helper-validator-identifier": {
      "version": "7.29.7",
      "resolved": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-7.29.7.tgz",
      "integrity": "sha512-qehxGkRj55h/ff8EMaJ+cYhyaKlHIxqYDn682wQD7RNp9UujOQsHog2uS0r2vzr4pW+sXf90NeeayjcNaX3fFg==",
      "license": "MIT",
      "engines": {
        "node": ">=6.9.0"
      }
    },
    "node_modules/@babel/types": {
      "version": "7.29.8",
      "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.29.8.tgz",
      "integrity": "sha512-Vj1jF3cPfxg7OAfoI7QnVKLoILlm2JF9pnVHrX8qx7AHMiYWT+NDAA7jChlNgRS4WTLc/fD1lXLmPixluj+3Gg==",
      "license": "MIT",
      "dependencies": {
        "@babel/helper-string-parser": "^7.29.7",
        "@babel/helper-validator-identifier": "^7.29.7"
      },
      "engines": {
        "node": ">=6.9.0"
      }
    },
    "node_modules/@types/babel__traverse": {
      "version": "7.28.0",
      "resolved": "https://registry.npmjs.org/@types/babel__traverse/-/babel__traverse-7.28.0.tgz",
      "integrity": "sha512-8PvcXf70gTDZBgt9ptxJ8elBeBjcLOAcOtoO/mPJjtji1+CdGbHgm77om1GrsPxsiE+uXIpNSK64UYaIwQXd4Q==",
      "license": "MIT",
      "dependencies": {
        "@babel/types": "^7.28.2"
      }
    }
  }
}

{
  "name": "test-babel-traverse",
  "version": "1.0.0",
  "license": "ISC",
  "type": "module",
  "dependencies": {
    "@types/babel__traverse": "^7.28.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify traverse in pkg:npm/%40types/babel__traverse@7.28.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40types/babel__traverse@7.28.0"
  ],
  "symbols": [
    "traverse"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';
import fs from 'node:fs';
import path from 'node:path';

const require = createRequire(import.meta.url);

// 1. Resolve @types/babel__traverse package manifest and verify type declaration entry points
const pkgPath = require.resolve('@types/babel__traverse/package.json');
const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf8'));

assert.equal(pkg.name, '@types/babel__traverse', 'Package name must be @types/babel__traverse');
assert.equal(pkg.version, '7.28.0', 'Package version must be 7.28.0');
assert.equal(pkg.types, 'index.d.ts', 'Package types entry must point to index.d.ts');
assert.equal(pkg.typeScriptVersion, '5.1', 'TypeScript version must be 5.1');
assert.ok(pkg.dependencies && pkg.dependencies['@babel/types'], 'Must declare dependency on @babel/types');

const typesDir = path.dirname(pkgPath);
const dtsContent = fs.readFileSync(path.join(typesDir, 'index.d.ts'), 'utf8');

// 2. Verify traverse main function declaration and default export
assert.ok(
  dtsContent.includes('declare const traverse: {'),
  'traverse constant declaration must be present'
);
assert.ok(
  dtsContent.includes('<S>(parent: Node, opts: TraverseOptions<S>, scope: Scope | undefined, state: S, parentPath?: NodePath): void;') &&
  dtsContent.includes('(parent: Node, opts?: TraverseOptions, scope?: Scope, state?: any, parentPath?: NodePath): void;'),
  'traverse function overloads must accept Node, TraverseOptions, Scope, state, and NodePath'
);
assert.ok(
  dtsContent.includes('export default traverse;'),
  'Default export traverse must be present'
);

// 3. Verify traverse static properties and methods
assert.ok(
  dtsContent.includes('visitors: typeof visitors;') &&
  dtsContent.includes('verify: typeof visitors.verify;') &&
  dtsContent.includes('explode: typeof visitors.explode;') &&
  dtsContent.includes('cheap: (node: Node, enter: (node: Node) => void) => void;') &&
  dtsContent.includes('clearNode: (node: Node, opts?: RemovePropertiesOptions) => void;') &&
  dtsContent.includes('removeProperties: (tree: Node, opts?: RemovePropertiesOptions) => Node;') &&
  dtsContent.includes('hasType: (tree: Node, type: Node["type"], denylistTypes?: string[]) => boolean;') &&
  dtsContent.includes('cache: typeof cache;'),
  'traverse must declare visitors, verify, explode, cheap, clearNode, removeProperties, hasType, and cache properties'
);

// 4. Verify visitors namespace utilities
assert.ok(
  dtsContent.includes('export namespace visitors {') &&
  dtsContent.includes('function explode<S = unknown>(') &&
  dtsContent.includes('function verify(visitor: Visitor): void;') &&
  dtsContent.includes('function merge<State>(visitors: Array<Visitor<State>>): Visitor<State>;'),
  'visitors namespace must declare explode, verify, and merge functions'
);

// 5. Verify cache namespace and TraverseOptions type definition
assert.ok(
  dtsContent.includes('export namespace cache {') &&
  dtsContent.includes('let path: WeakMap<t.Node, Map<t.Node, NodePath>>;') &&
  dtsContent.includes('let scope: WeakMap<t.Node, Scope>;') &&
  dtsContent.includes('function clear(): void;') &&
  dtsContent.includes('function clearPath(): void;') &&
  dtsContent.includes('function clearScope(): void;'),
  'cache namespace must declare path, scope WeakMaps and cache clearing functions'
);
assert.ok(
  dtsContent.includes('export type TraverseOptions<S = Node> = {') &&
  dtsContent.includes('scope?: Scope;') &&
  dtsContent.includes('noScope?: boolean;') &&
  dtsContent.includes('denylist?: NodeType[];') &&
  dtsContent.includes('shouldSkip?: (node: NodePath) => boolean;'),
  'TraverseOptions type alias must declare scope, noScope, denylist, and shouldSkip properties'
);

// 6. Verify Scope and NodePath class declarations
assert.ok(
  dtsContent.includes('export class Scope {') &&
  dtsContent.includes('constructor(path: NodePath, parentScope?: Scope);') &&
  dtsContent.includes('traverse<S>(node: Node | Node[], opts: TraverseOptions<S>, state: S): void;') &&
  dtsContent.includes('generateUidIdentifier(name?: string): t.Identifier;'),
  'Scope class declaration must declare constructor, traverse, and identifier generator methods'
);
assert.ok(
  dtsContent.includes('export class NodePath<T = Node>') &&
  dtsContent.includes('export class Binding {'),
  'NodePath and Binding classes must be exported'
);

console.log('Contract tests passed successfully.');