CodeSampleX

Sample

@babel/core 7.26.0: template

Verified sample for npm @babel/core 7.26.0: template. The contract ran on node 22 · linux debian/x64 · docker and passed: template parses JavaScript code…

sha256:47f09ef30d04d1bf98cdeb4074ef0aa1bde50196d2bab004aa7610c7cef03b21

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment linux 24 · ubuntu · glibc 2.39 x64 npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux debian/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22@sha256:8a34c4ab3ea2…		 2026-09-03

Case

HOW
Goal
verify template in pkg:npm/%40babel/core@7.26.0
Packages
Symbols
  • template
Created
2026-09-03T11:42:46Z

Contract

  1. template parses JavaScript code templates into AST statements with placeholder substitution
  2. template.ast directly parses source strings and tagged template literals into AST nodes
  3. template.expression creates an AST builder specialized for expressions
  4. template.statements parses code into an array of Statement AST nodes

Files

  • PROMPT.md
  • csx.json
  • package-lock.json
  • package.json
  • spec.json
  • src/index.mjs
  • test/contract.mjs

Download the source artifact (tar.gz)

Source

PROMPT.md
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 template in pkg:npm/%40babel/core@7.26.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40babel/core@7.26.0
Demonstrate these symbols/APIs:
  - template

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.
csx.json
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package-lock.json
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  "name": "sample-babel-core-template",
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      "license": "Apache-2.0",
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package.json
{
  "name": "sample-babel-core-template",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "@babel/core": "7.26.0"
  }
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify template in pkg:npm/%40babel/core@7.26.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40babel/core@7.26.0"
  ],
  "symbols": [
    "template"
  ]
}
src/index.mjs
import { template, types } from '@babel/core';

/**
 * Builds a variable declaration AST node from a template string with identifier and value replacements.
 * @param {string} varName - Identifier name for the variable
 * @param {string|number} value - Value to assign
 * @returns {object} AST node representing the variable declaration
 */
export function buildVariableDeclaration(varName, value) {
  const build = template(`const NAME = VALUE;`);
  const valueNode = typeof value === 'number' ? types.numericLiteral(value) : types.stringLiteral(value);
  return build({
    NAME: types.identifier(varName),
    VALUE: valueNode,
  });
}

/**
 * Parses source code directly into an AST node using template.ast.
 * @param {string} code - JavaScript source code
 * @returns {object} AST node
 */
export function parseAst(code) {
  return template.ast(code);
}

/**
 * Creates an expression AST node from a template with placeholder substitution.
 * @param {string} leftId - Identifier on the left
 * @param {number} rightVal - Number on the right
 * @returns {object} BinaryExpression AST node
 */
export function buildBinaryExpression(leftId, rightVal) {
  const buildExpr = template.expression(`LEFT + RIGHT`);
  return buildExpr({
    LEFT: types.identifier(leftId),
    RIGHT: types.numericLiteral(rightVal),
  });
}

/**
 * Parses multiple statements into an array of Statement AST nodes using template.statements.
 * @param {string} code - Code containing statements
 * @returns {object[]} Array of Statement AST nodes
 */
export function parseStatements(code) {
  const buildStmts = template.statements(code);
  return buildStmts();
}

export { template, types };
test/contract.mjs
import assert from 'node:assert/strict';
import {
  template,
  types,
  buildVariableDeclaration,
  parseAst,
  buildBinaryExpression,
  parseStatements,
} from '../src/index.mjs';

// 1. template parses JavaScript code templates into AST statements with placeholder substitution
{
  const decl = buildVariableDeclaration('answer', 42);
  assert.equal(decl.type, 'VariableDeclaration');
  assert.equal(decl.kind, 'const');
  assert.equal(decl.declarations[0].id.name, 'answer');
  assert.equal(decl.declarations[0].init.value, 42);

  const buildRequire = template(`const IMPORT_NAME = require(SOURCE);`);
  const requireAst = buildRequire({
    IMPORT_NAME: types.identifier('myLib'),
    SOURCE: types.stringLiteral('my-lib'),
  });
  assert.equal(requireAst.type, 'VariableDeclaration');
  assert.equal(requireAst.declarations[0].id.name, 'myLib');
  assert.equal(requireAst.declarations[0].init.arguments[0].value, 'my-lib');
}

// 2. template.ast directly parses source strings and tagged template literals into AST nodes
{
  const astFromString = parseAst(`const x = 10;`);
  assert.equal(astFromString.type, 'VariableDeclaration');
  assert.equal(astFromString.declarations[0].id.name, 'x');
  assert.equal(astFromString.declarations[0].init.value, 10);

  const fnAst = template.ast`function ${types.identifier('greet')}(name) { return "hello " + name; }`;
  assert.equal(fnAst.type, 'FunctionDeclaration');
  assert.equal(fnAst.id.name, 'greet');
  assert.equal(fnAst.params[0].name, 'name');
}

// 3. template.expression creates an AST builder specialized for expressions
{
  const exprAst = buildBinaryExpression('counter', 5);
  assert.equal(exprAst.type, 'BinaryExpression');
  assert.equal(exprAst.operator, '+');
  assert.equal(exprAst.left.name, 'counter');
  assert.equal(exprAst.right.value, 5);

  const directExpr = template.expression(`A * B`)({
    A: types.identifier('x'),
    B: types.identifier('y'),
  });
  assert.equal(directExpr.type, 'BinaryExpression');
  assert.equal(directExpr.operator, '*');
  assert.equal(directExpr.left.name, 'x');
  assert.equal(directExpr.right.name, 'y');
}

// 4. template.statements parses code into an array of Statement AST nodes
{
  const stmts = parseStatements(`const a = 1; let b = 2; return a + b;`);
  assert.equal(Array.isArray(stmts), true);
  assert.equal(stmts.length, 3);
  assert.equal(stmts[0].type, 'VariableDeclaration');
  assert.equal(stmts[0].declarations[0].id.name, 'a');
  assert.equal(stmts[1].type, 'VariableDeclaration');
  assert.equal(stmts[1].declarations[0].id.name, 'b');
  assert.equal(stmts[2].type, 'ReturnStatement');
}

console.log('Contract assertions passed.');

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