typemockr

TypeMockr

This repository generates TypeScript mock factories from types.

Configuration

Create a typemockr.json in the root of your project (the project that installs this package) to configure generation. Supported fields:

• include: array of glob paths to input source files (same as before)

• baseDir: array of base directory prefixes to strip when computing output paths

• outDir: output directory for generated mocks

• mappings: optional object that maps faker generator expression strings to arrays of dotted property path patterns. Keys are generator expressions and values are arrays of path patterns (generator -> [patterns]).

• mappingProvider: optional path to a module that exports a mapping provider function (signature: (type, path, context?) => string | undefined | null). Use this when you prefer to keep mapping logic in code or share mappings across projects.

  Examples: Minimal configuration (no mappings):

  {
    "include": ["src/**/*.ts"],
    "baseDir": ["src/"],
    "outDir": "src/$mock"
  }

  Provide mappings inline in typemockr.json (note the expected shape: generator -> patterns):

  {
    "include": ["src/**/*.ts"],
    "baseDir": ["src/"],
    "outDir": "src/$mock",
    "mappings": {
      "*.id": "faker.string.uuid()",
      "*firstName*": "faker.person.firstName()",
      "*.recipientName": "faker.person.fullName()"
    }
  }

  Or use a mappingProvider that points to a JS/TS module (example: mappings/provider.js):

  {
    "include": ["src/**/*.ts"],
    "baseDir": ["src/"],
    "outDir": "src/$mock",
    "mappingProvider": "./mappings/provider.js"
  }

  Example provider:

  // mappings/provider.js
  const mappings = [
    ["*.id", "faker.string.uuid()"],
    ["*firstName*", "faker.person.firstName()"],
    ["*.recipientName", "faker.person.fullName()"],
    ["*", "faker.lorem.word()"],
  ];
  
  function keyToRegExp(key) {
    // escape regex special chars except *
    const escaped = key.replace(/[-/\\^$+?.()|[\]{}]/g, "\\__CODE_BLOCK_3__amp;");
    const regexStr = "^" + escaped.replace(/\*/g, ".*") + "$";
    return new RegExp(regexStr);
  }
  
  module.exports = function mappingProvider(type, path, _context) {
    for (const [key, generator] of mappings) {
      const re = keyToRegExp(key);
      if (re.test(path)) return generator;
    }
  
    return undefined;
  };

  Note: If both mappings and mappingProvider are present, the runtime mappingProvider is consulted first. If it returns a non-null/undefined string for a given property, that value will be used. Inline mappings are used as a fallback when the provider returns undefined/null or is not provided.