IMPORTANT: This module is an improvement from joyent/node-assert-plus module with added assertions registration methods.

Installation:

npm install assert-enhanced

For types definitions:

npm install AshLePoney/node-assert-enhanced-types --save-dev

Example:

const assert = require('assert-enhanced');

function example (stdout, chunk, next) {
  assert.writable(stdout, 'stdout');
  assert.object(chunk, 'chunk');
  assert.string(chunk.id, 'chunk.id');
  assert.buffer(chunk.buffer, 'chunk.buffer');
  assert.func(next, 'next');

  // ...

  stdout.write(chunk);
}

Or to add a new assertion set

const assert = require('assert-enhanced');

const definition = {
  custom: {
    check: (arg) => (arg instanceof Custom),
    operator: 'instanceof',
    actual: (arg) => Object.prototype.toString.call(arg).slice(8, -1)
  }
};

assert.register(null, definitions, { arrayOf: false, optionalArrayOf: false });

// Register to assert-enhanced:
// assert.custom
// assert.optionalCustom
// assert.arrayOfCustom         (generation disabled by options).
// assert.optionalArrayOfCustom (generation disabled by options).

API:

The added assertions methods take two arguments, the value tested first and then the name of the checked parameter.

assert.bool(myBoolArg, 'myBoolArg');
assert.optionalBool(myBoolArg, 'myBoolArg');
assert.arrayOfbool(myBoolArg, 'myBoolArg');
assert.optionalArrayOfBool(myBoolArg, 'myBoolArg');

On bad assertion it will throw an EnhancedAssertionError:

AssertionError [ERR_ASSERTION]: myBoolArg (bool) is required.
    at Object.<anonymous> (/home/user/projects/test-assert-enhanced/test.js:3:8)
    at Module._compile (internal/modules/cjs/loader.js:1147:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1167:10)
    at Module.load (internal/modules/cjs/loader.js:996:32)
    at Function.Module._load (internal/modules/cjs/loader.js:896:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
    at internal/main/run_main_module.js:17:47

Enhanced:

• assert.EnhancedAssertionError
• assert.bool
• assert.number
• assert.string
• assert.symbol
• assert.object
• assert.func
• assert.array
• assert.asyncFunc
• assert.promise
• assert.date
• assert.regexp
• assert.buffer
• assert.stream
• assert.readable
• assert.writable
• assert.duplex
• assert.optionalBool
• assert.optionalNumber
• assert.optionalString
• assert.optionalSymbol
• assert.optionalObject
• assert.optionalFunc
• assert.optionalArray
• assert.optionalAsyncFunction
• assert.optionalPromise
• assert.optionalDate
• assert.optionalRegexp
• assert.optionalBuffer
• assert.optionalStream
• assert.optionalReadable
• assert.optionalWritable
• assert.optionalDuplex
• assert.arrayOfBool
• assert.arrayOfNumber
• assert.arrayOfString
• assert.arrayOfSymbol
• assert.arrayOfObject
• assert.arrayOfFunc
• assert.arrayOfArray
• assert.arrayOfAsyncFunc
• assert.arrayOfPromise
• assert.arrayOfDate
• assert.arrayOfRegexp
• assert.arrayOfBuffer
• assert.arrayOfStream
• assert.arrayOfReadable
• assert.arrayOfWritable
• assert.arrayOfDuplex
• assert.optionalArrayOfBool
• assert.optionalArrayOfNumber
• assert.optionalArrayOfString
• assert.optionalArrayOfSymbol
• assert.optionalArrayOfObject
• assert.optionalArrayOfFunc
• assert.optionalArrayOfArray
• assert.optionalArrayOfAsyncFunc
• assert.optionalArrayOfPromise
• assert.optionalArrayOfDate
• assert.optionalArrayOfRegexp
• assert.optionalArrayOfBuffer
• assert.optionalArrayOfStream
• assert.optionalArrayOfReadable
• assert.optionalArrayOfWritable
• assert.optionalArrayOfDuplex

Enhanced registration methods:

• assert.register
• assert.registerStandardAssertion
• assert.registerOptionalAssertion
• assert.registerArrayOfAssertion
• assert.registerOptionalArrayOfAssertion
• assert.getClassname
• assert.getTypeof

Node.js assert module:

See more on Node.js assert module: https://nodejs.org/api/assert.html

• assert
• assert.AssertionError
• assert.fail
• assert.ok
• assert.equal (deprecated)
• assert.notEqual (deprecated)
• assert.deepEqual (deprecated)
• assert.notDeepEqual (deprecated)
• assert.strictEqual
• assert.notStrictEqual
• assert.deepStrictEqual
• assert.notDeepStrictEqual
• assert.ifError
• assert.throws (>= v10.0.0)
• assert.rejects (>= v10.0.0)
• assert.doesNotThrow (>= v10.0.0)
• assert.doesNotReject (>= v10.0.0)
• assert.match (>= v13.6.0)
• assert.doesNotMatch (>= v13.6.0)

assert.register(target, definitions, options)->target

Register assertions sets.

| argument | type | details | |-------------|--------------------|-------------| | target | Object or Function | The target where to save the generated assertion methods. If it's null or undefined then registration is processed on the exported module. | | definitions | Object | The definitions object will wrap the definitions of the different assertions that need to be added. | | options | Object (optional) | The options object will store the states to know if we should cancel the generation of methods by types. Any registration type can be disabled using options ({ [type]: false }). |

Example:

const definitions = {
  custom: {
    check: (arg) => (arg instanceof Custom),
    operator: 'instanceof',
    actual: assert.getClassname
  }
};

assert.register(null, definitions, { optionalArrayOf: false });

// Register [standard, optional, arrayOf]

assert.registerStandardAssertion(target, name, definition)->target

Register standard assertion.

| argument | type | details | |--------------|--------------------|-------------| | target | Object or Function | The target where to save the generated assertion methods. If it's null or undefined then registration is processed on the exported module. | | name | String | The assertion method name. | | definition | Object | The definitions object. |

Example:

assert.registerStandardAssert(null, 'custom', {
  check: (arg) => (arg instanceof Custom),
  operator: 'instanceof',
  actual: assert.getClassname
});

assert.registerOptionalAssertion(target, name, definition)->target

Register optional assertion.

| argument | type | details | |--------------|--------------------|-------------| | target | Object or Function | The target where to save the generated assertion methods. If it's null or undefined then registration is processed on the exported module. | | name | String | The assertion method name. | | definition | Object | The definitions object. |

Example:

assert.registerOptionalAssertion(null, 'custom', {
  check: (arg) => (arg instanceof Custom),
  operator: 'instanceof',
  actual: assert.getClassname
});

assert.registerArrayOfAssertion(target, name, definition)->target

Register arrayOf assertion.

| argument | type | details | |--------------|--------------------|-------------| | target | Object or Function | The target where to save the generated assertion methods. If it's null or undefined then registration is processed on the exported module. | | name | String | The assertion method name. | | definition | Object | The definitions object. |

Example:

assert.registerArrayOfAssertion(null, 'custom', {
  check: (arg) => (arg instanceof Custom),
  operator: 'instanceof',
  actual: assert.getClassname
});

assert.registerOptionalArrayOfAssertion(target, name, definition)->target

Register optional arrayOf assertion.

| argument | type | details | |--------------|--------------------|-------------| | target | Object or Function | The target where to save the generated assertion methods. If it's null or undefined then registration is processed on the exported module. | | name | String | The assertion method name. | | definition | Object | The definitions object. |

Example:

assert.registerOptionalArrayOfAssertion(null, 'custom', {
  check: (arg) => (arg instanceof Custom),
  operator: 'instanceof',
  actual: assert.getClassname
});

assert.getClassname(arg)->string

Get an object classname, it's used to seed the actual property from the definitions.

| argument | type | details | |--------------|----------|-------------| | arg | any | |

assert.getTypeof(arg)->string

Get a typeof, it's used to seed the actual property from the definitions.

| argument | type | details | |--------------|----------|-------------| | arg | any | |