HM-DEF Usage

hm-def-usage.spec.js

import R from 'ramda';
import HMD from 'hm-def';
import $ from 'sanctuary-def';
import F from 'fluture';
import { env, create as createS } from 'sanctuary';
import { env as flutureEnv } from 'fluture-sanctuary-types';

const funcName = R.concat ('func-sandbox/');

const docsLink = R.concat ('http://trsdln.com/func-sandbox#');

const Model = modelName => (typesStrMap) => {
  const modelRecord = $.RecordType (typesStrMap);
  return $.NullaryType (
    funcName (modelName),
    docsLink (modelName),
    $.test ([]) (modelRecord),
  );
};

// stringTest :: Any -> Boolean
const stringTest = $.test ([]) ($.String);

// naiveEmailStrTest :: String -> Boolean
const naiveEmailStrTest = R.test (/^[a-z0-9_.]+@[a-z0-9_.]+$/i);

// idStrTest :: String -> Boolean
const idStrTest = R.test (/^[a-z0-9_]+$/i);

// custom types
const Email = $.NullaryType (
  funcName ('Email'),
  docsLink ('Email'),
  R.both (stringTest) (naiveEmailStrTest),
);

const ID = $.NullaryType (
  funcName ('ID'),
  docsLink ('ID'),
  R.both (stringTest) (idStrTest),
);

const EmailEntry = Model ('EmailEntry') ({
  address: Email,
  verified: $.Boolean,
});

const User = Model ('User') ({
  _id: ID,
  emails: $.Array (EmailEntry),
});

const customTypes = [Email, User, ID];

const CHECK_TYPES_FLAG = true;

const fullEnv = [...env, ...flutureEnv, ...customTypes];

const S = createS ({
  checkTypes: CHECK_TYPES_FLAG,
  env: fullEnv,
});

const def = HMD.create ({
  checkTypes: CHECK_TYPES_FLAG,
  env: fullEnv,
});

const getMaybeEmailByUser = def (
  'getEmailByUser :: User -> Maybe Email',
  S.gets (R.is (String)) (['emails', '0', 'address']),
);

describe ('hm def with custom types', () => {
  it ('should allow to define custom type', () => {
    const expectedEmail = '[email protected]';
    const fakeUser = {
      _id: 'fake_user_id',
      emails: [{ address: expectedEmail, verified: false }],
    };
    const maybeEmail = getMaybeEmailByUser (fakeUser);
    expect (S.fromMaybe ('na', maybeEmail)).toEqual (expectedEmail);
  });

  it ('should not fail with missing email', () => {
    const expectedEmail = 'na';
    const fakeUser = { _id: 'fake_user_id', emails: [] };
    const maybeEmail = getMaybeEmailByUser (fakeUser);
    expect (S.fromMaybe (expectedEmail, maybeEmail)).toEqual (expectedEmail);
  });

  it ('should fail when returned type is incorrect', () => {
    const fakeUser = { _id: 'fake_user_id', emails: [] };

    const getOnlyEmailByUser = def (
      'getOnlyEmailByUser :: User -> Email',
      R.compose (
        S.fromMaybe ('n/a'),
        getMaybeEmailByUser,
      ),
    );

    expect (() => {
      getOnlyEmailByUser (fakeUser);
    }).toThrow ();
  });

  it ('should work for some simple calculate', () => {
    const calcInRange = def (
      'calcInRange :: Number -> Number',
      S.pipe ([
        S.range (0),
        S.map (S.add (1)),
        S.map (R.multiply (2)),
        S.reduce (S.add, 0),
      ]),
    );

    const testRange = S.pipe ([S.range (0), S.map (R.multiply (10))]) (10);
    const testResults = S.map (calcInRange) (testRange);
    const zippedList = R.zip (testRange) (testResults);
    expect (zippedList).toMatchSnapshot ();
  });

  it ('should support fluture', async () => {
    const futureIncrement = def (
      'futureIncrement :: Number -> Future String Number',
      S.pipe ([S.add (1), F.of]),
    );

    await expect (futureIncrement (5).promise ()).resolves.toEqual (6);
  });
});