lodash-contrib/test/object.selectors.js

The brass buckles on lodash's utility belt

$(document).ready(function() {

  module("lodash.object.selectors");

  test("accessor", function() {
    var a = [{a: 1, b: 2}, {c: 3}];

    equal(_.accessor('a')(a[0]), 1, 'should return a function that plucks');
    equal(_.accessor('a')(a[1]), undefined, 'should return a function that plucks, or returns undefined');
    deepEqual(_.map(a, _.accessor('a')), [1, undefined], 'should return a function that plucks');
  });

  test("dictionary", function() {
    var a = [{a: 1, b: 2}, {c: 3}];

    equal(_.dictionary(a[0])('a'), 1, 'should return a function that acts as a dictionary');
    equal(_.dictionary(a[1])('a'), undefined, 'should return a function that acts as a dictionary, or returns undefined');
  });

  test("selectKeys", function() {
    deepEqual(_.selectKeys({'a': 1, 'b': 2}, ['a']), {'a': 1}, 'shold return a map of the desired keys');
    deepEqual(_.selectKeys({'a': 1, 'b': 2}, ['z']), {}, 'shold return an empty map if the desired keys are not present');
  });

  test("kv", function() {
    deepEqual(_.kv({'a': 1, 'b': 2}, 'a'), ['a', 1], 'should return the key/value pair at the desired key');
    equal(_.kv({'a': 1, 'b': 2}, 'z'), undefined, 'shold return undefined if the desired key is not present');
  });

  test("getPath", function() {
    var deepObject = { a: { b: { c: "c" } }, falseVal: false, nullVal: null, undefinedVal: undefined, arrayVal: ["arr"] };
    var deepArr = [[["thirdLevel"]]];
    var ks = ["a", "b", "c"];

    strictEqual(_.getPath(deepObject, ks), "c", "should get a deep property's value from objects");
    deepEqual(ks, ["a", "b", "c"], "should not have mutated ks argument");
    strictEqual(_.getPath(deepArr, [0, 0, 0]), "thirdLevel", "should get a deep property's value from arrays");
    strictEqual(_.getPath(deepObject, ["arrayVal", 0]), "arr", "should get a deep property's value from nested arrays and objects");

    strictEqual(_.getPath(deepObject, ["undefinedVal"]), undefined, "should return undefined for undefined properties");
    strictEqual(_.getPath(deepObject, ["a", "notHere"]), undefined, "should return undefined for non-existent properties");
    strictEqual(_.getPath(deepObject, ["nullVal"]), null, "should return null for null properties");
    strictEqual(_.getPath(deepObject, ["nullVal", "notHere", "notHereEither"]), undefined, "should return undefined for non-existent descendents of null properties");

    strictEqual(_.getPath(deepObject, "a.b.c"), "c", "should work with keys written in dot notation");
  });

  test("hasPath", function() {
    var deepObject = { a: { b: { c: "c" } }, falseVal: false, numberVal: 123, stringVal: 'str', nullVal: null, undefinedVal: undefined, arrayVal: ["arr"] };
    var ks = ["a", "b", "c"];

    strictEqual(_.hasPath(deepObject, ["notHere", "notHereEither"]), false, "should return false if the path doesn't exist");
    strictEqual(_.hasPath(deepObject, ks), true, "should return true if the path exists");
    deepEqual(ks, ["a", "b", "c"], "should not have mutated ks argument");

    strictEqual(_.hasPath(deepObject, ["arrayVal", 0]), true, "should return true for an array's index if it is defined");
    strictEqual(_.hasPath(deepObject, ["arrayVal", 999]), false, "should return false for an array's index if it is not defined");

    strictEqual(_.hasPath(deepObject, ["nullVal"]), true, "should return true for null properties");
    strictEqual(_.hasPath(deepObject, ["undefinedVal"]), true, "should return true for properties that were explicitly assigned undefined");

    strictEqual(_.hasPath(deepObject, ["nullVal", "notHere"]), false, "should return false for descendants of null properties");
    strictEqual(_.hasPath(deepObject, ["undefinedVal", "notHere"]), false, "should return false for descendants of undefined properties");
    strictEqual(_.hasPath(deepObject, ["falseVal", "notHere"]), false, "should return false for descendants of a boolean literal");
    strictEqual(_.hasPath(deepObject, ["stringVal", "notHere"]), false, "should return false for descendants of a string literal");
    strictEqual(_.hasPath(deepObject, ["numberVal", "notHere"]), false, "should return false for descendants of a number literal");

    strictEqual(_.hasPath(deepObject, "a.b.c"), true, "should work with keys written in dot notation.");
  });

  test("pickWhen", function() {
    var a = {foo: true, bar: false, baz: 42};

    deepEqual(_.pickWhen(a, _.truthy), {foo: true, baz: 42}, "should return an object with kvs that return a truthy value for the given predicate");
  });

  test("omitWhen", function() {
    var a = {foo: [], bar: "", baz: "something", quux: ['a']};

    deepEqual(_.omitWhen(a, _.isEmpty), {baz: "something", quux: ['a']}, "should return an object with kvs that return a falsey value for the given predicate");
  });
});