Lodash fork with Pythagora tests

If you want to try it out yourself, just clone the repo and run:

npm i
npx jest ./pythagora_tests/

Bugs that Pythagora tests caught:

Edge cases

1. size gets tricked if there is an object with a length property:

   // _.size should return the size of an object which is this case should be 3
   // but it returns 9
   test(`size({ 'a': 1, 'b': 2, 'length': 9 })`, () => {
     expect(size({ 'a': 1, 'b': 2, 'length': 9 })).toBe(3); // test returns 9
   });
   

---

Bugs that are in the master branch

P.S. The following bugs are NOT in the latest version of Lodash (4.17.15) but only in the master branch that is 400 commits in front of the branch 4.17. I'm not sure how Lodash team works with the master branch so don't want to come across negatively towards them if they have other workflows that allow master branch to be unstable. This is just to showcase bugs that Pythagora is able to detect.

1. forOwnRight doesn't add to array as intended:

   test('should call iteratee in reverse order', () => {
     const Foo = function() {
       this.a = 1;
       this.b = 2;
     };
   
     Foo.prototype.c = 3;
   
     const result = [];
     const iteratee = (value, key) => {
       result.push(key);
     }
   
     forOwnRight(new Foo, iteratee);
   
     // `result` should be ['b', 'a'] while in the test it's [[Function iteratee], [Function iteratee]]
     expect(result).toEqual(['b', 'a']);
   });
   

2. orderBy

   test('users with custom compare functions', () => {
     const output = orderBy(users, ['user', 'age'], [
       (a, b) => a.localeCompare(b, 'de', { sensitivity: 'base' }),
       (a, b) => a - b,
     ]); // error is thrown here
     expect(output).toHaveLength(users.length);
     expect(_.isEqual(output, [
       { 'user': 'barney', 'age': 34 },
       { 'user': 'barney', 'age': 36 },
       { 'user': 'fred', 'age': 40 },
       { 'user': 'fred', 'age': 48 }
     ])).toBe(true);
   });
   
   // docs say that iteratee should be type string[]
   // but in this test, it throws an error `TypeError: iteratee is not a function` on the first line
   // there is acually the same example in the docs
   test('users', () => {
     const output = orderBy(users, ['user', 'age'], ['asc', 'desc']); // error is thrown here
     expect(output).toHaveLength(users.length);
     expect(_.isEqual(output, [
       { 'user': 'barney', 'age': 36 },
       { 'user': 'barney', 'age': 34 },
       { 'user': 'fred', 'age': 48 },
       { 'user': 'fred', 'age': 40 }
     ])).toBe(true);
   });
   

3. pick

   // Test should return `{"a": 1, "c": 3}` but it returns `{}`
   test('pick({"a": 1, "b": "2", "c": 3}, ["a", "c"])', () => {
     expect(pick({"a": 1, "b": "2", "c": 3}, ["a", "c"])).toEqual({"a": 1, "c": 3}); // test returns false
   });
   
   // Test should return `{"b":{"c":2}}` but it returns `{}`
   test('pick({"a": 1, "b": {"c": 2, "d": 3}}, ["b.c"])', () => {
     expect(pick({"a": 1, "b": {"c": 2, "d": 3}}, ["b.c"])).toEqual({"b": {"c": 2}}); // test returns false
   });
   
   // Test should return `{"a": 1, "c": 3}` but it returns `{}`
   test('pick({"a": 1, "b": "2", "c": 3}, ["a", "c", "d"])', () => {
     expect(pick({"a": 1, "b": "2", "c": 3}, ["a", "c", "d"])).toEqual({"a": 1, "c": 3}); // test returns false
   });
   

4. zipWith fails when there is no iteratee defined:

   // Test should return `[[1,4],[2,5],[3,6]]` but it throws an error `Cannot read properties of undefined (reading 'apply')`
   test('3', () => {
     expect(zipWith([1, 2, 3], [4, 5, 6])).toEqual([[1, 4], [2, 5], [3, 6]]); // test returns false
   });
   
   // Test should return `[[1,3],[2,4]]` but it throws an error `Cannot read properties of undefined (reading 'apply')`
   test('5', () => {
     expect(zipWith([1, 2], [3, 4])).toEqual([[1, 3], [2, 4]]); // test returns false
   });
   
   // Test should return `[[1],[2]]` but it throws an error `Cannot read properties of undefined (reading 'apply')`
   test('6', () => {
     expect(zipWith([1, 2])).toEqual([[1], [2]]); // test returns false
   });
   

5. update

   // `update` variable in this test should be `{"a":[{"b":{"c":3}}],"x":[{"y":{"z":0}}]}`
   // but instead it is `{"a":[{"b":{"c":3}}],"x":[{"y":{}}]}` - missing the `z` property
   test('3', () => {
     const object = { a: [{ b: { c: 3 } }] };
     update(object, 'x[0].y.z', n => (n ? n + 1 : 0));
     expect(object).toEqual({ a: [{ b: { c: 3 } }], x: [{ y: { z: 0 } }] }); // test returns false
   });