Manchester | 26-ITP-Jan | Abdu Hassen | Sprint 1| Data-Grouping by Abduhasen · Pull Request #1120 · CodeYourFuture/Module-Data-Groups

Abduhasen · 2026-03-27T21:34:07Z

Learners, PR Template

Self checklist

I have titled my PR with Region | Cohort | FirstName LastName | Sprint | Assignment Title
My changes meet the requirements of the task
I have tested my changes
My changes follow the style guide

Changelist

-fixing and implementing of data on Javascript using loop,if statement.
-testing code using jest.

Questions

N/A

cjyuan · 2026-03-31T17:27:18Z

Sprint-1/fix/median.js

+    return null;
+  }
+
+  list = list.filter((value) => typeof value === "number");


Do you plan to consider also -Infinity, Infinity, and NaN in the median calculation (and in the functions in implement/max.js and implement/sum.js)?

to handle all type of input i changed the filter , using built in method of Number.isFinite(value) can handle all type of values.

Why not apply the change also to findMax() and sum()?

Sprint-1/fix/median.js

cjyuan · 2026-03-31T17:30:24Z

Sprint-1/fix/median.js

+    return (list[middleIndex - 1] + list[middleIndex]) / 2;
+  } else {
+    const middleIndex = Math.floor(list.length / 2);
+    const median = list.splice(middleIndex, 1)[0];


Why not use the same syntax you were using on line 24 to access an array element?

i was writing the codes each one by one that why i forgot to combine them and some times little bit confusing putting line of codes together if you have any recommendation of books or techniques that i can read that would be helpful. thank you.

After the implemented function is working correctly, we should refactor our code to further improve the code. The process involves reviewing the code carefully, and reading code is a skill that takes time to develop (through reading and writing more code).

If you want something to read, you can try https://javascript.info/

Sprint-1/implement/dedupe.test.js

Sprint-1/implement/max.test.js

Sprint-1/implement/sum.js

Sprint-1/implement/sum.test.js

Sprint-1/implement/dedupe.js

cjyuan · 2026-04-04T16:11:35Z

Sprint-1/implement/dedupe.test.js

+test("The function should return a copy of the original array if the array contains no duplicates", () => {
+  const original = [2, 4, 5, 6, 8];
+  expect(dedupe(original)).toEqual(original);
+  expect(dedupe(original)).not.toBe(original);
+});


There is a chance that, even though the return value has incorrect elements (for example, [2, 2, 2, 2, 2]),
the two tests could still pass. Can you figure out why, and then fix the tests accordingly?

i did some fixation now it is improved.

It is not about how many sets of data you are testing, the issue in "how" you carry out the test.

Don't think how you implement your function. Think about under what condition a buggy function that returns [2, 2, 2, 2, 2] can possibly pass the test.

cjyuan · 2026-04-04T16:26:24Z

Sprint-1/implement/sum.test.js

+  expect(sum([7.8045, 1.273, 3.19])).toBeCloseTo(12.2675, 4);
+  expect(sum([4.6, 1.8, 3.18, 5.4])).toBeCloseTo(14.98);
+  expect(sum([11 / 12, 4 / 6, 1 / 2, 6 / 20])).toBeCloseTo(2.383333, 6);
+  expect(sum([1 / 2, 2 / 3, 3 / 4, 4 / 5, 5 / 6, 6 / 7])).toBeCloseTo(
+    4.407142857,
+    9
+  );


Why specify different "number of decimal places" in your tests?

Because the more decimal places I expected value has, the stricter my test needs to be.

Why not just enforce the strictest tolerable difference?

If the function can pass this test
expect(sum([7.8045, 1.273, 3.19])).toBeCloseTo(12.2675, 9);
then the function will also pass
expect(sum([7.8045, 1.273, 3.19])).toBeCloseTo(12.2675, 4);

For adding only a few numbers, the rounding error will be very small. So it's ok to be strict.

ok i will implement that in fact in this test i did that the test go through all the decimal numbers until the end that's why i specified each decimal number to test.

cjyuan

You have all the info to further improve the code. I will mark this PR as complete first.

cjyuan · 2026-04-05T17:12:44Z

Sprint-1/implement/dedupe.test.js

+  expect(original1.length).toBe(new Set(original1).size);
  const result1 = dedupe(original1);
  expect(result1).toEqual(original1);
  expect(result1).not.toBe(original1);


If their length is different, toEqual() would also fail.

Objects (including arrays) are passed to a function by reference, meaning that the they have a chance to be mutated by the function. So on line 30, it is safer to write expect(reuslt1).toEqual('[2,4,5,6,8]').

complete of sprint 1 of Data-Grouping

55e404b

Abduhasen added 📅 Sprint 1 Assigned during Sprint 1 of this module Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. Module-Data-Groups The name of the module. labels Mar 27, 2026

cjyuan reviewed Mar 31, 2026

View reviewed changes

cjyuan added Reviewed Volunteer to add when completing a review with trainee action still to take. and removed Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Mar 31, 2026

Abduhasen added 2 commits April 4, 2026 08:37

changed the filter method base on mentor feedback

c07db61

fixing the code base on mentor feedback

f2129f5

Abduhasen added Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. and removed Reviewed Volunteer to add when completing a review with trainee action still to take. labels Apr 4, 2026

cjyuan reviewed Apr 4, 2026

View reviewed changes

cjyuan added Reviewed Volunteer to add when completing a review with trainee action still to take. and removed Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Apr 4, 2026

fixing based on mentor feedback

51e3a0b

Abduhasen added Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. and removed Reviewed Volunteer to add when completing a review with trainee action still to take. labels Apr 4, 2026

cjyuan added Reviewed Volunteer to add when completing a review with trainee action still to take. and removed Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Apr 5, 2026

adding restriction on the test

760695c

Abduhasen added Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. and removed Reviewed Volunteer to add when completing a review with trainee action still to take. labels Apr 5, 2026

cjyuan reviewed Apr 5, 2026

View reviewed changes

cjyuan added Complete Volunteer to add when work is complete and all review comments have been addressed. and removed Needs Review Trainee to add when requesting review. PRs without this label will not be reviewed. labels Apr 5, 2026

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Abduhasen commented Mar 27, 2026

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