London | 25-ITP-Sept | Samuel Tarawally | Sprint 3 | Implement and rewrite tests

[Tarawally]

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

• Implemented all solution functions in the implement folder.
• Added tests for each function using assertions.
• Rewrote all tests in Jest in the rewrite-tests-with-jest folder.
• Covered all main and edge cases as required.

[cjyuan]

In JavaScript, strings that represent valid numeric literals in the language can be safely
converted to equivalent numbers or parsed into a valid integers.
Do you want to recognize these string values as valid ranks?

To find out what these strings are, you can ask AI

What kinds of string values would make parseInt(rank) evaluate to 2 in JS?

[Tarawally]

My understanding is that the parseInt function converts a string to an integer by parsing its leading numerical characters:

parseInt(" 7abc")   // returns 7  

Given this, my current code would accept "03", for example, and this clearly isn't a valid rank. A better approach I think is to use a conditional statement which explicitly checks the rank against a limited set of numeric literals.

Is my understanding correct here, @cjyuan?

[cjyuan]

If we were to recognise only the 13 possible ranks, then a stricter check would be needed.

Can you figure out exactly how to implement them (as an exercise)?

[Tarawally]

Suggested change

	const numValue = parseInt(rank);
	if (numValue >= 2 && numValue <= 9) return numValue;
	function getCardValue(card) {
	const rank = card.slice(0, -1);
	if (rank === "A") return 11;
	if (rank === "J" || rank === "Q" || rank === "K") return 10;
	const numRanks = ["2", "3", "4", "5", "6", "7", "8", "9", "10"];
	if (numRanks.includes(rank)) {
	return Number(rank);
	}
	throw new Error("Invalid card rank");
	}

[cjyuan]

I think 10 is considered a number card.

[Tarawally]

Yes, it is. I will update the test to count 10 as a number card and change the test descriptions to reflect this.

[cjyuan]

Changes look good. Well done!