---
title: "Test Coverage"
url: https://daily.dev/posts/test-coverage-mjwjqvjwp
source_url: https://www.youtube.com/watch?v=tXI0fK_6x9Y
type: video:youtube
source: "ThePrimeTime"
published: 2026-06-06T13:20:00.395Z
updated: 2026-06-06T13:20:16.428Z
tags: ["testing"]
reading_time: 1
upvotes: 0
comments: 0
language: en
---

> ## Documentation Index
> Fetch the complete documentation index at: https://daily.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Test Coverage

**[ThePrimeTime](https://daily.dev/sources/primeagen)** · 1 min read · 0 upvotes · 0 comments

## Summary

A rant arguing that 100% test coverage does not guarantee bug-free code. Using a live coding example, the author demonstrates how a function can have full test coverage yet still contain a bug, making the point that tests only catch bugs you already know to write tests for — not unknown bugs.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://www.youtube.com/watch?v=tXI0fK_6x9Y>

## Similar posts on daily.dev

- [100% coverage is not that trivial](https://daily.dev/posts/100-coverage-is-not-that-trivial-olrpmqi6o) · ploeh blog · 30 upvotes · 5 comments

---

Tags: [#testing](https://daily.dev/tags/testing)

[View this post on daily.dev](https://daily.dev/posts/test-coverage-mjwjqvjwp)