What Simple Validation Mistakes Reveal About Real‑World Testing

Background

After finishing development of an internal project, the author performed a few days of self‑testing with only smoke and positive‑path cases. When a dedicated web tester joined, several bugs surfaced, prompting a deeper look at the root causes.

Character‑Length Issue

Test case names were originally limited to 32 characters based on the developer’s assumption that longer names would be hard to display. The product specification, however, explicitly required a length of 1‑60 characters. To comply, the author had to modify both the front‑end validation and the database column definition, which was cumbersome.

This mismatch illustrated a common problem: developers focus on implementing features while neglecting detailed product constraints, leading to boundary‑value test cases that fail.

Personal Takeaway on Testing

When time is tight, functional delivery often takes precedence over edge‑case handling. Without a unified set of constraints, developers must constantly refer to product documentation, increasing the risk of omissions. Only professional testing reliably uncovers such issues, and fixing them becomes straightforward once identified.

Technical Documentation and Default Values

The project included several filter dropdowns (e.g., environment , service , module , interface , is self , is usable , related project ). Each option was optional but required a default value, typically sourced from the back‑end.

Two default‑value strategies existed:

Page default is empty, API receives an empty string.

Page default is All, API receives an integer (currently 0).

During API contract discussions, handling both strategies proved cumbersome, so the team standardized on the 1 approach (using the product document as the authority) and kept both states simultaneously.

Unified Validation Approach

The author recommends adopting a single, consistent validation scheme for both front‑end and back‑end. Using validation annotations to enforce parameter rules reduces maintenance overhead and prevents divergent validation logic across endpoints.

Key lessons include:

Establish uniform standards early.

Document constraints comprehensively.

Create technical documentation that is clear and directly reflects product specifications.

Develop overarching rules that can supersede individual product documents when necessary.

These practices help limit the effort required for future changes and improve overall software quality.