Validation
56 bites tagged Validation — interview questions with model answers, and 60-second explainers.
FastAPI: Validate Parameters with Query and Path
FastAPI's `Query` and `Path` objects let you declare rich validation rules directly in your function's signature. Enforce string lengths, regex patterns, or numeric ranges on URL parameters without writing manual checks.
Generative vs. Evaluative Research: Define Problems vs. Judge Solutions
Generative research defines problems by asking, "What should we build?" Evaluative research judges solutions by asking, "Did we build it right?" The footgun is using evaluative methods for discovery, which just optimizes a solution for a problem nobody has.
Never Trust Client Input: API Validation
Think of API validation as a bouncer for your server, checking every incoming request's ID before it can access your application logic. Use it in any Express route that accepts user input to prevent bad data from hitting your database or causing errors.
Never Trust User Input: The Validation Mindset
Treat all incoming data as hostile until proven otherwise. Input validation ensures only properly formed data enters your system, protecting against errors and attacks. It applies to user forms, APIs, and partner feeds.
Joi: Declarative Schemas for Data Validation
Joi lets you describe your data's shape with a readable schema instead of writing manual validation logic. It's used to validate API request bodies or config files.
Mongoose Validation: Your Schema's Built-in Guard
Mongoose validation is a guard at the application layer, ensuring data conforms to schema rules before hitting the database. Use it for required fields, lengths, and ranges. The `unique` option is for database indexes, not a Mongoose validation rule.
Flutter's Form Widget: Grouping and Validating Input
A Flutter `Form` acts as a supervisor for multiple input fields, letting you validate and save them all at once. Use it for login screens or user profiles. The footgun is forgetting the `GlobalKey`, which makes it impossible to trigger validation.
Pretotyping: Build The Right It, Not Just It Right
Pretotyping tests if anyone wants your product before you build it, ensuring you build 'The Right It.' Use it to validate market demand with minimal resources, gathering real data. The footgun is confusing it with prototyping, which tests implementation.
Get Validation bites daily.
Five a day, five minutes, offline. With quizzes so it sticks.
Open testing — you’ll join as an early tester.