saveourtool/diktat

Optional rule: require should have a message unless it's inside code from tests

Open

#838 opened on Apr 22, 2021

View on GitHub
 (1 comment) (0 reactions) (1 assignee)Kotlin (40 forks)github user discovery
enhancementgood first issue

Repository metrics

Stars
 (571 stars)
PR merge metrics
 (PR metrics pending)

Description

Preconditions from Kotlin stdlib (require, requireNotNull) accept an optional message parameter. If it's not set, failed precondition results in exceptions like Requirement failed at class:line:col. This is not useful and confusing. Unless require or requireNotNull is used in tests, it should be provided with exception message.

require(a.condition())
requireNotNull(b)

should be something like

require(a.condition()) { "Condition is not met for $a" }
requireNotNull(b) { "b is not set" }

Sure, we can't suggest exact text of these messages, so the possible inspection should only warn.

Contributor guide

Research direction
Implement a rule to detect require and requireNotNull calls without a message argument, excluding test code. The rule should warn about missing messages.
Tech stack
kotlin
Domain
tooling
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Kotlin
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70