uber/NullAway

Disallow writing `@Initializer` on constructors

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#540 opened on Jan 6, 2022

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 (0 comments) (0 reactions) (0 assignees)Java (3,462 stars) (288 forks)batch import
good first issue

Description

If a constructor is annotated with @Initializer, NullAway currently treats the constructor as if it were an initializer method that runs after any constructor, which clearly doesn't make sense. Instead, NullAway should report an error, as this is an invalid use of @Initializer.

Contributor guide

Tech stack
java
Domain
backendtooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Javaannotation processing basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55
Research direction
Look at NullAway's source code to understand how `@Initializer` is currently validated, likely in a handler or checker class. Examine existing checks for invalid annotation usage patterns, such as `@NonNull` on primitives. Add a new check that detects when `@Initializer` is applied to a constructor and reports an error. Consider writing a unit test to verify the behavior. Refer to issue #540 and the file `com/uber/nullaway/NullAway.java` or similar.