Сhecking a key in an array in another function PossiblyUndefinedIntArrayOffset

Repository metrics

Stars

5,369 stars (5,369 stars)

PR merge metrics

Avg merge 3d 12h (Avg merge 3d 12h)5 merged PRs in 30d (5 merged PRs in 30d)

Description

Contributor guide

Research direction

Review the provided Psalm sandbox example (https://psalm.dev/r/f1c0b3b1ba) to understand the false positive for PossiblyUndefinedIntArrayOffset. Then, investigate the Psalm source code, particularly the logic in the array analysis that handles function calls and key existence checks. Look for where the analysis incorrectly assumes an offset is undefined when it is actually defined via a function call within another function. Trace the control flow and type inference to identify the bug.

Tech stack

php

Domain

developer experiencetooling

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.

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

PHPBasic understanding of Psalm

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

70