vimeo/psalm

TypeDoesNotContainType - 5:4 - Cannot resolve types for $str2 - non-empty-lowercase-string does not contain non-falsy-string

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#9,733 opened on May 3, 2023

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 (2 comments) (0 reactions) (0 assignees)PHP (5,369 stars) (668 forks)batch import
Help wantedbugeasy problems

Description

In the following example https://psalm.dev/r/95834da943 I expect to see no errors. A non-falsy-string should be comparable to lowercase-string.

Contributor guide

Tech stack
None
Domain
tooling
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.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Familiarity with PHP static analysisUnderstanding of Psalm type systemAbility to navigate Psalm source code
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate Psalm's type comparison logic, specifically files like src/Psalm/Type/Comparator.php and src/Psalm/Internal/Analyzer/Statements/Expression/BinaryOp/ComparisonAnalyzer.php. The issue involves comparing non falsy string to lowercase string. Reproduce using the provided Psalm playground link. Look at existing tests in tests/TypeReconciliation/ for similar type combinations. Consider adding a test case that demonstrates the expected behavior.