Why is Composer Warning About PSR-4 Autoloading Incompliance?

Composer Deprecation Notice: Class Mapping Incompliance with PSR-4

Composer issues a warning, "Class FooBarBaz located in ./foo/bar/utility/baz.php does not comply with psr-4 autoloading standard. Skipping," indicating a potential issue with PSR-4 adherence.

Reasons for the Notice

• Path Case Mismatch: The case of the path components in the file's pathname must align with the case used in the corresponding fully qualified class name.
• Filename and Class Name/Namespace Differences: The filename and fully qualified class (or namespace) names should match precisely. Any discrepancy can trigger a warning.
• Nested Namespaces and Missing Declaration: If nested namespaces are used, they must be explicitly declared in the corresponding autoloader configuration.

Remediation Steps

• Path Case Verification: Ensure that the case of the path components in the file's pathname matches the case used in the fully qualified class name.
• Filename and Class Name/Namespace Alignment: Double-check the filename and fully qualified class name to ensure they match perfectly. Consider renaming files or class/namespace names if necessary.
• Nested Namespace Declaration: For nested namespaces, ensure that the appropriate namespace is declared in the autoloader configuration and that the class is declared within the correct subdirectory of the declared namespace.

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