All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

• Restore version and dependabot updates from the 2.x branch.

This is preparing for a major 3.0 release which adds a dependency on PHPCSUtils. The new version should have the same functionality, fix some subtle bugs, and increase performance by over 2x.

• Add PHPCSUtils as a dependency.
• Bump minimum PHPCS version from 3.5.7 to 3.13.5.

• Simplify getUseIndexForUseImport using findContainingOpeningBracket().
• Replace findFunctionCallArguments custom loop with PassedParameters::getParameters().
• Replace isConstructorPromotion manual scan with FunctionDeclarations::getParameters().
• Replace areAnyConditionsAClass manual loop with Conditions::hasCondition().
• Simplify getListAssignments using Lists::getAssignments.
• Replace findContainingOpeningBracket with the PHPCSUtils equivalent.
• Replace isVariableInsideUnset/isVariableInsideIssetOrEmpty with PHPCSUtils equivalents.
• Simplify arrow function detection by relying on T_FN.
• Remove unnecessary isArrowFunction block in getScopeCloseForScopeOpen.

• Ruleset: update schema URL (#353).
• Update for PHPCS 4.0.0 (#356).

• Accept namespaces in sitePassByRefFunctions (#351).
• GH Actions: use the xmllint-validate action runner (#350).

• Allow finding arrow function variables when the arrow function is in file scope (#347).
• Add perf-guard GitHub workflow (#345).
• Improve PHPStan configuration (#344).

• Only search for nested arrow functions if necessary (#342).

• Support nested arrow functions (#334).
• Simplify detecting class properties to improve detection for anonymous classes (#337).
• Handle compact inside arrow functions (#339).
• Support constructor promotion with namespaced and union typehints (#333).
• Various housekeeping: prevent a Composer lock file (#326), Psalm 5 (#327), PHPUnit 10/11 support (#328), PHP 8.4 in CI (#336), and run static analysis on PHP 8.1 (#338).

• Fix: process variable before the end of scope (#324).
• GH Actions: work around intermittent apt-get errors (#322).

• Switch to PHPCSStandards/PHP_CodeSniffer (#315).
• Make sure that recursive search of list assignments stays inside them (#318).
• Fix nullable constructor promotion detection (#321).

• Do not close scope of ref reassignment when inside else (#306).

• Allow newlines in arrow functions (#301).

• Fix scope closer detection in arrow function detection (#298).

• Use custom logic for finding arrow function scope (#296).

• Support readonly constructor promotion (#294).

• Allow non-enum tokens called 'enum' (#293).

• Add support for enum methods (#289).

• Composer: allow for the 1.0.0 version of the Composer PHPCS plugin (#287).

• Prevent detecting static closures when looking for static variables (#281).

• Fix function call detection to exclude non-function tokens (#279).

• Place static arrow function body outside of scope on static declaration check (#276). Fixes a static variable regression from #267.

Bug fix release for two regressions caused by the new static function variable scanning added in #267.

• Ignore function call arguments on static declarations processing (#273).
• Fix scanning for static variables near start of file (#274).

• Allow for loop increment expression to use a variable defined inside the loop (#262).
• Support constructor promotion (#266).
• Improve static declaration checks (#267).
• Handle inline if list destructure (#268).
• Remove php_errormsg from superglobals list (#269).
• Ignore unused parameters when a function in an abstract class is empty (#270).

• Fix a deprecation notice in PHP 8.2 (#248), plus internal housekeeping.

• Update for Composer 2.2 (#242).

• Respect ignoring undefined variables in else blocks (#239).

• Allow parsing mixed HTML and PHP (#234, #236).
• Ignore double assignment by reference if the second is inside a condition (#235).

• Start inline block scope at end of condition rather than at keyword (#230).
• Add allowUnusedVariablesInFileScope option (#229).

• Treat writing to a by-reference foreach loop variable as a read (#221).
• Properly detect variables used in quotes inside arrow functions (#222).

• Performance: only check one parent for recursive list assignment (#218). In at least one example file this brought the speed from 7 minutes down to 0.3 seconds.

A large release that backports nearly all the improvements made on the 3.0 branch to the 2.x line, with the major exception of adding PHPCSUtils as a dependency.

Notable changes since 2.9:

• Fix array_walk pass-by-reference in 2.x (#216).
• Support for PHP 7.4 arrow functions (#179).
• Rewritten and more accurate scope detection.
• Allow undefined variables inside isset and empty (#204).
• Fix error in closures with namespace separators (#197).
• Fix complex default arguments (#198).
• Handle inline if/else (#199).
• Add allowUndefinedVariablesInFileScope option (#193).
• Add allowUnusedVariablesBeforeRequire option (#196).
• Support global scope (#190).
• Add validUndefinedVariableRegexp option (#173).
• Refactor and clean up reference variables (#187).
• Add special cases for variables used in else blocks (#189).

Note: this release intentionally excludes breaking changes from the 3.0 branch, namely replacing UnusedVariable with UnusedParameter for parameters (#195) and adding sniff codes for the array assignment shortcut (#205).

Backports some 3.x features to the 2.x line.

• Add allowUnusedVariablesBeforeRequire option (originally #196).
• Add allowUndefinedVariablesInFileScope option (originally #193).

• Downgrade requirements from PHP 5.6 to 5.4 (#191, backported to 2.x).

A backport of the bugfixes from 3.0.0-beta.1 into the 2.x version without any of the PHPCSUtils changes.

• Fix comment tolerance for many sniffs.
• Clean up package structure.
• Only allow unused values in associative foreach loops with option (#167).
• Fix unused-before-used detection (#171).

A small bug fix release with test and package clean-up.

• Make assignment of a reference variable be considered a use (#128).
• Bug fix: false negative unused var (#120).
• Bug fix: $this in nested function declaration (#119).
• Bug fix: recognize use of self/static within an anonymous class (#110).
• PHPStan: document run parameters in project ruleset (#122).
• Composer: update PHPCS Composer plugin dependency (#121), move PHPCS dependency to require (#106), update DealerDirect Composer plugin requirement (#112).
• Documentation: minor fixes (#123).
• Tests: simplify the PHPCS setup method (#115), allow them to work cross-platform (#108), add testsuite name to PHPUnit config (#113).
• Remove stray composer.lock file (#117).
• Composer: make the PHPUnit requirements more flexible (#114).
• PHPCS: document run parameters in project ruleset (#107).

• Add apcu_* functions to getPassByReferenceFunctions (#103).
• Add sniff codes to README (#100).
• Mention phpcs-changed in README (#97).
• Update README to include PHPStan and linting (#96).
• Refactor methods to have nullable return types (#95).
• Tests: make sure fixtures are valid PHP.

• Consider get_defined_vars() to be a read (#92).
• Use static analysis to remove edge case bugs (#94).

• Recognize that variable variables are not assignments (#88).

• Downgrade CircleCI image to PHP 5.6 (#86). Fixes a PHP 5.6 regression introduced in 2.6.2 and corrects the Composer minimum PHP version.

• Allow global var assignment to count as a read (#83).

• Improve check for static var defs inside functions (#80).
• Allow self and static references in a trait (#76).
• Add checks for class properties (#77).

• Enable allowUnusedForeachVariables and allowUnusedCaughtExceptions (#73).

• Add ignore unused foreach option (#66).
• Allow self within class method closures (#70).
• Add allowWordPressPassByRefFunctions option (#69).
• Document site pass by ref (#71).

• Handle variable class static refs (#63).
• Ignore numeric variables (#61).
• Make allowUnusedParametersBeforeUsed default to true (#59).

• Add allowUnusedParametersBeforeUsed option (#58).

• Add option for undefined vars (#56).

• Support shorthand list assignment (#50).
• Correctly mark pass-by-reference variables in use() constructs (#54).
• Support anonymous classes (#53).
• Build: rename the config files (#49).

• Remove typehints to support PHP 5 (#47).

• Include parent keyword as a static reference (#44).

• Allow unused function arguments as regexp (#22).
• Treat trait properties as definitions (#40).

• Fix broken foreach variable identification (#36). Fixes a major regression caused by #35.

⚠️ DO NOT USE THIS VERSION, IT HAS A MAJOR REGRESSION FIXED IN 2.0.7.

• Allow list to declare vars in foreach (#35).

• Fix recognition of static variable functions (#27).
• Simplify handling static variables (#32).
• Allow traits to use $this (#25).
• Remove null coalesce (#31).
• Move library files to the Lib directory and namespace (#28).
• Code cleanup (#29, #30) and test improvements (#23, #24).

• Allow using $this in closures (#20).

• Fix a bug that could occur where a variable was used within the same parenthesis-wrapped expression (e.g. function call arguments) but after a comma (#13).

• Disable the roave/security-advisories dependency because it required developers to add additional lines to their composer.json.

• Re-enable sniffs that were accidentally disabled, particularly unused function arguments.

• Reorganize the source so it can be more easily referenced in a ruleset (#2).

• Initial release.