Core: New sniff to examine type casts

WordPress-Core/ruleset.xml

@@ -233,6 +233,7 @@
 	<rule ref="Generic.Formatting.SpaceAfterCast"/>
 	<rule ref="Squiz.WhiteSpace.CastSpacing"/>
 	<rule ref="WordPress.WhiteSpace.CastStructureSpacing"/>
+	<rule ref="WordPress.PHP.TypeCasts"/>
 
 	<!-- Covers rule: ... array items, only include a space around the index if it is a variable. -->
 	<rule ref="WordPress.Arrays.ArrayKeySpacingRestrictions"/>

WordPress/Sniffs/PHP/TypeCastsSniff.php

@@ -0,0 +1,154 @@
+<?php
+/**
+ * WordPress Coding Standard.
+ *
+ * @package WPCS\WordPressCodingStandards
+ * @link    https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards
+ * @license https://opensource.org/licenses/MIT MIT
+ */
+
+namespace WordPress\Sniffs\PHP;
+
+use WordPress\Sniff;
+use PHP_CodeSniffer_Tokens as Tokens;
+
+/**
+ * Verifies the correct usage of type cast keywords.
+ *
+ * Type casts should be:
+ * - lowercase;
+ * - short form, i.e. (bool) not (boolean);
+ * - normalized, i.e. (float) not (real).
+ *
+ * Additionally, the use of the (unset) and (binary) casts is discouraged.
+ *
+ * @link    https://make.wordpress.org/core/handbook/best-practices/....
+ *
+ * @package WPCS\WordPressCodingStandards
+ *
+ * @since   1.2.0
+ */
+class TypeCastsSniff extends Sniff {
+
+	/**
+	 * Returns an array of tokens this test wants to listen for.
+	 *
+	 * @return array
+	 */
+	public function register() {
+		return Tokens::$castTokens;
+	}
+
+	/**
+	 * Processes this test, when one of its tokens is encountered.
+	 *
+	 * @param int $stackPtr The position of the current token in the stack.
+	 *
+	 * @return void
+	 */
+	public function process_token( $stackPtr ) {
+
+		$token_code  = $this->tokens[ $stackPtr ]['code'];
+		$typecast    = $this->tokens[ $stackPtr ]['content'];
+		$typecast_lc = strtolower( $typecast );
+
+		$this->phpcsFile->recordMetric( $stackPtr, 'Typecast encountered', $typecast );
+
+		switch ( $token_code ) {
+			case \T_BOOL_CAST:
+				if ( '(bool)' !== $typecast_lc ) {
+					$fix = $this->phpcsFile->addFixableError(
+						'Short form type keywords must be used; expected "(bool)" but found "%s"',
+						$stackPtr,
+						'LongBoolFound',
+						array( $typecast )
+					);
+
+					if ( true === $fix ) {
+						$this->phpcsFile->fixer->replaceToken( $stackPtr, '(bool)' );
+					}
+				}
+				break;
+
+			case \T_INT_CAST:
+				if ( '(int)' !== $typecast_lc ) {
+					$fix = $this->phpcsFile->addFixableError(
+						'Short form type keywords must be used; expected "(int)" but found "%s"',
+						$stackPtr,
+						'LongIntFound',
+						array( $typecast )
+					);
+
+					if ( true === $fix ) {
+						$this->phpcsFile->fixer->replaceToken( $stackPtr, '(int)' );
+					}
+				}
+				break;
+
+			case \T_DOUBLE_CAST:
+				if ( '(float)' !== $typecast_lc ) {
+					$fix = $this->phpcsFile->addFixableError(
+						'Normalized type keywords must be used; expected "(float)" but found "%s"',
+						$stackPtr,
+						'DoubleRealFound',
+						array( $typecast )
+					);
+
+					if ( true === $fix ) {
+						$this->phpcsFile->fixer->replaceToken( $stackPtr, '(float)' );
+					}
+				}
+				break;
+
+			case \T_UNSET_CAST:
+				$this->phpcsFile->addWarning(
+					'Using the "(unset)" cast is strongly discouraged. Use the "unset()" language construct or assign "null" as the value to the variable instead.',
+					$stackPtr,
+					'UnsetFound'
+				);
+				break;
+
+			case \T_STRING_CAST:
+			case \T_BINARY_CAST:
+				if ( \T_STRING_CAST === $token_code && '(binary)' !== $typecast_lc ) {
+					break;
+				}
+
+				$this->phpcsFile->addWarning(
+					'Using binary casting is strongly discouraged. Found: "%s"',
+					$stackPtr,
+					'BinaryFound',
+					array( $typecast )
+				);
+				break;
+		}
+
+		/*
+		 * {@internal Once the minimum PHPCS version has gone up to PHPCS 3.3.0+, the lowercase
+		 * check below can be removed in favour of adding the `Generic.PHP.LowerCaseType` sniff
+		 * to the ruleset.
+		 * Note: the `register()` function also needs adjusting in that case to only register the
+		 * targetted type casts above and the metrics recording should probably be adjusted as well.
+		 * The above mentioned Generic sniff records metrics about the case of typecasts, so we
+		 * don't need to worry about those no longer being recorded. They will be, just slightly
+		 * differently.}}
+		 */
+		if ( $typecast_lc !== $typecast ) {
+			$data = array(
+				$typecast_lc,
+				$typecast,
+			);
+
+			$fix = $this->phpcsFile->addFixableError(
+				'PHP type casts must be lowercase; expected "%s" but found "%s"',
+				$stackPtr,
+				'NonLowercaseFound',
+				$data
+			);
+			if ( true === $fix ) {
+				$this->phpcsFile->fixer->replaceToken( $stackPtr, $typecast_lc );
+			}
+		}
+	}
+
+}

WordPress/Tests/PHP/TypeCastsUnitTest.inc

@@ -0,0 +1,49 @@
+<?php
+
+// OK.
+$a = (bool) $b;
+$a = (int) $b;
+$a = (float) $b;
+$a = (string) $b;
+$a = (array) $b;
+$a = (object) $b;
+
+// Error: Wrong form.
+$a = (boolean) $b;
+$a = (integer) $b;
+$a = (double) $b;
+$a = (real) $b;
+
+// Warning: Discouraged casts.
+$a = (unset) $b; // Warning.
+$a = (binary) $b; // Warning.
+$a = b"binary string"; // Warning. Currently false negative. Related to PHPCS bug report #1574.
+$a = b"binary $string"; // Warning.
+
+// Error: Mixed case.
+$a = (Bool) $b;
+$a = (Boolean) $b; // + wrong form.
+$a = (Int) $b;
+$a = (Integer) $b; // + wrong form.
+$a = (Float) $b;
+$a = (Double) $b; // + wrong form.
+$a = (Real) $b; // + wrong form.
+$a = (String) $b;
+$a = (Array) $b;
+$a = (Object) $b;
+$a = (Unset) $b; // + discouraged.
+$a = (Binary) $b; // + discouraged.
+
+// Error: Uppercase.
+$a = (BOOL) $b;
+$a = (BOOLEAN) $b; // + wrong form.
+$a = (INT) $b;
+$a = (INTEGER) $b; // + wrong form.
+$a = (FLOAT) $b;
+$a = (DOUBLE) $b; // + wrong form.
+$a = (REAL) $b; // + wrong form.
+$a = (STRING) $b;
+$a = (ARRAY) $b;
+$a = (OBJECT) $b;
+$a = (UNSET) $b; // + discouraged.
+$a = (BINARY) $b; // + discouraged.

WordPress/Tests/PHP/TypeCastsUnitTest.inc.fixed

@@ -0,0 +1,49 @@
+<?php
+
+// OK.
+$a = (bool) $b;
+$a = (int) $b;
+$a = (float) $b;
+$a = (string) $b;
+$a = (array) $b;
+$a = (object) $b;
+
+// Error: Wrong form.
+$a = (bool) $b;
+$a = (int) $b;
+$a = (float) $b;
+$a = (float) $b;
+
+// Warning: Discouraged casts.
+$a = (unset) $b; // Warning.
+$a = (binary) $b; // Warning.
+$a = b"binary string"; // Warning. Currently false negative. Related to PHPCS bug report #1574.
+$a = b"binary $string"; // Warning.
+
+// Error: Mixed case.
+$a = (bool) $b;
+$a = (bool) $b; // + wrong form.
+$a = (int) $b;
+$a = (int) $b; // + wrong form.
+$a = (float) $b;
+$a = (float) $b; // + wrong form.
+$a = (float) $b; // + wrong form.
+$a = (string) $b;
+$a = (array) $b;
+$a = (object) $b;
+$a = (unset) $b; // + discouraged.
+$a = (binary) $b; // + discouraged.
+
+// Error: Uppercase.
+$a = (bool) $b;
+$a = (bool) $b; // + wrong form.
+$a = (int) $b;
+$a = (int) $b; // + wrong form.
+$a = (float) $b;
+$a = (float) $b; // + wrong form.
+$a = (float) $b; // + wrong form.
+$a = (string) $b;
+$a = (array) $b;
+$a = (object) $b;
+$a = (unset) $b; // + discouraged.
+$a = (binary) $b; // + discouraged.

WordPress/Tests/PHP/TypeCastsUnitTest.php

@@ -0,0 +1,78 @@
+<?php
+/**
+ * Unit test class for WordPress Coding Standard.
+ *
+ * @package WPCS\WordPressCodingStandards
+ * @link    https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards
+ * @license https://opensource.org/licenses/MIT MIT
+ */
+
+namespace WordPress\Tests\PHP;
+
+use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+
+/**
+ * Unit test class for the TypeCasts sniff.
+ *
+ * @package WPCS\WordPressCodingStandards
+ *
+ * @since 1.2.0
+ */
+class TypeCastsUnitTest extends AbstractSniffUnitTest {
+
+	/**
+	 * Returns the lines where errors should occur.
+	 *
+	 * @return array <int line number> => <int number of errors>
+	 */
+	public function getErrorList() {
+		return array(
+			12 => 1,
+			13 => 1,
+			14 => 1,
+			15 => 1,
+			24 => 1,
+			25 => 2,
+			26 => 1,
+			27 => 2,
+			28 => 1,
+			29 => 2,
+			30 => 2,
+			31 => 1,
+			32 => 1,
+			33 => 1,
+			34 => 1,
+			35 => 1,
+			38 => 1,
+			39 => 2,
+			40 => 1,
+			41 => 2,
+			42 => 1,
+			43 => 2,
+			44 => 2,
+			45 => 1,
+			46 => 1,
+			47 => 1,
+			48 => 1,
+			49 => 1,
+		);
+	}
+
+	/**
+	 * Returns the lines where warnings should occur.
+	 *
+	 * @return array <int line number> => <int number of warnings>
+	 */
+	public function getWarningList() {
+		return array(
+			18 => 1,
+			19 => 1,
+			// 20 => 1,
+			21 => 1,
+			34 => 1,
+			35 => 1,
+			48 => 1,
+			49 => 1,
+		);
+	}
+}