feat: add sniff to enforce short echo tag on single-line echoing

InpsydeTemplates/Sniffs/Formatting/ShortEchoTagSniff.php

@@ -0,0 +1,99 @@
+<?php
+
+declare(strict_types=1);
+
+namespace InpsydeTemplates\Sniffs\Formatting;
+
+use PHP_CodeSniffer\Files\File;
+use PHP_CodeSniffer\Sniffs\Sniff;
+use PHP_CodeSniffer\Util\Tokens;
+
+/**
+ * @psalm-type Token = array{
+ *     type: string,
+ *     code: string|int,
+ *     line: int
+ *     }
+ */
+final class ShortEchoTagSniff implements Sniff
+{
+    /**
+     * @return list<int|string>
+     */
+    public function register(): array
+    {
+        return [
+            T_ECHO,
+        ];
+    }
+
+    /**
+     * @param File $phpcsFile
+     * @param int $stackPtr
+     *
+     * phpcs:disable Inpsyde.CodeQuality.ArgumentTypeDeclaration
+     */
+    public function process(File $phpcsFile, $stackPtr): void
+    {
+        // phpcs:enable Inpsyde.CodeQuality.ArgumentTypeDeclaration
+
+        /** @var array<int, Token> $tokens */
+        $tokens = $phpcsFile->getTokens();
+        $currentLine = $tokens[$stackPtr]['line'];
+
+        $prevPtr = $phpcsFile->findPrevious(
+            Tokens::$emptyTokens,
+            ($stackPtr - 1),
+            null,
+            true
+        );
+
+        if (!is_int($prevPtr) || !isset($tokens[$prevPtr])) {
+            return;
+        }
+
+        $prevToken = $tokens[$prevPtr];
+
+        if ($prevToken['line'] !== $currentLine) {
+            return;
+        }
+
+        if ($prevToken['code'] !== T_OPEN_TAG) {
+            return;
+        }
+
+        $closeTagPtr = $phpcsFile->findNext(
+            T_CLOSE_TAG,
+            ($stackPtr + 1),
+        );
+
+        if (
+            !is_int($closeTagPtr)
+            || !isset($tokens[$closeTagPtr])
+            || $tokens[$closeTagPtr]['line'] !== $currentLine
+        ) {
+            return;
+        }
+
+        $message = sprintf(
+            'Single line output on line %d'
+            . ' should use short echo tag `<?= ` instead of `<?php echo`.',
+            $currentLine
+        );
+
+        if ($phpcsFile->addFixableWarning($message, $stackPtr, 'Encouraged')) {
+            $this->fix($prevPtr, $stackPtr, $phpcsFile);
+        }
+    }
+
+    private function fix(int $openTagPtr, int $echoPtr, File $file): void
+    {
+        $fixer = $file->fixer;
+        $fixer->beginChangeset();
+
+        $fixer->replaceToken($echoPtr, '');
+        $fixer->replaceToken($openTagPtr, '<?=');
+
+        $fixer->endChangeset();
+    }
+}

tests/unit/fixtures/short-echo-tag.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+// @phpcsSniff InpsydeTemplates.Formatting.ShortEchoTag
+
+echo 'content';
+
+echo 'content', 'yet another';
+
+echo ('content'), 'yet';
+
+echo htmlentities('content');
+
+echo $GLOBALS['flag'] ? 'yes' : 'no'; echo 'maybe', 'no'; ?>
+
+<?php echo 'content';
+echo 'no' ?>
+
+<?php echo 'content' // @phpcsWarningOnThisLine ?>
+
+<?php echo 'content', 'yet another'; // @phpcsWarningOnThisLine ?>
+
+<?php echo ('content'), 'yet'; // @phpcsWarningOnThisLine ?>
+
+<?php echo htmlentities('content') // @phpcsWarningOnThisLine ?>
+
+<?php echo $GLOBALS['flag'] ? 'yes' : 'no'; echo 'maybe', 'no'; // @phpcsWarningOnThisLine ?>