feat(detection) Detect symbol of kind abc\{def\ghi, klm\nop}. (#27)

This patch updates `getImportedSymbolsFromGroupStatement` to
understand namespaced symbols (`x\y`) inside a group (`{…}`), like
`abc\{def\ghi, klm\nop}`.

This patch also adds, for the sake of completeness, an alias property
on `Symbol`, so that not only the last strings of a namespaced name is
considered as an alias, but the real alias string (`as x`, here `x`)
can be used as an alias if declared.

Author: Hywan

ImportDetection/SniffHelpers.php

@@ -92,23 +92,40 @@ private function getImportedSymbolsFromGroupStatement(File $phpcsFile, int $stac
 		}
 
 		// Get the namespace for the import first, so we can attach it to each Symbol
-		$importNamespace = $this->getFullSymbol($phpcsFile, $startBracketPtr - 1);
+		$importPrefixSymbol = $this->getFullSymbol($phpcsFile, $startBracketPtr - 1);
 
 		$collectedSymbols = [];
 		$lastStringPtr = $startBracketPtr;
+
 		while ($lastStringPtr < $endBracketPtr) {
-			$nextStringPtr = $phpcsFile->findNext([T_STRING], $lastStringPtr + 1, $endBracketPtr);
-			if (! $nextStringPtr || ! isset($tokens[$nextStringPtr])) {
-				break;
+			$commaPtr = $phpcsFile->findNext([T_COMMA], $lastStringPtr + 1, $endBracketPtr) ?: $endBracketPtr;
+			$aliasPtr = $phpcsFile->findNext([T_AS], $lastStringPtr + 1, $commaPtr);
+			$aliasSymbol = null;
+
+			if ($aliasPtr) {
+				$aliasStringPtr = $phpcsFile->findNext([T_STRING], $aliasPtr + 1, $commaPtr);
+				$aliasSymbol = new Symbol([Symbol::getTokenWithPosition($tokens[$aliasStringPtr], $aliasStringPtr)]);
 			}
-			$nextCommaPtr = $phpcsFile->findNext([T_COMMA], $nextStringPtr + 1, $endBracketPtr) ?: $endBracketPtr;
-			$nextAliasPtr = $phpcsFile->findNext([T_AS], $nextStringPtr + 1, $nextCommaPtr);
-			if (! $nextAliasPtr) {
-				$fullSymbolParts = array_merge($importNamespace->getTokens(), [Symbol::getTokenWithPosition($tokens[$nextStringPtr], $nextStringPtr)]);
-				$collectedSymbols[] = new Symbol($fullSymbolParts);
+
+			$endOfStringsPtr = $aliasPtr ?: $commaPtr;
+			$importSuffixSymbols = [];
+
+			do {
+				$lastStringPtr = $phpcsFile->findNext([T_STRING, T_NS_SEPARATOR], $lastStringPtr + 1, $endOfStringsPtr);
+
+				if ($lastStringPtr) {
+					$importSuffixSymbols[] = Symbol::getTokenWithPosition($tokens[$lastStringPtr], $lastStringPtr);
+				}
+			} while ($lastStringPtr);
+
+			$lastStringPtr = $commaPtr;
+
+			if (! empty($importSuffixSymbols)) {
+				$importCompleteSymbol = array_merge($importPrefixSymbol->getTokens(), $importSuffixSymbols);
+				$collectedSymbols[] = new Symbol($importCompleteSymbol, $aliasSymbol);
 			}
-			$lastStringPtr = $nextStringPtr;
 		}
+
 		return $collectedSymbols;
 	}
 

ImportDetection/Symbol.php

@@ -6,8 +6,9 @@
 class Symbol {
 	private $tokens;
 	private $isUsed;
+	private $alias;
 
-	public function __construct(array $tokens) {
+	public function __construct(array $tokens, self $alias = null) {
 		if (empty($tokens)) {
 			throw new \Exception('Cannot construct Symbol with no tokens');
 		}
@@ -18,6 +19,7 @@ public function __construct(array $tokens) {
 		}
 		$this->tokens = $tokens;
 		$this->isUsed = false;
+		$this->alias = $alias;
 	}
 
 	public static function getTokenWithPosition(array $token, int $stackPtr): array {
@@ -34,6 +36,10 @@ public function getName(): string {
 	}
 
 	public function getAlias(): string {
+		if ($this->alias) {
+			return $this->alias->getName();
+		}
+
 		return $this->tokens[count($this->tokens) - 1]['content'];
 	}
 

tests/Sniffs/Imports/ClassFixtures.php

@@ -0,0 +1,15 @@
+<?php
+use NamespaceName\{
+	A, // used line 13
+	C\D, // not used
+	X\Y as Z, // used line 14
+};
+use NamespaceName\{
+	B, // not used
+	E\F, // used line 15
+	I\J as H, // not used
+};
+
+A::class;
+Z::class;
+F::class;

tests/Sniffs/Imports/RequireImportsSniffTest.php

@@ -323,6 +323,33 @@ public function testRequireImportsFindsUnimportedNamespaceIdenticalToClass() {
 		$this->assertEquals($expectedLines, $lines);
 	}
 
+	public function testRequireImportsNoticesUnusedClasses() {
+		$fixtureFile = __DIR__ . '/ClassFixtures.php';
+		$sniffFile = __DIR__ . '/../../../ImportDetection/Sniffs/Imports/RequireImportsSniff.php';
+		$helper = new SniffTestHelper();
+		$phpcsFile = $helper->prepareLocalFileForSniffs($sniffFile, $fixtureFile);
+		$phpcsFile->process();
+
+		$warnings = $phpcsFile->getWarnings();
+		$messages = $helper->getWarningMessageRecords($warnings);
+		$messages = array_values(array_filter($messages, function ($message) {
+			return $message->source === 'ImportDetection.Imports.RequireImports.Import';
+		}));
+		$lines = array_map(function ($message) {
+			return $message->rowNumber;
+		}, $messages);
+		$expectedLines = [
+			2,
+			7,
+			7,
+		];
+		$this->assertEquals($expectedLines, $lines);
+		$this->assertCount(3, $messages);
+		$this->assertEquals('Found unused symbol \'NamespaceName\C\D\'.', $messages[0]->message);
+		$this->assertEquals('Found unused symbol \'NamespaceName\B\'.', $messages[1]->message);
+		$this->assertEquals('Found unused symbol \'NamespaceName\I\J\'.', $messages[2]->message);
+	}
+
 	public function testRequireImportsNoticesUnusedConstants() {
 		$fixtureFile = __DIR__ . '/ConstantsFixure.php';
 		$sniffFile = __DIR__ . '/../../../ImportDetection/Sniffs/Imports/RequireImportsSniff.php';