Compacted and added cycle visualization.

Author: fhein

src/Exception/CyclicAliasException.php

@@ -7,141 +7,28 @@
 
 namespace Zend\ServiceManager\Exception;
 
-use function array_filter;
-use function array_keys;
-use function array_map;
-use function array_values;
-use function implode;
-use function reset;
-use function serialize;
-use function sort;
 use function sprintf;
 
 class CyclicAliasException extends InvalidArgumentException
 {
     /**
+     * @param string   conflicting alias key
      * @param string[] $aliases map of referenced services, indexed by alias name (string)
      *
      * @return self
      */
-    public static function fromAliasesMap(array $aliases)
+    public static function fromCyclicAlias($alias, $aliases)
     {
-        $detectedCycles = array_filter(array_map(
-            function ($alias) use ($aliases) {
-                return self::getCycleFor($aliases, $alias);
-            },
-            array_keys($aliases)
-        ));
-
-        if (! $detectedCycles) {
-            return new self(sprintf(
-                "A cycle was detected within the following aliases map:\n\n%s",
-                self::printReferencesMap($aliases)
-            ));
+        $msg = $alias;
+        $cursor = $alias;
+        while($aliases[$cursor] !== $alias) {
+            $cursor = $aliases[$cursor];
+            $msg .= ' -> '. $cursor;
         }
-
+        $msg .= ' -> ' . $alias . PHP_EOL;
         return new self(sprintf(
-            "Cycles were detected within the provided aliases:\n\n%s\n\n"
-            . "The cycle was detected in the following alias map:\n\n%s",
-            self::printCycles(self::deDuplicateDetectedCycles($detectedCycles)),
-            self::printReferencesMap($aliases)
-        ));
-    }
-
-    /**
-     * Retrieves the cycle detected for the given $alias, or `null` if no cycle was detected
-     *
-     * @param string[] $aliases
-     * @param string   $alias
-     *
-     * @return array|null
-     */
-    private static function getCycleFor(array $aliases, $alias)
-    {
-        $cycleCandidate = [];
-        $targetName     = $alias;
-
-        while (isset($aliases[$targetName])) {
-            if (isset($cycleCandidate[$targetName])) {
-                return $cycleCandidate;
-            }
-
-            $cycleCandidate[$targetName] = true;
-
-            $targetName = $aliases[$targetName];
-        }
-
-        return null;
-    }
-
-    /**
-     * @param string[] $aliases
-     *
-     * @return string
-     */
-    private static function printReferencesMap(array $aliases)
-    {
-        $map = [];
-
-        foreach ($aliases as $alias => $reference) {
-            $map[] = '"' . $alias . '" => "' . $reference . '"';
-        }
-
-        return "[\n" . implode("\n", $map) . "\n]";
-    }
-
-    /**
-     * @param string[][] $detectedCycles
-     *
-     * @return string
-     */
-    private static function printCycles(array $detectedCycles)
-    {
-        return "[\n" . implode("\n", array_map([__CLASS__, 'printCycle'], $detectedCycles)) . "\n]";
-    }
-
-    /**
-     * @param string[] $detectedCycle
-     *
-     * @return string
-     */
-    private static function printCycle(array $detectedCycle)
-    {
-        $fullCycle   = array_keys($detectedCycle);
-        $fullCycle[] = reset($fullCycle);
-
-        return implode(
-            ' => ',
-            array_map(
-                function ($cycle) {
-                    return '"' . $cycle . '"';
-                },
-                $fullCycle
-            )
-        );
-    }
-
-    /**
-     * @param bool[][] $detectedCycles
-     *
-     * @return bool[][] de-duplicated
-     */
-    private static function deDuplicateDetectedCycles(array $detectedCycles)
-    {
-        $detectedCyclesByHash = [];
-
-        foreach ($detectedCycles as $detectedCycle) {
-            $cycleAliases = array_keys($detectedCycle);
-
-            sort($cycleAliases);
-
-            $hash = serialize(array_values($cycleAliases));
-
-            $detectedCyclesByHash[$hash] = isset($detectedCyclesByHash[$hash])
-                ? $detectedCyclesByHash[$hash]
-                : $detectedCycle;
-        }
-
-        return array_values($detectedCyclesByHash);
+            "A cycle was detected within the aliases defintions:\n%s",
+            $msg
+            ));
     }
 }