Support alias commands

Author: Ethan Hann

docs-src/indexing.md

@@ -170,7 +170,7 @@ $bookIndex->addMany($documents);
 $bookIndex->addMany($documents, true);
 ```
 
-## Indexing from a Hash
+## Indexing From a Hash
 
 Redis hashes are key/value pairs referenced by a key. 
 It is possible to index an existing hash with the **addHash** method.
@@ -189,4 +189,40 @@ Replace a document in the index from a hash:
 ```php
 $document = $bookIndex->makeDocument('foo');
 $bookIndex->replaceHash($document);
-```
+```
+
+## Aliasing
+
+Indexes can be aliased.
+ 
+Note that an exception will be thrown if any alias method is called before an index's [schema](/#create-the-schema) is created.  
+
+### Adding an Alias
+
+An alias can be added for an index like this:
+
+```php-inline
+$index->addAlias('foo');
+```
+
+### Updating an Alias
+
+Assuming an alias has already been added to an index, like this:
+
+```php-inline
+$oldIndex->addAlias('foo');
+```
+
+...it can be reassigned to a different index like this:
+
+```php-inline
+$newIndex->updateAlias('foo');
+```
+
+### Deleting an Alias
+
+An alias can be deleted like this:
+
+```php-inline
+$index->deleteAlias('foo');
+```

src/Exceptions/AliasDoesNotExistException.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Ehann\RediSearch\Exceptions;
+
+use Exception;
+
+class AliasDoesNotExistException extends Exception
+{
+    public function __construct($message = '', $code = 0, Exception $previous = null)
+    {
+        parent::__construct(
+            trim("Alias does not exist. $message"),
+            $code,
+            $previous
+        );
+    }
+}

src/Exceptions/UnknownIndexNameOrNameIsAnAliasItselfException.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Ehann\RediSearch\Exceptions;
+
+use Exception;
+
+class UnknownIndexNameOrNameIsAnAliasItselfException extends Exception
+{
+    public function __construct($message = '', $code = 0, Exception $previous = null)
+    {
+        parent::__construct(
+            trim("Unknown index name (or name is an alias itself). $message"),
+            $code,
+            $previous
+        );
+    }
+}

src/Index.php

@@ -593,4 +593,31 @@ public function count(string $query = ''): int
     {
         return $this->makeQueryBuilder()->count($query);
     }
+
+    /**
+     * @param string $name
+     * @return bool
+     */
+    public function addAlias(string $name): bool
+    {
+        return $this->rawCommand('FT.ALIASADD', [$name, $this->getIndexName()]);
+    }
+
+    /**
+     * @param string $name
+     * @return bool
+     */
+    public function updateAlias(string $name): bool
+    {
+        return $this->rawCommand('FT.ALIASUPDATE', [$name, $this->getIndexName()]);
+    }
+
+    /**
+     * @param string $name
+     * @return bool
+     */
+    public function deleteAlias(string $name): bool
+    {
+        return $this->rawCommand('FT.ALIASDEL', [$name]);
+    }
 }

src/IndexInterface.php

@@ -34,4 +34,7 @@ public function addMany(array $documents, $disableAtomicity = false);
     public function replace($document): bool;
     public function addHash($document): bool;
     public function replaceHash($document): bool;
+    public function addAlias(string $name): bool;
+    public function updateAlias(string $name): bool;
+    public function deleteAlias(string $name): bool;
 }

src/RediSearchRedisClient.php

@@ -2,8 +2,10 @@
 
 namespace Ehann\RediSearch;
 
+use Ehann\RediSearch\Exceptions\AliasDoesNotExistException;
 use Ehann\RediSearch\Exceptions\RediSearchException;
 use Ehann\RediSearch\Exceptions\UnknownIndexNameException;
+use Ehann\RediSearch\Exceptions\UnknownIndexNameOrNameIsAnAliasItselfException;
 use Ehann\RediSearch\Exceptions\UnknownRediSearchCommandException;
 use Ehann\RediSearch\Exceptions\UnsupportedRediSearchLanguageException;
 use Ehann\RedisRaw\AbstractRedisRawClient;
@@ -39,6 +41,15 @@ public function validateRawCommandResults($payload)
         if (in_array($message, ['unsupported language', 'unsupported stemmer language', 'bad argument for `language`'])) {
             throw new UnsupportedRediSearchLanguageException();
         }
+
+        if ($message === 'unknown index name (or name is an alias itself)') {
+            throw new UnknownIndexNameOrNameIsAnAliasItselfException();
+        }
+
+        if ($message === 'alias does not exist') {
+            throw new AliasDoesNotExistException();
+        }
+
         if (strpos($message, 'err unknown command \'ft.') !== false) {
             throw new UnknownRediSearchCommandException($message);
         }

tests/RediSearch/IndexTest.php

@@ -2,9 +2,11 @@
 
 namespace Ehann\Tests\RediSearch;
 
+use Ehann\RediSearch\Exceptions\AliasDoesNotExistException;
 use Ehann\RediSearch\Exceptions\FieldNotInSchemaException;
 use Ehann\RediSearch\Exceptions\NoFieldsInIndexException;
 use Ehann\RediSearch\Exceptions\RediSearchException;
+use Ehann\RediSearch\Exceptions\UnknownIndexNameOrNameIsAnAliasItselfException;
 use Ehann\RediSearch\Fields\Tag;
 use Ehann\RediSearch\Fields\TagField;
 use Ehann\RediSearch\Index;
@@ -689,4 +691,57 @@ public function testShouldNotChangeOriginalSchemaFieldWhenAddingNewDocument()
         $this->assertEquals($expectedId, $documents[0]->getId());
         $this->assertEquals($expectedTitle, $documents[0]->title->getValue());
     }
+
+    public function testShouldCreateAlias()
+    {
+        $this->subject->create();
+
+        $result = $this->subject->addAlias('MyAlias');
+
+        $this->assertTrue($result);
+    }
+
+    public function testShouldUpdateAlias()
+    {
+        $this->subject->create();
+        $this->subject->addAlias('MyAlias');
+        $index = (new Index($this->redisClient, 'Second'))
+            ->addTextField('foo');
+        $index->create();
+
+        $result = $index->updateAlias('MyAlias');
+
+        $this->assertTrue($result);
+    }
+
+    public function testShouldDeleteAlias()
+    {
+        $this->subject->create();
+        $this->subject->addAlias('MyAlias');
+
+        $result = $this->subject->deleteAlias('MyAlias');
+
+        $this->assertTrue($result);
+    }
+
+    public function testShouldFailToCreateAliasIfIndexDoesNotExist()
+    {
+        $this->expectException(UnknownIndexNameOrNameIsAnAliasItselfException::class);
+
+        $this->subject->addAlias('MyAlias');
+    }
+
+    public function testShouldFailToUpdateAliasIfIndexDoesNotExist()
+    {
+        $this->expectException(UnknownIndexNameOrNameIsAnAliasItselfException::class);
+
+        $this->subject->updateAlias('MyAlias');
+    }
+
+    public function testShouldFailToDeleteAliasIfIndexDoesNotExist()
+    {
+        $this->expectException(AliasDoesNotExistException::class);
+
+        $this->subject->deleteAlias('MyAlias');
+    }
 }