diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..c9dc060
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,14 @@
+# This is the top-most .editorconfig file; do not search in parent directories.
+root = true
+
+# All files.
+[*]
+end_of_line = LF
+indent_style = space
+indent_size = 4
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[Makefile]
+indent_style = tab
diff --git a/.gitignore b/.gitignore
index 8b7ef35..612c601 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /vendor
 composer.lock
+.phpunit.result.cache
diff --git a/composer.json b/composer.json
index ec33283..6e2632d 100644
--- a/composer.json
+++ b/composer.json
@@ -9,11 +9,21 @@
         "doctrine/orm": "^2.12",
         "symfony/framework-bundle": "*"
     },
+    "require-dev": {
+        "vimeo/psalm": "^4.24",
+        "psalm/plugin-symfony": "^3.1",
+        "phpunit/phpunit": "^9.5"
+    },
     "autoload": {
         "psr-4": {
             "Pcm\\SearchBundle\\": "src/"
         }
-    },  
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Pcm\\SearchBundle\\": "tests/"
+        }
+    },
     "authors": [
         {
             "name": "Matt Feeny",
@@ -23,9 +33,5 @@
             "name": "Bradley Goode",
             "email": "bg@pcmsystems.co.uk"
         }
-    ],
-    "require-dev": {
-        "vimeo/psalm": "^4.24",
-        "psalm/plugin-symfony": "^3.1"
-    }
+    ]
 }
diff --git a/config/services.yaml b/config/services.yaml
new file mode 100644
index 0000000..6655f73
--- /dev/null
+++ b/config/services.yaml
@@ -0,0 +1,4 @@
+services:
+    Pcm\SearchBundle\EventSubscriber\SearchableSubscriber:
+        tags:
+            - { name: doctrine.event_subscriber }
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..e8f8e0c
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit colors="true" bootstrap="vendor/autoload.php">
+    <testsuites>
+        <testsuite name="Test Suite">
+            <directory suffix="Test.php">./tests/</directory>
+        </testsuite>
+    </testsuites>
+    <filter>
+        <whitelist>
+            <directory>./src</directory>
+        </whitelist>
+    </filter>
+</phpunit>
diff --git a/src/Service/SearchService.php b/src/Service/SearchService.php
index 92e8727..f37a49d 100644
--- a/src/Service/SearchService.php
+++ b/src/Service/SearchService.php
@@ -14,7 +14,14 @@ class SearchService
 {
     public function __construct(private EntityManagerInterface $em) {}
 
-    public function index($entity)
+    /**
+     * Given an $entity that implements SearchableInterface, this method
+     * creates or updates a SearchIndex $entity
+     *
+     * @param SearchableInterface $entity
+     * @return void
+     */
+    public function index(SearchableInterface $entity)
     {
         $searchIndex = $this->createSearchResult($entity);
 
@@ -22,7 +29,14 @@ class SearchService
         $this->em->flush();
     }
 
-    public function unIndex($entity)
+    /**
+     * Given an $entity that implements SearchableInterface, this method removes
+     * the item from the search index
+     *
+     * @param SearchableInterface $entity
+     * @return void
+     */
+    public function unIndex(SearchableInterface $entity)
     {
         $class = get_class($entity);
 
@@ -37,6 +51,14 @@ class SearchService
         }
     }
 
+    /**
+     * Given an entity that implements SearchableInterface, this method first checks
+     * if the relevant SearchIndex entity exists. If it doesn't, it's created. The
+     * title and index data are set based on the methods in the $entity
+     *
+     * @param SearchableInterface $entity
+     * @return SearchIndex
+     */
     public function createSearchResult(SearchableInterface $entity): SearchIndex
     {
         $values = [];
@@ -76,7 +98,8 @@ class SearchService
     }
 
     /**
-     * Finds all searchable Doctrine entities.
+     * Finds all searchable Doctrine entities the implement SearchableInterface
+     * @return array
      */
     public function getSearchableClasses(): array
     {
diff --git a/tests/.gitkeep b/tests/.gitkeep
new file mode 100644
index 0000000..e69de29