Pull all path splitting logic into a single method

Author: colinodell

src/Data.php

@@ -42,12 +42,8 @@ public function __construct(array $data = [])
      */
     public function append(string $key, $value = null): void
     {
-        if (0 == strlen($key)) {
-            throw new InvalidPathException("Key cannot be an empty string");
-        }
-
         $currentValue =& $this->data;
-        $keyPath = explode('.', $key);
+        $keyPath = $this->keyToPathArray($key);
 
         if (1 == count($keyPath)) {
             if (!isset($currentValue[$key])) {
@@ -88,12 +84,8 @@ public function append(string $key, $value = null): void
      */
     public function set(string $key, $value = null): void
     {
-        if (0 == strlen($key)) {
-            throw new InvalidPathException("Key cannot be an empty string");
-        }
-
         $currentValue =& $this->data;
-        $keyPath = explode('.', $key);
+        $keyPath = $this->keyToPathArray($key);
 
         if (1 == count($keyPath)) {
             $currentValue[$key] = $value;
@@ -120,12 +112,8 @@ public function set(string $key, $value = null): void
      */
     public function remove(string $key): void
     {
-        if (0 == strlen($key)) {
-            throw new InvalidPathException("Key cannot be an empty string");
-        }
-
         $currentValue =& $this->data;
-        $keyPath = explode('.', $key);
+        $keyPath = $this->keyToPathArray($key);
 
         if (1 == count($keyPath)) {
             unset($currentValue[$key]);
@@ -152,7 +140,7 @@ public function remove(string $key): void
     public function get(string $key, $default = null)
     {
         $currentValue = $this->data;
-        $keyPath = explode('.', $key);
+        $keyPath = $this->keyToPathArray($key);
 
         for ($i = 0; $i < count($keyPath); $i++) {
             $currentKey = $keyPath[$i];
@@ -176,7 +164,7 @@ public function get(string $key, $default = null)
     public function has(string $key): bool
     {
         $currentValue = &$this->data;
-        $keyPath = explode('.', $key);
+        $keyPath = $this->keyToPathArray($key);
 
         for ($i = 0; $i < count($keyPath); $i++) {
             $currentKey = $keyPath[$i];
@@ -266,4 +254,20 @@ public function offsetUnset($key)
     {
         $this->remove($key);
     }
+
+    /**
+     * @return string[]
+     *
+     * @psalm-return non-empty-list<string>
+     *
+     * @psalm-pure
+     */
+    protected function keyToPathArray(string $path): array
+    {
+        if (\strlen($path) === 0) {
+            throw new InvalidPathException('Path cannot be an empty string');
+        }
+
+        return \explode('.', $path);
+    }
 }

tests/DataTest.php

@@ -56,6 +56,9 @@ protected function runSampleDataTests(DataInterface $data)
         $this->assertNull($data->get('f.g.h.i'));
         $this->assertEquals($data->get('foo', 'default-value-1'), 'default-value-1', 'Return default value');
         $this->assertEquals($data->get('f.g.h.i', 'default-value-2'), 'default-value-2');
+
+        $this->expectException(InvalidPathException::class);
+        $data->get('', 'broken');
     }
 
     public function testAppend()
@@ -165,6 +168,9 @@ public function testHas()
         ) {
             $this->assertFalse($data->has($notExistentKey));
         }
+
+        $this->expectException(InvalidPathException::class);
+        $data->has('', 'broken');
     }
 
     public function testGetData()