Use ?string instead of false|string

Author: JulianVennen

src/Storage/EtcdStorage.php

@@ -17,31 +17,37 @@ public function __construct(?ClientInterface $client = null)
         $this->client = $client ?? new Client();
     }
 
-    public function putIf(string $key, string $value, bool|string $previousValue, bool $returnNewValueOnFail): bool|string
+    public function putIf(string $key, string $value, ?string $previousValue, bool $returnNewValueOnFail): bool|string
     {
         try {
-            return $this->client->putIf($key, $value, $previousValue, $returnNewValueOnFail);
+            return $this->client->putIf($key, $value, $previousValue ?? false, $returnNewValueOnFail);
         } catch (UnavailableException | DeadlineExceededException | UnknownException $e) {
             throw new StorageException($e->getMessage(), $e->getCode(), $e);
         }
     }
 
-    public function deleteIf(string $key, $previousValue, bool $returnNewValueOnFail = false): bool|string
+    public function deleteIf(string $key, ?string $previousValue, bool $returnNewValueOnFail = false): bool|string
     {
         try {
-            return $this->client->deleteIf($key, $previousValue, $returnNewValueOnFail);
+            return $this->client->deleteIf($key, $previousValue ?? false, $returnNewValueOnFail);
         } catch (UnavailableException | DeadlineExceededException | UnknownException $e) {
             throw new StorageException($e->getMessage(), $e->getCode(), $e);
         }
     }
 
 
-    public function get(string $key): bool|string
+    public function get(string $key): ?string
     {
         try {
-            return $this->client->get($key);
+            $value = $this->client->get($key);
         } catch (UnavailableException | DeadlineExceededException | UnknownException $e) {
             throw new StorageException($e->getMessage(), $e->getCode(), $e);
         }
+
+        if ($value === false) {
+            return null;
+        }
+
+        return $value;
     }
 }

src/Storage/StorageInterface.php

@@ -10,35 +10,40 @@
 interface StorageInterface
 {
     /**
-     * Put `$value` if `$key` value matches `$previousValue` otherwise `$returnNewValueOnFail`
+     * Put `$value` if `$key` value matches `$previousValue` and return true. If the new value does not match and
+     * `$returnNewValueOnFail` is true return the new value, otherwise return false.
      * @param string $key
      * @param string $value The new value to set
-     * @param bool|string $previousValue The previous value to compare against
-     * @param bool $returnNewValueOnFail
-     * @return bool|string
+     * @param string|null $previousValue The previous value to compare against. If null is provided, the comparison
+     * should check that the key does not exist yet.
+     * @param bool $returnNewValueOnFail if true the new value of the key should be returned if the operation fails
+     * @return bool|string true if the operation succeeded, false if it failed and `$returnNewValueOnFail` is false,
+     * otherwise the new value of the key
      * @throws StorageException a known, retryable error occurred
      * @throws Exception an unknown error occurred
      */
-    public function putIf(string $key, string $value, bool|string $previousValue, bool $returnNewValueOnFail): bool|string;
+    public function putIf(string $key, string $value, ?string $previousValue, bool $returnNewValueOnFail): bool|string;
 
     /**
      * Delete if $key value matches $previous value otherwise $returnNewValueOnFail
      *
      * @param string $key
-     * @param bool|string $previousValue The previous value to compare against
+     * @param string|null $previousValue The previous value to compare against. If null is provided, the comparison
+     *  should check that the key does not exist yet.
      * @param bool $returnNewValueOnFail
-     * @return bool|string
+     * @return bool|string true if the operation succeeded, false if it failed and `$returnNewValueOnFail` is false,
+     * otherwise the new value of the key
      * @throws StorageException a known, retryable error occurred
      * @throws Exception an unknown error occurred
      */
-    public function deleteIf(string $key, bool|string $previousValue, bool $returnNewValueOnFail = false): bool|string;
+    public function deleteIf(string $key, ?string $previousValue, bool $returnNewValueOnFail = false): bool|string;
 
     /**
      * Get the value of a key
      * @param string $key
-     * @return bool|string
+     * @return string|null the value of the key or null if the key does not exist
      * @throws StorageException a known, retryable error occurred
      * @throws Exception an unknown error occurred
      */
-    public function get(string $key): bool|string;
+    public function get(string $key): ?string;
 }