Fixing Fixer error messages

src/Service/Fixer.php

@@ -94,7 +94,7 @@ private function createRate($url, CurrencyPair $currencyPair)
         $data = StringUtil::jsonToArray($content);
 
         if (isset($data['error'])) {
-            throw new Exception($data['error']);
+            throw new Exception($this->getErrorMessage($data['error']['code']));
         }
 
         if (isset($data['rates'][$currencyPair->getQuoteCurrency()])) {
@@ -106,4 +106,36 @@ private function createRate($url, CurrencyPair $currencyPair)
 
         return null;
     }
+
+    /**
+     * Gets the error message corresponding to the error code.
+     *
+     * @param string $code The error code
+     *
+     * @return string
+     */
+    private function getErrorMessage($code)
+    {
+        $errors = [
+            404 => 'The requested resource does not exist.',
+            101 => 'No API Key was specified or an invalid API Key was specified.',
+            103 => 'The requested API endpoint does not exist.',
+            104 => 'The maximum allowed API amount of monthly API requests has been reached.',
+            105 => 'The current subscription plan does not support this API endpoint.',
+            106 => 'The current request did not return any results.',
+            102 => 'The account this API request is coming from is inactive.',
+            201 => 'An invalid base currency has been entered.',
+            202 => 'One or more invalid symbols have been specified.',
+            301 => 'No date has been specified.',
+            302 => 'An invalid date has been specified.',
+            403 => 'No or an invalid amount has been specified.',
+            501 => 'No or an invalid timeframe has been specified.',
+            502 => 'No or an invalid "start_date" has been specified.',
+            503 => 'No or an invalid "end_date" has been specified.',
+            504 => 'An invalid timeframe has been specified.',
+            505 => 'The specified timeframe is too long, exceeding 365 days.',
+        ];
+
+        return isset($errors[$code]) ? $errors[$code] : '';
+    }
 }

tests/Fixtures/Service/Fixer/error.json

@@ -1,3 +1,7 @@
 {
-  "error": "Invalid base"
+    "success": false,
+    "error": {
+        "code": 105,
+        "type": "base_currency_access_restricted"
+    }
 }

tests/Tests/Service/FixerTest.php

@@ -31,6 +31,7 @@ public function it_supports_all_queries()
     /**
      * @test
      * @expectedException \Exchanger\Exception\Exception
+     * @expectedExceptionMessage The current subscription plan does not support this API endpoint.
      */
     public function it_throws_an_exception_with_error_response()
     {