Add cywise_truncate_string helper and use it in RemoteAction to limit large JSON output

Author: csavelief

app/AgentSquad/Actions/RemoteAction.php

@@ -161,15 +161,15 @@ public function body(): string
             return new FailedAnswer("Remote action call failed for action {$this->name()}", $chainOfThought);
         }
 
-        $chainOfThought[] = new ThoughtActionObservation("Call the remote action {$this->name()} endpoint.", "call[{$action->url}]", "The endpoint has been called and the call succeeded: " . json_encode($data));
+        $chainOfThought[] = new ThoughtActionObservation("Call the remote action {$this->name()} endpoint.", "call[{$action->url}]", "The endpoint has been called and the call succeeded: " . cywise_truncate_string(json_encode($data)));
 
         // Build the response
         if (empty($action->response_template)) {
             $transformation = $data;
-            $chainOfThought[] = new ThoughtActionObservation("Return data from action {$this->name()} as-is.", "transform[" . json_encode($data) . "]", "The data have not been transformed: " . json_encode($transformation));
+            $chainOfThought[] = new ThoughtActionObservation("Return data from action {$this->name()} as-is.", "transform[" . cywise_truncate_string(json_encode($data)) . "]", "The data have not been transformed: " . json_encode($transformation));
         } else {
             $transformation = $this->buildResponse($action->response_template, $payload['params'], $data);
-            $chainOfThought[] = new ThoughtActionObservation("Return data from action {$this->name()} after transformation.", "transform[" . json_encode($data) . "]", "The data have been transformed: {$transformation}");
+            $chainOfThought[] = new ThoughtActionObservation("Return data from action {$this->name()} after transformation.", "transform[" . cywise_truncate_string(json_encode($data)) . "]", "The data have been transformed: {$transformation}");
         }
         return new SuccessfulAnswer(
             is_string($transformation) ? $transformation : json_encode($transformation),

app/Helpers/Helpers.php

@@ -358,4 +358,14 @@ function app_config_override(): array
         }
     }
 }
-
+if (!function_exists('cywise_truncate_string')) {
+    function cywise_truncate_string(string $str, int $size = 500): string
+    {
+        if (mb_strlen($str) <= $size) {
+            return $str;
+        }
+        $start = mb_substr($str, 0, 50);
+        $end = mb_substr($str, -50);
+        return $start . '[...]' . $end;
+    }
+}

tests/Unit/WithoutDb/HelpersTest.php

@@ -167,3 +167,56 @@
         "[END 2x REPEATED LINE]",
     ]);
 });
+
+test('truncate string shorter than limit', function () {
+    $str = 'Short string';
+    expect(cywise_truncate_string($str, 50))->toEqual($str);
+});
+
+test('truncate string equal to limit', function () {
+    $str = str_repeat('a', 100);
+    expect(cywise_truncate_string($str, 100))->toEqual($str);
+});
+
+test('truncate string longer than limit', function () {
+
+    $start = str_repeat('a', 50);
+    $middle = str_repeat('b', 10);
+    $end = str_repeat('c', 50);
+    $str = $start . $middle . $end;
+
+    // Total length is 110, limit is 100
+    $expected = $start . '[...]' . $end;
+    expect(cywise_truncate_string($str, 100))->toEqual($expected);
+});
+
+test('truncate string with default limit (500)', function () {
+    $str = str_repeat('a', 501);
+    $expected = str_repeat('a', 50) . '[...]' . str_repeat('a', 50);
+    expect(cywise_truncate_string($str))->toEqual($expected);
+});
+
+test('truncate string with multibyte characters', function () {
+
+    $start = str_repeat('é', 50);
+    $middle = '🚀';
+    $end = str_repeat('à', 50);
+    $str = $start . $middle . $end;
+
+    // Total mb_length is 101, limit is 100
+    $expected = $start . '[...]' . $end;
+    expect(cywise_truncate_string($str, 100))->toEqual($expected);
+});
+
+test('truncate string with very short string but limit smaller than 100', function () {
+
+    $str = "This is a string that is longer than ten characters."; // 52 chars
+    $limit = 10;
+
+    // Since length (52) > limit (10), it will take first 50 and last 50.
+    $start = mb_substr($str, 0, 50);
+    $end = mb_substr($str, -50);
+    $expected = $start . '[...]' . $end;
+
+    expect(cywise_truncate_string($str, $limit))->toEqual($expected);
+});