The json_encode($json, \JSON_PRETTY_PRINT) call to generate the cURL version of a HTTP Request in HttpClientDataCollector didn't use the self::jsonEncode method available.

The main issue with that is the usage of \JSON_PRETTY_PRINT, which is overwrites all other flags in self::jsonEncode method, especially \JSON_PRESERVE_ZERO_FRACTION.

So I have added a test for it:

1) Symfony\Component\HttpClient\Tests\DataCollector\HttpClientDataCollectorTest::testItGeneratesCurlCommandsAsExpected with data set "POST with json" (array('POST', 'http://localhost:8057/js
on', array(array(array('baz', array(1.1, 1.0))))), 'curl \\n  --compressed \\n  -...n}%1$s')
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
         "bar": "baz",\n
         "qux": [\n
             1.1,\n
-            1.0\n
+            1\n
         ]\n
     }\n
 }''

After the changes, this test pass ✅

I've added test for all other flags, to be sure that they are used. It could lead to less readable JSON (with hex values) displayed in Profiler, but it's more accurate to debug.

EDIT: removing \JSON_PRETTY_PRINT solve the problem too, and we don't need to pretty-print the JSON in curl command, it allows to run the exact same request.