Check for multiple body extractors in debug_handler (#1036)

* Check for multiple body extractors in `debug_handler`

* changelog link

axum-macros/tests/debug_handler/fail/multiple_body_extractors.rs

@@ -0,0 +1,7 @@
+use axum_macros::debug_handler;
+use axum::body::Bytes;
+
+#[debug_handler]
+async fn handler(_: String, _: Bytes) {}
+
+fn main() {}

axum-macros/tests/debug_handler/fail/multiple_body_extractors.stderr

@@ -0,0 +1,11 @@
+error: Only one body extractor can be applied
+ --> tests/debug_handler/fail/multiple_body_extractors.rs:5:18
+  |
+5 | async fn handler(_: String, _: Bytes) {}
+  |                  ^^^^^^^^^
+
+error: Only one body extractor can be applied
+ --> tests/debug_handler/fail/multiple_body_extractors.rs:5:29
+  |
+5 | async fn handler(_: String, _: Bytes) {}
+  |                             ^^^^^^^^

axum-macros/tests/debug_handler/fail/too_many_extractors.rs

@@ -1,24 +1,25 @@
 use axum_macros::debug_handler;
+use axum::http::Uri;
 
 #[debug_handler]
 async fn handler(
-    e1: String,
-    e2: String,
-    e3: String,
-    e4: String,
-    e5: String,
-    e6: String,
-    e7: String,
-    e8: String,
-    e9: String,
-    e10: String,
-    e11: String,
-    e12: String,
-    e13: String,
-    e14: String,
-    e15: String,
-    e16: String,
-    e17: String,
+    e1: Uri,
+    e2: Uri,
+    e3: Uri,
+    e4: Uri,
+    e5: Uri,
+    e6: Uri,
+    e7: Uri,
+    e8: Uri,
+    e9: Uri,
+    e10: Uri,
+    e11: Uri,
+    e12: Uri,
+    e13: Uri,
+    e14: Uri,
+    e15: Uri,
+    e16: Uri,
+    e17: Uri,
 ) {}
 
 fn main() {}

axum-macros/tests/debug_handler/fail/too_many_extractors.stderr

@@ -1,11 +1,11 @@
 error: Handlers cannot take more than 16 arguments. Use `(a, b): (ExtractorA, ExtractorA)` to further nest extractors
-  --> tests/debug_handler/fail/too_many_extractors.rs:5:5
+  --> tests/debug_handler/fail/too_many_extractors.rs:6:5
    |
-5  | /     e1: String,
-6  | |     e2: String,
-7  | |     e3: String,
-8  | |     e4: String,
+6  | /     e1: Uri,
+7  | |     e2: Uri,
+8  | |     e3: Uri,
+9  | |     e4: Uri,
 ...  |
-20 | |     e16: String,
-21 | |     e17: String,
-   | |________________^
+21 | |     e16: Uri,
+22 | |     e17: Uri,
+   | |_____________^

axum-macros/tests/debug_handler/pass/multiple_extractors.rs

@@ -1,6 +1,7 @@
 use axum_macros::debug_handler;
+use axum::http::{Method, Uri};
 
 #[debug_handler]
-async fn handler(_one: String, _two: String, _three: String) {}
+async fn handler(_one: Method, _two: Uri, _three: String) {}
 
 fn main() {}