fix(https): align canonical binding semantics

crates/wip-https/tests/codecs.rs

@@ -9,11 +9,12 @@ use wip_https::wip_protocol::{
     TypeDeclaration, TypeExpr, UnionCase, Value,
 };
 use wip_https::{
-    ClientResponseError, DecodedResponse, Endpoint, InvalidResponseKind, Limits,
-    decode_call_operation_metadata, decode_call_operation_request, decode_call_operation_response,
-    decode_fetch_interface_request, decode_fetch_interface_response, decode_fetch_request,
-    decode_fetch_response, decode_fetch_tree_request, decode_fetch_tree_response,
-    encode_call_operation_request, encode_call_operation_response, encode_fetch_interface_request,
+    ClientResponseError, CodecError, DecodedResponse, Endpoint, InvalidResponseKind, Limits,
+    ResourceLimitKind, decode_call_operation_metadata, decode_call_operation_request,
+    decode_call_operation_response, decode_fetch_interface_request,
+    decode_fetch_interface_response, decode_fetch_request, decode_fetch_response,
+    decode_fetch_tree_request, decode_fetch_tree_response, encode_call_operation_request,
+    encode_call_operation_response, encode_fetch_interface_request,
     encode_fetch_interface_response, encode_fetch_request, encode_fetch_response,
     encode_fetch_tree_request, encode_fetch_tree_response,
 };
@@ -193,6 +194,36 @@ fn call_request() -> CallOperationRequest {
     }
 }
 
+#[test]
+fn every_single_interaction_request_accepts_json() {
+    let fetch =
+        encode_fetch_request(&endpoint(), &FetchRequest { path: "/".into() }, limits()).unwrap();
+    let fetch_tree = encode_fetch_tree_request(
+        &endpoint(),
+        &FetchTreeRequest {
+            path: "/".into(),
+            depth: 1,
+            limit: 1,
+        },
+        limits(),
+    )
+    .unwrap();
+    let fetch_interface = encode_fetch_interface_request(
+        &endpoint(),
+        &FetchInterfaceRequest {
+            interface: "interface-v1".into(),
+        },
+        limits(),
+    )
+    .unwrap();
+    let call = encode_call_operation_request(&endpoint(), &call_request(), &descriptor(), limits())
+        .unwrap();
+
+    for request in [fetch, fetch_tree, fetch_interface, call] {
+        assert_eq!(request.headers()["accept"], "application/json");
+    }
+}
+
 #[test]
 fn fetch_round_trips_direct_body_and_body_validator() {
     let request = FetchRequest {
@@ -362,11 +393,21 @@ fn malformed_unknown_null_and_noncanonical_base64_are_rejected() {
 #[test]
 fn caller_limits_bound_bytes_and_nesting() {
     let tiny = Limits::new(8, 8, 2, 1).unwrap();
-    assert!(decode_fetch_request(br#"{"path":"/long"}"#, tiny).is_err());
+    let too_large = decode_fetch_request(br#"{"path":"/long"}"#, tiny).unwrap_err();
+    assert!(matches!(&too_large, CodecError::BodyTooLarge { .. }));
+    assert_eq!(
+        too_large.resource_limit_kind(),
+        Some(ResourceLimitKind::RepresentationBytes)
+    );
 
     let nested = br#"{"path":[[["/"]]]}"#;
     let nesting_limited = Limits::new(1024, 1024, 2, 1).unwrap();
-    assert!(decode_fetch_request(nested, nesting_limited).is_err());
+    let too_deep = decode_fetch_request(nested, nesting_limited).unwrap_err();
+    assert!(matches!(&too_deep, CodecError::NestingTooDeep { .. }));
+    assert_eq!(
+        too_deep.resource_limit_kind(),
+        Some(ResourceLimitKind::Logical)
+    );
 
     let outbound_limited = Limits::new(1_000_000, 1_000_000, 1, 10).unwrap();
     assert!(