fix: add validation for batchKey requiring either body or query parameters

src/core/blueprint/error.rs

@@ -55,6 +55,9 @@ pub enum BlueprintError {
     #[error("Batching capability was used without enabling it in upstream")]
     IncorrectBatchingUsage,
 
+    #[error("batchKey requires either body or query parameters")]
+    BatchKeyRequiresEitherBodyOrQuery,
+
     #[error("script is required")]
     ScriptIsRequired,
 

src/core/blueprint/operators/http.rs

@@ -34,6 +34,12 @@ pub fn compile_http(
             .unit()
             .trace("query"),
         )
+        .and(
+            Valid::<(), BlueprintError>::fail(BlueprintError::BatchKeyRequiresEitherBodyOrQuery)
+                .when(|| {
+                    !http.batch_key.is_empty() && (http.body.is_none() && http.query.is_empty())
+                }),
+        )
         .and(Valid::succeed(http.url.as_str()))
         .zip(mustache_headers)
         .and_then(|(base_url, headers)| {

tests/core/snapshots/batching-validation.md_error.snap

@@ -3,6 +3,15 @@ source: tests/core/spec.rs
 expression: errors
 ---
 [
+  {
+    "message": "batchKey requires either body or query parameters",
+    "trace": [
+      "Query",
+      "posts",
+      "@http"
+    ],
+    "description": null
+  },
   {
     "message": "Request body batching requires exactly one dynamic value in the body.",
     "trace": [

tests/core/snapshots/test-batch-operator-post.md_error.snap

@@ -4,12 +4,11 @@ expression: errors
 ---
 [
   {
-    "message": "Request body batching requires exactly one dynamic value in the body.",
+    "message": "batchKey requires either body or query parameters",
     "trace": [
       "Query",
       "user",
-      "@http",
-      "body"
+      "@http"
     ],
     "description": null
   }

tests/execution/batching-validation.md

@@ -14,6 +14,12 @@ type User {
   name: String
 }
 
+type Post {
+  id: Int
+  title: String
+  body: String
+}
+
 type Query {
   user(id: Int!): User
     @http(
@@ -22,6 +28,7 @@ type Query {
       body: {uId: "{{.args.id}}", userId: "{{.args.id}}"}
       batchKey: ["id"]
     )
+  posts: [Post] @http(url: "http://jsonplaceholder.typicode.com/posts", batchKey: ["id"])
   userWithId(id: Int!): User
     @http(
       url: "http://jsonplaceholder.typicode.com/users"