Allow post-validation FromInputValue errors

docs/book/content/types/scalars.md

@@ -113,7 +113,7 @@ The example below is used just for illustration.
 #        }
 #    }
 # }
-
+#
 use juniper::{Value, ParseScalarResult, ParseScalarValue};
 use date::Date;
 
@@ -128,17 +128,18 @@ where
     }
 
     // Define how to parse a primitive type into your custom scalar.
-    fn from_input_value(v: &InputValue) -> Option<Date> {
-        v.as_scalar_value()
-        .and_then(|v| v.as_str())
-        .and_then(|s| s.parse().ok())
+    // NOTE: The error type should implement `IntoFieldError<S>`.
+    fn from_input_value(v: &InputValue) -> Result<Date, String> {
+        v.as_string_value()
+            .ok_or_else(|| format!("Expected `String`, found: {}", v))
+            .and_then(|s| s.parse().map_err(|e| format!("Failed to parse `Date`: {}", e)))
     }
 
     // Define how to parse a string value.
     fn from_str<'a>(value: ScalarToken<'a>) -> ParseScalarResult<'a, S> {
         <String as ParseScalarValue<S>>::from_str(value)
     }
 }
-
+#
 # fn main() {}
 ```

integration_tests/async_await/src/main.rs

@@ -70,11 +70,18 @@ impl Query {
     }
 }
 
-#[tokio::test]
-async fn async_simple() {
-    let schema = RootNode::new(Query, EmptyMutation::new(), EmptySubscription::new());
-    let doc = r#"
-        query {
+fn main() {}
+
+#[cfg(test)]
+mod tests {
+    use juniper::{graphql_value, EmptyMutation, EmptySubscription, GraphQLError, RootNode, Value};
+
+    use super::Query;
+
+    #[tokio::test]
+    async fn async_simple() {
+        let schema = RootNode::new(Query, EmptyMutation::new(), EmptySubscription::new());
+        let doc = r#"query {
             fieldSync
             fieldAsyncPlain
             delayed
@@ -83,39 +90,37 @@ async fn async_simple() {
                 name
                 delayed
             }
-        }
-    "#;
+        }"#;
 
-    let vars = Default::default();
-    let (res, errs) = juniper::execute(doc, None, &schema, &vars, &())
-        .await
-        .unwrap();
+        let vars = Default::default();
+        let (res, errs) = juniper::execute(doc, None, &schema, &vars, &())
+            .await
+            .unwrap();
 
-    assert!(errs.is_empty());
+        assert!(errs.is_empty());
 
-    let obj = res.into_object().unwrap();
-    let value = Value::Object(obj);
+        let obj = res.into_object().unwrap();
+        let value = Value::Object(obj);
 
-    assert_eq!(
-        value,
-        graphql_value!({
-            "delayed": true,
-            "fieldAsyncPlain": "field_async_plain",
-            "fieldSync": "field_sync",
-            "user": {
+        assert_eq!(
+            value,
+            graphql_value!({
                 "delayed": true,
-                "kind": "USER",
-                "name": "user1",
-            },
-        }),
-    );
-}
+                "fieldAsyncPlain": "field_async_plain",
+                "fieldSync": "field_sync",
+                "user": {
+                    "delayed": true,
+                    "kind": "USER",
+                    "name": "user1",
+                },
+            }),
+        );
+    }
 
-#[tokio::test]
-async fn async_field_validation_error() {
-    let schema = RootNode::new(Query, EmptyMutation::new(), EmptySubscription::new());
-    let doc = r#"
-        query {
+    #[tokio::test]
+    async fn async_field_validation_error() {
+        let schema = RootNode::new(Query, EmptyMutation::new(), EmptySubscription::new());
+        let doc = r#"query {
             nonExistentField
             fieldSync
             fieldAsyncPlain
@@ -125,40 +130,38 @@ async fn async_field_validation_error() {
                 name
                 delayed
             }
-        }
-    "#;
-
-    let vars = Default::default();
-    let result = juniper::execute(doc, None, &schema, &vars, &()).await;
-    assert!(result.is_err());
-
-    let error = result.err().unwrap();
-    let is_validation_error = match error {
-        GraphQLError::ValidationError(_) => true,
-        _ => false,
-    };
-    assert!(is_validation_error);
-}
-
-// FIXME: test seems broken by design, re-enable later
-// #[tokio::test]
-// async fn resolve_into_stream_validation_error() {
-//     let schema = RootNode::new(Query, EmptyMutation::new(), EmptySubscription::new());
-//     let doc = r#"
-//         subscription {
-//             nonExistent
-//         }
-//     "#;
-//     let vars = Default::default();
-//     let result = juniper::resolve_into_stream(doc, None, &schema, &vars, &()).await;
-//     assert!(result.is_err());
-
-//     let error = result.err().unwrap();
-//     let is_validation_error = match error {
-//         GraphQLError::ValidationError(_) => true,
-//         _ => false,
-//     };
-//     assert!(is_validation_error);
-// }
+        }"#;
+
+        let vars = Default::default();
+        let result = juniper::execute(doc, None, &schema, &vars, &()).await;
+        assert!(result.is_err());
+
+        let error = result.err().unwrap();
+        let is_validation_error = match error {
+            GraphQLError::ValidationError(_) => true,
+            _ => false,
+        };
+        assert!(is_validation_error);
+    }
 
-fn main() {}
+    // FIXME: test seems broken by design, re-enable later
+    // #[tokio::test]
+    // async fn resolve_into_stream_validation_error() {
+    //     let schema = RootNode::new(Query, EmptyMutation::new(), EmptySubscription::new());
+    //     let doc = r#"
+    //         subscription {
+    //             nonExistent
+    //         }
+    //     "#;
+    //     let vars = Default::default();
+    //     let result = juniper::resolve_into_stream(doc, None, &schema, &vars, &()).await;
+    //     assert!(result.is_err());
+
+    //     let error = result.err().unwrap();
+    //     let is_validation_error = match error {
+    //         GraphQLError::ValidationError(_) => true,
+    //         _ => false,
+    //     };
+    //     assert!(is_validation_error);
+    // }
+}

integration_tests/codegen_fail/fail/enum/derive_no_fields.stderr

@@ -1,7 +1,8 @@
 error: GraphQL enum expects at least one field
- --> $DIR/derive_no_fields.rs:2:1
+
+  = note: https://spec.graphql.org/June2018/#sec-Enums
+
+ --> fail/enum/derive_no_fields.rs:2:1
   |
 2 | pub enum Test {}
-  | ^^^^^^^^^^^^^^^^
-  |
-  = note: https://spec.graphql.org/June2018/#sec-Enums
+  | ^^^

integration_tests/codegen_fail/fail/input-object/derive_incompatible_object.stderr

@@ -1,31 +1,39 @@
 error[E0277]: the trait bound `ObjectA: IsInputType<__S>` is not satisfied
- --> $DIR/derive_incompatible_object.rs:6:10
-  |
-6 | #[derive(juniper::GraphQLInputObject)]
-  |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `IsInputType<__S>` is not implemented for `ObjectA`
-  |
-  = note: required by `juniper::marker::IsInputType::mark`
-  = note: this error originates in the derive macro `juniper::GraphQLInputObject` (in Nightly builds, run with -Z macro-backtrace for more info)
+   --> fail/input-object/derive_incompatible_object.rs:6:10
+    |
+6   | #[derive(juniper::GraphQLInputObject)]
+    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `IsInputType<__S>` is not implemented for `ObjectA`
+    |
+note: required by `juniper::marker::IsInputType::mark`
+   --> $WORKSPACE/juniper/src/types/marker.rs
+    |
+    |     fn mark() {}
+    |     ^^^^^^^^^
+    = note: this error originates in the derive macro `juniper::GraphQLInputObject` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `ObjectA: FromInputValue<__S>` is not satisfied
- --> $DIR/derive_incompatible_object.rs:6:10
+ --> fail/input-object/derive_incompatible_object.rs:6:10
   |
 6 | #[derive(juniper::GraphQLInputObject)]
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromInputValue<__S>` is not implemented for `ObjectA`
   |
   = note: this error originates in the derive macro `juniper::GraphQLInputObject` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `ObjectA: FromInputValue<__S>` is not satisfied
- --> $DIR/derive_incompatible_object.rs:6:10
-  |
-6 | #[derive(juniper::GraphQLInputObject)]
-  |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromInputValue<__S>` is not implemented for `ObjectA`
-  |
-  = note: required by `from_input_value`
-  = note: this error originates in the derive macro `juniper::GraphQLInputObject` (in Nightly builds, run with -Z macro-backtrace for more info)
+   --> fail/input-object/derive_incompatible_object.rs:6:10
+    |
+6   | #[derive(juniper::GraphQLInputObject)]
+    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromInputValue<__S>` is not implemented for `ObjectA`
+    |
+note: required by `from_input_value`
+   --> $WORKSPACE/juniper/src/ast.rs
+    |
+    |     fn from_input_value(v: &InputValue<S>) -> Result<Self, Self::Error>;
+    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+    = note: this error originates in the derive macro `juniper::GraphQLInputObject` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0599]: no method named `to_input_value` found for struct `ObjectA` in the current scope
- --> $DIR/derive_incompatible_object.rs:6:10
+ --> fail/input-object/derive_incompatible_object.rs:6:10
   |
 2 | struct ObjectA {
   | -------------- method `to_input_value` not found for this

integration_tests/codegen_fail/fail/input-object/derive_no_fields.stderr

@@ -1,7 +1,8 @@
 error: GraphQL input object expects at least one field
- --> $DIR/derive_no_fields.rs:2:1
+
+  = note: https://spec.graphql.org/June2018/#sec-Input-Objects
+
+ --> fail/input-object/derive_no_fields.rs:2:1
   |
 2 | struct Object {}
-  | ^^^^^^^^^^^^^^^^
-  |
-  = note: https://spec.graphql.org/June2018/#sec-Input-Objects
+  | ^^^^^^

integration_tests/codegen_fail/fail/input-object/derive_no_underscore.stderr

@@ -1,7 +1,8 @@
 error: All types and directives defined within a schema must not have a name which begins with `__` (two underscores), as this is used exclusively by GraphQL’s introspection system.
- --> $DIR/derive_no_underscore.rs:3:15
+
+  = note: https://spec.graphql.org/June2018/#sec-Schema
+
+ --> fail/input-object/derive_no_underscore.rs:3:15
   |
 3 |     #[graphql(name = "__test")]
   |               ^^^^
-  |
-  = note: https://spec.graphql.org/June2018/#sec-Schema

integration_tests/codegen_fail/fail/input-object/derive_unique_name.stderr

@@ -1,9 +1,9 @@
 error: GraphQL input object does not allow fields with the same name
- --> $DIR/derive_unique_name.rs:4:5
-  |
-4 | /     #[graphql(name = "test")]
-5 | |     test2: String,
-  | |_________________^
-  |
+
   = help: There is at least one other field with the same name `test`, possibly renamed via the #[graphql] attribute
   = note: https://spec.graphql.org/June2018/#sec-Input-Objects
+
+ --> fail/input-object/derive_unique_name.rs:4:5
+  |
+4 |     #[graphql(name = "test")]
+  |     ^

integration_tests/codegen_fail/fail/interface/argument_double_underscored.stderr

@@ -1,10 +1,11 @@
 error: All types and directives defined within a schema must not have a name which begins with `__` (two underscores), as this is used exclusively by GraphQL’s introspection system.
+
+  = note: https://spec.graphql.org/June2018/#sec-Schema
+
   --> $DIR/argument_double_underscored.rs:14:18
    |
 14 |     fn id(&self, __num: i32) -> &str {
    |                  ^^^^^
-   |
-   = note: https://spec.graphql.org/June2018/#sec-Schema
 
 error[E0412]: cannot find type `CharacterValue` in this scope
  --> $DIR/argument_double_underscored.rs:4:18

integration_tests/codegen_fail/fail/interface/argument_non_input_type.stderr

@@ -1,14 +1,18 @@
 error[E0277]: the trait bound `ObjA: IsInputType<__S>` is not satisfied
-  --> $DIR/argument_non_input_type.rs:16:1
-   |
-16 | #[graphql_interface(for = ObjA)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `IsInputType<__S>` is not implemented for `ObjA`
-   |
-   = note: required by `juniper::marker::IsInputType::mark`
-   = note: this error originates in the attribute macro `graphql_interface` (in Nightly builds, run with -Z macro-backtrace for more info)
+   --> fail/interface/argument_non_input_type.rs:16:1
+    |
+16  | #[graphql_interface(for = ObjA)]
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `IsInputType<__S>` is not implemented for `ObjA`
+    |
+note: required by `juniper::marker::IsInputType::mark`
+   --> $WORKSPACE/juniper/src/types/marker.rs
+    |
+    |     fn mark() {}
+    |     ^^^^^^^^^
+    = note: this error originates in the attribute macro `graphql_interface` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `ObjA: FromInputValue<__S>` is not satisfied
-  --> $DIR/argument_non_input_type.rs:16:1
+  --> fail/interface/argument_non_input_type.rs:16:1
    |
 16 | #[graphql_interface(for = ObjA)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromInputValue<__S>` is not implemented for `ObjA`

integration_tests/codegen_fail/fail/interface/downcast_method_conflicts_with_external_downcast_fn.stderr

@@ -1,11 +1,12 @@
 error: GraphQL interface trait method `as_obja` conflicts with the external downcast function `downcast_obja` declared on the trait to downcast into the implementer type `ObjA`
+
+  = note: https://spec.graphql.org/June2018/#sec-Interfaces
+  = note: use `#[graphql(ignore)]` attribute argument to ignore this trait method for interface implementers downcasting
+
   --> $DIR/downcast_method_conflicts_with_external_downcast_fn.rs:26:5
    |
 26 |     fn as_obja(&self) -> Option<&ObjA>;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: https://spec.graphql.org/June2018/#sec-Interfaces
-   = note: use `#[graphql(ignore)]` attribute argument to ignore this trait method for interface implementers downcasting
+   |     ^^
 
 error[E0412]: cannot find type `CharacterValue` in this scope
  --> $DIR/downcast_method_conflicts_with_external_downcast_fn.rs:4:18

integration_tests/codegen_fail/fail/interface/downcast_method_wrong_input_args.stderr

@@ -1,10 +1,11 @@
 error: GraphQL interface expects trait method to accept `&self` only and, optionally, `&Context`
+
+  = note: https://spec.graphql.org/June2018/#sec-Interfaces
+
   --> $DIR/downcast_method_wrong_input_args.rs:10:10
    |
 10 |     fn a(&self, ctx: &(), rand: u8) -> Option<&Human> {
-   |          ^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: https://spec.graphql.org/June2018/#sec-Interfaces
+   |          ^
 
 error[E0412]: cannot find type `CharacterValue` in this scope
   --> $DIR/downcast_method_wrong_input_args.rs:16:18