Support semantic non-nullable RelayResolverValue

Reviewed By: gordyf

Differential Revision: D64009842

fbshipit-source-id: 30417bd3323a30d27a9d959e59123262cebde24c

Author: captbaritone

compiler/crates/relay-schema-generation/src/lib.rs

@@ -914,7 +914,7 @@ fn return_type_to_type_annotation(
     type_definitions: &FxHashMap<ModuleResolutionKey, DocblockIr>,
     use_semantic_non_null: bool,
 ) -> DiagnosticsResult<(TypeAnnotation, Vec<i64>)> {
-    let (return_type, mut is_optional) = schema_extractor::unwrap_nullable_type(return_type);
+    let (return_type, is_optional) = schema_extractor::unwrap_nullable_type(return_type);
     let mut semantic_non_null_levels: Vec<i64> = vec![];
 
     let location = to_location(source_location, return_type);
@@ -1029,20 +1029,16 @@ fn return_type_to_type_annotation(
                                 )]);
                             }
                         }
-                        "RelayResolverValue" => {
-                            // Special case for `RelayResolverValue`, it is always optional
-                            is_optional = true;
-                            TypeAnnotation::Named(NamedTypeAnnotation {
-                                name: Identifier {
+                        "RelayResolverValue" => TypeAnnotation::Named(NamedTypeAnnotation {
+                            name: Identifier {
+                                span: location.span(),
+                                token: Token {
                                     span: location.span(),
-                                    token: Token {
-                                        span: location.span(),
-                                        kind: TokenKind::Identifier,
-                                    },
-                                    value: intern!("RelayResolverValue"),
+                                    kind: TokenKind::Identifier,
                                 },
-                            })
-                        }
+                                value: intern!("RelayResolverValue"),
+                            },
+                        }),
                         _ => {
                             return Err(vec![Diagnostic::error(
                                 SchemaGenerationError::UnSupportedGeneric {

compiler/crates/relay-schema-generation/tests/docblock/fixtures/return-relay-resolver-value.expected

@@ -76,7 +76,24 @@ Field(
             },
             root_fragment: None,
             deprecated: None,
-            semantic_non_null: None,
+            semantic_non_null: Some(
+                ConstantDirective {
+                    span: 419:431,
+                    at: Token {
+                        span: 0:0,
+                        kind: Empty,
+                    },
+                    name: Identifier {
+                        span: 419:431,
+                        token: Token {
+                            span: 0:0,
+                            kind: Empty,
+                        },
+                        value: "semanticNonNull",
+                    },
+                    arguments: None,
+                },
+            ),
             live: None,
             location: module.js:419:431,
             fragment_arguments: None,
@@ -88,7 +105,7 @@ Field(
     ),
 )
 extend type Cat {
-  complexValue: RelayResolverValue @relay_resolver(fragment_name: "Cat____relay_model_instance", generated_fragment: true, inject_fragment_data: "__relay_model_instance", type_confirmed: true, has_output_type: true, import_name: "complexValue", import_path: "module.js") @resolver_source_hash(value: "fc15c065174264428a3632fe9cf329d6")
+  complexValue: RelayResolverValue @relay_resolver(fragment_name: "Cat____relay_model_instance", generated_fragment: true, inject_fragment_data: "__relay_model_instance", type_confirmed: true, has_output_type: true, import_name: "complexValue", import_path: "module.js") @resolver_source_hash(value: "fc15c065174264428a3632fe9cf329d6") @semanticNonNull
 }
 
 

packages/relay-runtime/experimental.js

@@ -27,9 +27,20 @@ export type IdOf<A: string, Typename: void | string = void> = [
   ? {id: DataID}
   : {id: DataID, __typename: Typename};
 
-// Annotates a `RelayResolverValue` GraphQL return type
-// eslint-disable-next-line no-unused-vars
-export type RelayResolverValue<A> = A;
+/**
+ * Annotates a `RelayResolverValue` GraphQL return type. Using this type in the
+ * return position of a Relay Resolver informs Relay that it should model this
+ * field as returning a `RelayResolverValue` type. See the docs for more
+ * information:
+ *
+ * https://relay.dev/docs/next/guides/relay-resolvers/return-types/#javascript-values
+ *
+ * Note: This type forces the value to be non-maybe. This is required in order
+ * to allow the Relay compiler to to "see", via static analysis, if the field
+ * can return null or not. If the field is nullable, you can type it as
+ * returning `?RelayResolverValue<T>`.
+ */
+export type RelayResolverValue<A> = $NonMaybeType<A>;
 
 type ErrorResult<Error> = {
   ok: false,