config: allow 'extra' in root of single-project config files

The 'extra' property was previously only declared for the projects in a
multi-project config file. Since unknown fields are considered an error
when parsing single-project config files, this made it impossible to
include arbitrary metadata via a package.json config or a
relay.config.json file. Allow 'extra' at the root of a single-project
config file to better-match the structure of projects in a multi-project
config.

fixes #5029

Author: sjbarag

compiler/crates/relay-compiler/relay-compiler-config-schema.json

@@ -1584,6 +1584,10 @@
             "type": "string"
           }
         },
+        "extra": {
+          "description": "A placeholder for allowing extra information in the config file",
+          "default": null
+        },
         "featureFlags": {
           "description": "Enable and disable experimental or legacy behaviors. WARNING! These are not stable and may change at any time.",
           "default": null,

compiler/crates/relay-compiler/src/config.rs

@@ -949,6 +949,10 @@ pub struct SingleProjectConfigFile {
     /// Opt out of source control checks/integration.
     #[serde(default)]
     pub no_source_control: Option<bool>,
+
+    /// A placeholder for allowing extra information in the config file
+    #[serde(default)]
+    extra: serde_json::Value,
 }
 
 impl Default for SingleProjectConfigFile {
@@ -972,6 +976,7 @@ impl Default for SingleProjectConfigFile {
             module_import_config: Default::default(),
             resolvers_schema_module: Default::default(),
             no_source_control: Some(false),
+            extra: Default::default(),
         }
     }
 }

compiler/crates/relay-compiler/tests/relay_compiler_integration/fixtures/extra_in_single_file_config.expected

@@ -0,0 +1,64 @@
+==================================== INPUT ====================================
+//- foo.js
+graphql`
+  fragment foo on User {
+     name
+  }`;
+
+//- relay.config.json
+{
+  "language": "typescript",
+  "schema": "./schema.graphql",
+  "extra": {
+    "is_metadata": true,
+    "tags": ["free-form", "unstructured"]
+  }
+}
+
+//- schema.graphql
+type Query { me: User }
+type User { name: String }
+==================================== OUTPUT ===================================
+//- __generated__/foo.graphql.ts
+/**
+ * <auto-generated> SignedSource<<d2b6a2fbf057fd52d8aa0869bcccbe8e>>
+ * @lightSyntaxTransform
+ * @nogrep
+ */
+
+/* tslint:disable */
+/* eslint-disable */
+// @ts-nocheck
+
+import { ReaderFragment } from 'relay-runtime';
+import { FragmentRefs } from "relay-runtime";
+export type foo$data = {
+  readonly name: string | null | undefined;
+  readonly " $fragmentType": "foo";
+};
+export type foo$key = {
+  readonly " $data"?: foo$data;
+  readonly " $fragmentSpreads": FragmentRefs<"foo">;
+};
+
+const node: ReaderFragment = {
+  "argumentDefinitions": [],
+  "kind": "Fragment",
+  "metadata": null,
+  "name": "foo",
+  "selections": [
+    {
+      "alias": null,
+      "args": null,
+      "kind": "ScalarField",
+      "name": "name",
+      "storageKey": null
+    }
+  ],
+  "type": "User",
+  "abstractKey": null
+};
+
+(node as any).hash = "01d5e51e4b7ff55557834f125c21745d";
+
+export default node;

compiler/crates/relay-compiler/tests/relay_compiler_integration/fixtures/extra_in_single_file_config.input

@@ -0,0 +1,19 @@
+//- foo.js
+graphql`
+  fragment foo on User {
+     name
+  }`;
+
+//- relay.config.json
+{
+  "language": "typescript",
+  "schema": "./schema.graphql",
+  "extra": {
+    "is_metadata": true,
+    "tags": ["free-form", "unstructured"]
+  }
+}
+
+//- schema.graphql
+type Query { me: User }
+type User { name: String }

compiler/crates/relay-compiler/tests/relay_compiler_integration_test.rs

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c8632d2cc8a8adc3915d1de9ce475bba>>
+ * @generated SignedSource<<a2971e0e5624155ca2839e4911ee608b>>
  */
 
 mod relay_compiler_integration;
@@ -96,6 +96,13 @@ async fn exec_resolvers_directive_with_root_fragment() {
     test_fixture(transform_fixture, file!(), "exec_resolvers_directive_with_root_fragment.input", "relay_compiler_integration/fixtures/exec_resolvers_directive_with_root_fragment.expected", input, expected).await;
 }
 
+#[tokio::test]
+async fn extra_in_single_file_config() {
+    let input = include_str!("relay_compiler_integration/fixtures/extra_in_single_file_config.input");
+    let expected = include_str!("relay_compiler_integration/fixtures/extra_in_single_file_config.expected");
+    test_fixture(transform_fixture, file!(), "extra_in_single_file_config.input", "relay_compiler_integration/fixtures/extra_in_single_file_config.expected", input, expected).await;
+}
+
 #[tokio::test]
 async fn fragment_alias_nested_in_inline_fragment() {
     let input = include_str!("relay_compiler_integration/fixtures/fragment_alias_nested_in_inline_fragment.input");