fix: do not create lookups for non resolvable keys

protographic/src/sdl-to-proto-visitor.ts

@@ -96,6 +96,14 @@ interface ProtoType {
   isRepeated: boolean;
 }
 
+/**
+ * Data structure for key directive
+ */
+interface KeyDirective {
+  keyString: string;
+  resolvable: boolean;
+}
+
 /**
  * Visitor that converts GraphQL SDL to Protocol Buffer text definition
  *
@@ -592,8 +600,11 @@ export class GraphQLToProtoTextVisitor {
 
           const normalizedKeysSet = new Set<string>();
           for (const keyDirective of keyDirectives) {
-            const keyString = this.getKeyFromDirective(keyDirective);
-            if (!keyString) continue;
+            const keyInfo = this.getKeyInfoFromDirective(keyDirective);
+            if (!keyInfo) continue;
+
+            const { keyString, resolvable } = keyInfo;
+            if (!resolvable) continue;
 
             const normalizedKey = keyString
               .split(/[,\s]+/)
@@ -1039,21 +1050,37 @@ Example:
   }
 
   /**
-   * Extract key fields from a directive
+   * Extract key info from a directive
    *
    * The @key directive specifies which fields form the entity's primary key.
    * We extract these for creating appropriate lookup methods.
    *
    * @param directive - The @key directive from the GraphQL AST
-   * @returns Array of field names that form the key
+   * @returns An object with the key fields and whether it is resolvable
    */
-  private getKeyFromDirective(directive: DirectiveNode): string | null {
-    const fieldsArg = directive.arguments?.find((arg: ArgumentNode) => arg.name.value === 'fields');
-    if (fieldsArg && fieldsArg.value.kind === 'StringValue') {
-      const stringValue = fieldsArg.value as StringValueNode;
-      return stringValue.value;
+  private getKeyInfoFromDirective(directive: DirectiveNode): KeyDirective | null {
+    const fieldsArgs = directive.arguments?.find((arg: ArgumentNode) => arg.name.value === 'fields');
+    const resolvableArg = directive.arguments?.find((arg: ArgumentNode) => arg.name.value === 'resolvable');
+
+    if (!fieldsArgs && !resolvableArg) {
+      return null;
+    }
+
+    const result: KeyDirective = {
+      keyString: '',
+      resolvable: true,
+    };
+
+    if (fieldsArgs && fieldsArgs.value.kind === 'StringValue') {
+      const stringValue = fieldsArgs.value as StringValueNode;
+      result.keyString = stringValue.value;
     }
-    return null;
+
+    if (resolvableArg && resolvableArg.value.kind === 'BooleanValue') {
+      result.resolvable = resolvableArg.value.value;
+    }
+
+    return result;
   }
 
   /**

protographic/tests/sdl-to-proto/04-federation.test.ts

@@ -842,6 +842,232 @@ describe('SDL to Proto - Federation and Special Types', () => {
         repeated Product products = 1;
       }
 
+      message Product {
+        string id = 1;
+        string manufacturer_id = 2;
+        string product_code = 3;
+        string name = 4;
+        double price = 5;
+      }"
+    `);
+  });
+  test('should not generate lookup methods for non-resolvable keys', () => {
+    const sdl = `
+      scalar openfed__FieldSet
+      directive @key(fields: openfed__FieldSet!, resolvable: Boolean = true) repeatable on INTERFACE | OBJECT
+
+      type Product @key(fields: "id", resolvable: false) @key(fields: "manufacturerId productCode", resolvable: false) {
+        id: ID!
+        manufacturerId: ID!
+        productCode: String!
+        name: String!
+        price: Float!
+      }
+
+      type Query {
+        products: [Product!]!
+      }
+    `;
+
+    const { proto: protoText } = compileGraphQLToProto(sdl);
+
+    // Validate Proto definition
+    expectValidProto(protoText);
+
+    // Check that no lookup methods are generated for non-resolvable keys
+    expect(protoText).toMatchInlineSnapshot(`
+      "syntax = "proto3";
+      package service.v1;
+
+      // Service definition for DefaultService
+      service DefaultService {
+        rpc QueryProducts(QueryProductsRequest) returns (QueryProductsResponse) {}
+      }
+
+      // Request message for products operation.
+      message QueryProductsRequest {
+      }
+      // Response message for products operation.
+      message QueryProductsResponse {
+        repeated Product products = 1;
+      }
+
+      message Product {
+        string id = 1;
+        string manufacturer_id = 2;
+        string product_code = 3;
+        string name = 4;
+        double price = 5;
+      }"
+    `);
+  });
+  test('should generate lookup methods for resolvable keys', () => {
+    const sdl = `
+      scalar openfed__FieldSet
+      directive @key(fields: openfed__FieldSet!, resolvable: Boolean = true) repeatable on INTERFACE | OBJECT
+
+      type Product @key(fields: "id", resolvable: false) @key(fields: "manufacturerId productCode", resolvable: true) {
+        id: ID!
+        manufacturerId: ID!
+        productCode: String!
+        name: String!
+        price: Float!
+      }
+
+      type Query {
+        products: [Product!]!
+      }
+    `;
+
+    const { proto: protoText } = compileGraphQLToProto(sdl);
+
+    // Validate Proto definition
+    expectValidProto(protoText);
+
+    // Expect that only the resolvable key is generated
+    expect(protoText).toMatchInlineSnapshot(`
+      "syntax = "proto3";
+      package service.v1;
+
+      // Service definition for DefaultService
+      service DefaultService {
+        // Lookup Product entity by manufacturerId and productCode
+        rpc LookupProductByManufacturerIdAndProductCode(LookupProductByManufacturerIdAndProductCodeRequest) returns (LookupProductByManufacturerIdAndProductCodeResponse) {}
+        rpc QueryProducts(QueryProductsRequest) returns (QueryProductsResponse) {}
+      }
+
+      // Key message for Product entity lookup
+      message LookupProductByManufacturerIdAndProductCodeRequestKey {
+        // Key field for Product entity lookup.
+        string manufacturer_id = 1;
+        // Key field for Product entity lookup.
+        string product_code = 2;
+      }
+
+      // Request message for Product entity lookup.
+      message LookupProductByManufacturerIdAndProductCodeRequest {
+        /*
+         * List of keys to look up Product entities.
+         * Order matters - each key maps to one entity in LookupProductByManufacturerIdAndProductCodeResponse.
+         */
+        repeated LookupProductByManufacturerIdAndProductCodeRequestKey keys = 1;
+      }
+
+      // Response message for Product entity lookup.
+      message LookupProductByManufacturerIdAndProductCodeResponse {
+        /*
+         * List of Product entities in the same order as the keys in LookupProductByManufacturerIdAndProductCodeRequest.
+         * Always return the same number of entities as keys. Use null for entities that cannot be found.
+         * 
+         * Example:
+         *   LookupUserByIdRequest:
+         *     keys:
+         *       - id: 1
+         *       - id: 2
+         *   LookupUserByIdResponse:
+         *     result:
+         *       - id: 1 # User with id 1 found
+         *       - null  # User with id 2 not found
+         */
+        repeated Product result = 1;
+      }
+
+      // Request message for products operation.
+      message QueryProductsRequest {
+      }
+      // Response message for products operation.
+      message QueryProductsResponse {
+        repeated Product products = 1;
+      }
+
+      message Product {
+        string id = 1;
+        string manufacturer_id = 2;
+        string product_code = 3;
+        string name = 4;
+        double price = 5;
+      }"
+    `);
+  });
+  test('should generate lookup method when resolvable is not specified', () => {
+    const sdl = `
+      scalar openfed__FieldSet
+      directive @key(fields: openfed__FieldSet!, resolvable: Boolean = true) repeatable on INTERFACE | OBJECT
+
+      type Product @key(fields: "id", resolvable: false) @key(fields: "manufacturerId productCode") {
+        id: ID!
+        manufacturerId: ID!
+        productCode: String!
+        name: String!
+        price: Float!
+      }
+
+      type Query {
+        products: [Product!]!
+      }
+    `;
+
+    const { proto: protoText } = compileGraphQLToProto(sdl);
+
+    // Validate Proto definition
+    expectValidProto(protoText);
+
+    // Expect that only the resolvable key is generated
+    expect(protoText).toMatchInlineSnapshot(`
+      "syntax = "proto3";
+      package service.v1;
+
+      // Service definition for DefaultService
+      service DefaultService {
+        // Lookup Product entity by manufacturerId and productCode
+        rpc LookupProductByManufacturerIdAndProductCode(LookupProductByManufacturerIdAndProductCodeRequest) returns (LookupProductByManufacturerIdAndProductCodeResponse) {}
+        rpc QueryProducts(QueryProductsRequest) returns (QueryProductsResponse) {}
+      }
+
+      // Key message for Product entity lookup
+      message LookupProductByManufacturerIdAndProductCodeRequestKey {
+        // Key field for Product entity lookup.
+        string manufacturer_id = 1;
+        // Key field for Product entity lookup.
+        string product_code = 2;
+      }
+
+      // Request message for Product entity lookup.
+      message LookupProductByManufacturerIdAndProductCodeRequest {
+        /*
+         * List of keys to look up Product entities.
+         * Order matters - each key maps to one entity in LookupProductByManufacturerIdAndProductCodeResponse.
+         */
+        repeated LookupProductByManufacturerIdAndProductCodeRequestKey keys = 1;
+      }
+
+      // Response message for Product entity lookup.
+      message LookupProductByManufacturerIdAndProductCodeResponse {
+        /*
+         * List of Product entities in the same order as the keys in LookupProductByManufacturerIdAndProductCodeRequest.
+         * Always return the same number of entities as keys. Use null for entities that cannot be found.
+         * 
+         * Example:
+         *   LookupUserByIdRequest:
+         *     keys:
+         *       - id: 1
+         *       - id: 2
+         *   LookupUserByIdResponse:
+         *     result:
+         *       - id: 1 # User with id 1 found
+         *       - null  # User with id 2 not found
+         */
+        repeated Product result = 1;
+      }
+
+      // Request message for products operation.
+      message QueryProductsRequest {
+      }
+      // Response message for products operation.
+      message QueryProductsResponse {
+        repeated Product products = 1;
+      }
+
       message Product {
         string id = 1;
         string manufacturer_id = 2;