ease upgrade path for programmatic default values (#4296)

#3814 added default value validation and coercion, deprecating `astFromValue()` (which was unsafe, used `serialize()` to uncoerce input values provided in the internal format) and replacing it with a call to `valueToLiteral()` which safely operates on external values.

This PR makes that change backwards compatible by reintroducing it as a new config option of `default` instead of replacing the existing option of `defaultValue`, where the type of `default` is:

```ts
export type GraphQLDefaultInput =
  | { value: unknown; literal?: never }
  | { literal: ConstValueNode; value?: never };
```

`default.value` is the external default value, while old config option of `defaultValue` is the internal value. Instead of removing it in v17, it is deprecated, and will be removed in v18. 

Side note: `GraphqlDefaultInput` renamed from `GraphQlDefaultValueUsage` introduced within the #3814 PR stack.

Co-authored-by: Michael Hayes <[email protected]>

integrationTests/ts/basic-test.ts

@@ -11,7 +11,7 @@ const queryType: GraphQLObjectType = new GraphQLObjectType({
       args: {
         who: {
           type: GraphQLString,
-          defaultValue: 'World',
+          default: { value: 'World' },
         },
       },
       resolve(_root, args: { who: string }) {

integrationTests/ts/esm.ts

@@ -15,7 +15,7 @@ const queryType: GraphQLObjectType = new GraphQLObjectType({
       args: {
         who: {
           type: GraphQLString,
-          defaultValue: 'World',
+          default: { value: 'World' },
         },
       },
       resolve(_root, args: { who: string }) {

src/execution/__tests__/executor-test.ts

@@ -246,7 +246,7 @@ describe('Execute: Handles basic execution tasks', () => {
             signature: {
               name: 'var',
               type: GraphQLString,
-              defaultValue: undefined,
+              default: undefined,
             },
             value: 'abc',
           },

src/execution/__tests__/variables-test.ts

@@ -142,11 +142,11 @@ const TestType = new GraphQLObjectType({
     }),
     fieldWithDefaultArgumentValue: fieldWithInputArg({
       type: GraphQLString,
-      defaultValue: 'Hello World',
+      default: { value: 'Hello World' },
     }),
     fieldWithNonNullableStringInputAndDefaultArgumentValue: fieldWithInputArg({
       type: new GraphQLNonNull(GraphQLString),
-      defaultValue: 'Hello World',
+      default: { value: 'Hello World' },
     }),
     fieldWithNestedInputObject: fieldWithInputArg({
       type: TestNestedInputObject,
@@ -187,7 +187,7 @@ const schema = new GraphQLSchema({
           type: new GraphQLNonNull(GraphQLBoolean),
           description: 'Skipped when true.',
           // default values will override operation variables in the setting of defined fragment variables that are not provided
-          defaultValue: true,
+          default: { value: true },
         },
       },
     }),

src/execution/getVariableSignature.ts

@@ -1,14 +1,13 @@
 import { GraphQLError } from '../error/GraphQLError.js';
 
-import type { VariableDefinitionNode } from '../language/ast.js';
+import type {
+  ConstValueNode,
+  VariableDefinitionNode,
+} from '../language/ast.js';
 import { print } from '../language/printer.js';
 
 import { isInputType } from '../type/definition.js';
-import type {
-  GraphQLDefaultValueUsage,
-  GraphQLInputType,
-  GraphQLSchema,
-} from '../type/index.js';
+import type { GraphQLInputType, GraphQLSchema } from '../type/index.js';
 
 import { typeFromAST } from '../utilities/typeFromAST.js';
 
@@ -21,7 +20,8 @@ import { typeFromAST } from '../utilities/typeFromAST.js';
 export interface GraphQLVariableSignature {
   name: string;
   type: GraphQLInputType;
-  defaultValue: GraphQLDefaultValueUsage | undefined;
+  defaultValue?: never;
+  default: { literal: ConstValueNode } | undefined;
 }
 
 export function getVariableSignature(
@@ -46,6 +46,6 @@ export function getVariableSignature(
   return {
     name: varName,
     type: varType,
-    defaultValue: defaultValue ? { literal: defaultValue } : undefined,
+    default: defaultValue && { literal: defaultValue },
   };
 }

src/execution/values.ts

@@ -231,11 +231,9 @@ export function experimentalGetArgumentValues(
           { nodes: node },
         );
       }
-      if (argDef.defaultValue) {
-        coercedValues[name] = coerceDefaultValue(
-          argDef.defaultValue,
-          argDef.type,
-        );
+      const coercedDefaultValue = coerceDefaultValue(argDef);
+      if (coercedDefaultValue !== undefined) {
+        coercedValues[name] = coercedDefaultValue;
       }
       continue;
     }
@@ -254,11 +252,9 @@ export function experimentalGetArgumentValues(
           !Object.hasOwn(scopedVariableValues.coerced, variableName)) &&
         !isRequiredArgument(argDef)
       ) {
-        if (argDef.defaultValue) {
-          coercedValues[name] = coerceDefaultValue(
-            argDef.defaultValue,
-            argDef.type,
-          );
+        const coercedDefaultValue = coerceDefaultValue(argDef);
+        if (coercedDefaultValue !== undefined) {
+          coercedValues[name] = coercedDefaultValue;
         }
         continue;
       }

src/index.ts

@@ -212,7 +212,7 @@ export type {
   GraphQLScalarOutputValueCoercer,
   GraphQLScalarInputValueCoercer,
   GraphQLScalarInputLiteralCoercer,
-  GraphQLDefaultValueUsage,
+  GraphQLDefaultInput,
 } from './type/index.js';
 
 // Parse and operate on GraphQL language source files.

src/type/__tests__/definition-test.ts

@@ -204,8 +204,8 @@ describe('Type System: Objects', () => {
             input: {
               description: 'Argument description.',
               type: ScalarType,
-              defaultValue: 'DefaultValue',
-              defaultValueLiteral: undefined,
+              defaultValue: undefined,
+              default: { value: 'DefaultValue' },
               deprecationReason: 'Argument deprecation reason.',
               extensions: { someExtension: 'extension' },
               astNode: dummyAny,
@@ -377,6 +377,7 @@ describe('Type System: Objects', () => {
       description: undefined,
       type: ScalarType,
       defaultValue: undefined,
+      default: undefined,
       deprecationReason: undefined,
       extensions: {},
       astNode: undefined,
@@ -493,7 +494,7 @@ describe('Type System: Interfaces', () => {
               description: 'Argument description.',
               type: ScalarType,
               defaultValue: undefined,
-              defaultValueLiteral: dummyAny,
+              default: { literal: dummyAny },
               deprecationReason: 'Argument deprecation reason.',
               extensions: { someExtension: 'extension' },
               astNode: dummyAny,
@@ -830,8 +831,8 @@ describe('Type System: Input Objects', () => {
         input: {
           description: 'Argument description.',
           type: ScalarType,
-          defaultValue: 'DefaultValue',
-          defaultValueLiteral: undefined,
+          defaultValue: undefined,
+          default: { value: 'DefaultValue' },
           deprecationReason: 'Argument deprecation reason.',
           extensions: { someExtension: 'extension' },
           astNode: dummyAny,
@@ -860,6 +861,7 @@ describe('Type System: Input Objects', () => {
         description: undefined,
         type: ScalarType,
         defaultValue: undefined,
+        default: undefined,
         deprecationReason: undefined,
         extensions: {},
         astNode: undefined,
@@ -879,6 +881,7 @@ describe('Type System: Input Objects', () => {
         description: undefined,
         type: ScalarType,
         defaultValue: undefined,
+        default: undefined,
         extensions: {},
         deprecationReason: undefined,
         astNode: undefined,
@@ -927,14 +930,15 @@ describe('Type System: Input Objects', () => {
       const inputObjType = new GraphQLInputObjectType({
         name: 'SomeInputObject',
         fields: {
-          f: { type: ScalarType, defaultValue: 3 },
+          f: { type: ScalarType, default: { value: 3 } },
         },
       });
       expect(inputObjType.getFields().f).to.deep.include({
         name: 'f',
         description: undefined,
         type: ScalarType,
-        defaultValue: { value: 3 },
+        defaultValue: undefined,
+        default: { value: 3 },
         deprecationReason: undefined,
         extensions: {},
         astNode: undefined,
@@ -947,36 +951,21 @@ describe('Type System: Input Objects', () => {
         fields: {
           f: {
             type: ScalarType,
-            defaultValueLiteral: { kind: Kind.INT, value: '3' },
+            default: { literal: { kind: Kind.INT, value: '3' } },
           },
         },
       });
       expect(inputObjType.getFields().f).to.deep.include({
         name: 'f',
         description: undefined,
         type: ScalarType,
-        defaultValue: { literal: { kind: 'IntValue', value: '3' } },
+        defaultValue: undefined,
+        default: { literal: { kind: 'IntValue', value: '3' } },
         deprecationReason: undefined,
         extensions: {},
         astNode: undefined,
       });
     });
-
-    it('rejects an Input Object type with potentially conflicting default values', () => {
-      const inputObjType = new GraphQLInputObjectType({
-        name: 'SomeInputObject',
-        fields: {
-          f: {
-            type: ScalarType,
-            defaultValue: 3,
-            defaultValueLiteral: { kind: Kind.INT, value: '3' },
-          },
-        },
-      });
-      expect(() => inputObjType.getFields()).to.throw(
-        'Argument "f" has both a defaultValue and a defaultValueLiteral property, but only one must be provided.',
-      );
-    });
   });
 });
 

src/type/__tests__/directive-test.ts

@@ -45,6 +45,7 @@ describe('Type System: Directive', () => {
       description: undefined,
       type: GraphQLString,
       defaultValue: undefined,
+      default: undefined,
       deprecationReason: undefined,
       extensions: {},
       astNode: undefined,
@@ -56,6 +57,7 @@ describe('Type System: Directive', () => {
       description: undefined,
       type: GraphQLInt,
       defaultValue: undefined,
+      default: undefined,
       deprecationReason: undefined,
       extensions: {},
       astNode: undefined,

src/type/__tests__/enumType-test.ts

@@ -71,7 +71,7 @@ const QueryType = new GraphQLObjectType({
       args: {
         fromEnum: {
           type: ComplexEnum,
-          defaultValue: 'ONE',
+          default: { value: 'ONE' },
         },
         provideGoodValue: { type: GraphQLBoolean },
         provideBadValue: { type: GraphQLBoolean },
@@ -90,6 +90,18 @@ const QueryType = new GraphQLObjectType({
         return fromEnum;
       },
     },
+    complexEnumWithLegacyDefault: {
+      type: ComplexEnum,
+      args: {
+        fromEnum: {
+          type: ComplexEnum,
+          defaultValue: Complex1,
+        },
+      },
+      resolve(_source, { fromEnum }) {
+        return fromEnum;
+      },
+    },
     thunkValuesString: {
       type: GraphQLString,
       args: {
@@ -442,6 +454,20 @@ describe('Type System: Enum Values', () => {
     });
   });
 
+  it('may be internally represented with complex values using legacy internal defaults', () => {
+    const result = executeQuery(`
+      {
+        complexEnumWithLegacyDefault
+      }
+    `);
+
+    expectJSON(result).toDeepEqual({
+      data: {
+        complexEnumWithLegacyDefault: 'ONE',
+      },
+    });
+  });
+
   it('may have values specified via a callback', () => {
     const result = executeQuery('{ thunkValuesString(fromEnum: B) }');
 

src/type/__tests__/predicate-test.ts

@@ -5,6 +5,7 @@ import { DirectiveLocation } from '../../language/directiveLocation.js';
 
 import type {
   GraphQLArgument,
+  GraphQLDefaultInput,
   GraphQLInputField,
   GraphQLInputType,
 } from '../definition.js';
@@ -634,7 +635,7 @@ describe('Type predicates', () => {
   describe('isRequiredArgument', () => {
     function buildArg(config: {
       type: GraphQLInputType;
-      defaultValue?: unknown;
+      default?: GraphQLDefaultInput;
     }): GraphQLArgument {
       const objectType = new GraphQLObjectType({
         name: 'SomeType',
@@ -660,7 +661,7 @@ describe('Type predicates', () => {
 
       const optArg2 = buildArg({
         type: GraphQLString,
-        defaultValue: null,
+        default: { value: null },
       });
       expect(isRequiredArgument(optArg2)).to.equal(false);
 
@@ -671,7 +672,7 @@ describe('Type predicates', () => {
 
       const optArg4 = buildArg({
         type: new GraphQLNonNull(GraphQLString),
-        defaultValue: 'default',
+        default: { value: 'default' },
       });
       expect(isRequiredArgument(optArg4)).to.equal(false);
     });
@@ -680,7 +681,7 @@ describe('Type predicates', () => {
   describe('isRequiredInputField', () => {
     function buildInputField(config: {
       type: GraphQLInputType;
-      defaultValue?: unknown;
+      default?: GraphQLDefaultInput;
     }): GraphQLInputField {
       const inputObjectType = new GraphQLInputObjectType({
         name: 'SomeType',
@@ -706,7 +707,7 @@ describe('Type predicates', () => {
 
       const optField2 = buildInputField({
         type: GraphQLString,
-        defaultValue: null,
+        default: { value: null },
       });
       expect(isRequiredInputField(optField2)).to.equal(false);
 
@@ -717,7 +718,7 @@ describe('Type predicates', () => {
 
       const optField4 = buildInputField({
         type: new GraphQLNonNull(GraphQLString),
-        defaultValue: 'default',
+        default: { value: 'default' },
       });
       expect(isRequiredInputField(optField4)).to.equal(false);
     });