Deprecated directive

This adds a new directive as part of the experimental schema language:

```
directive @deprecated(reason: String = "No longer supported") on FIELD_DEFINITION | ENUM_VALUE
```

It also adds support for this directive in the schemaPrinter and buildASTSchema.

Additionally exports a new helper `specifiedDirectives` which is encoured to be used when addressing the collection of all directives defined by the spec. The `@deprecated` directive is optimistically added to this collection. While it's currently experimental, it will become part of the schema definition language RFC.

src/execution/values.js

@@ -54,7 +54,7 @@ export function getVariableValues(
 export function getArgumentValues(
   argDefs: ?Array<GraphQLArgument>,
   argASTs: ?Array<Argument>,
-  variableValues: { [key: string]: mixed }
+  variableValues?: ?{ [key: string]: mixed }
 ): { [key: string]: mixed } {
   if (!argDefs || !argASTs) {
     return {};

src/index.js

@@ -66,9 +66,14 @@ export {
   GraphQLBoolean,
   GraphQLID,
 
-  // Built-in Directives
+  // Specified Directives
+  specifiedDirectives,
   GraphQLIncludeDirective,
   GraphQLSkipDirective,
+  GraphQLDeprecatedDirective,
+
+  // Constant Deprecation Reason
+  DEFAULT_DEPRECATION_REASON,
 
   // Meta-field definitions.
   SchemaMetaFieldDef,

src/type/directives.js

@@ -13,7 +13,7 @@ import type {
   GraphQLFieldConfigArgumentMap,
   GraphQLArgument
 } from './definition';
-import { GraphQLBoolean } from './scalars';
+import { GraphQLString, GraphQLBoolean } from './scalars';
 import invariant from '../jsutils/invariant';
 import { assertValidName } from '../utilities/assertValidName';
 
@@ -99,7 +99,7 @@ type GraphQLDirectiveConfig = {
 }
 
 /**
- * Used to conditionally include fields or fragments
+ * Used to conditionally include fields or fragments.
  */
 export const GraphQLIncludeDirective = new GraphQLDirective({
   name: 'include',
@@ -120,7 +120,7 @@ export const GraphQLIncludeDirective = new GraphQLDirective({
 });
 
 /**
- * Used to conditionally skip (exclude) fields or fragments
+ * Used to conditionally skip (exclude) fields or fragments.
  */
 export const GraphQLSkipDirective = new GraphQLDirective({
   name: 'skip',
@@ -139,3 +139,40 @@ export const GraphQLSkipDirective = new GraphQLDirective({
     }
   },
 });
+
+/**
+ * Constant string used for default reason for a deprecation.
+ */
+export const DEFAULT_DEPRECATION_REASON = 'No longer supported';
+
+/**
+ * Used to declare element of a GraphQL schema as deprecated.
+ */
+export const GraphQLDeprecatedDirective = new GraphQLDirective({
+  name: 'deprecated',
+  description:
+    'Marks an element of a GraphQL schema as no longer supported.',
+  locations: [
+    DirectiveLocation.FIELD_DEFINITION,
+    DirectiveLocation.ENUM_VALUE,
+  ],
+  args: {
+    reason: {
+      type: GraphQLString,
+      description:
+        'Explains why this element was deprecated, usually also including a ' +
+        'suggestion for how to access supported similar data. Formatted' +
+        'in [Markdown](https://daringfireball.net/projects/markdown/).',
+      defaultValue: DEFAULT_DEPRECATION_REASON
+    }
+  },
+});
+
+/**
+ * The full list of specified directives.
+ */
+export const specifiedDirectives: Array<GraphQLDirective> = [
+  GraphQLIncludeDirective,
+  GraphQLSkipDirective,
+  GraphQLDeprecatedDirective,
+];

src/type/index.js

@@ -42,9 +42,14 @@ export {
   // Directives Definition
   GraphQLDirective,
 
-  // Built-in Directives
+  // Specified Directives
+  specifiedDirectives,
   GraphQLIncludeDirective,
   GraphQLSkipDirective,
+  GraphQLDeprecatedDirective,
+
+  // Constant Deprecation Reason
+  DEFAULT_DEPRECATION_REASON,
 } from './directives';
 
 // Common built-in scalar instances.

src/type/schema.js

@@ -17,11 +17,7 @@ import {
   GraphQLNonNull
 } from './definition';
 import type { GraphQLType, GraphQLAbstractType } from './definition';
-import {
-  GraphQLDirective,
-  GraphQLIncludeDirective,
-  GraphQLSkipDirective
-} from './directives';
+import { GraphQLDirective, specifiedDirectives } from './directives';
 import { __Schema } from './introspection';
 import find from '../jsutils/find';
 import invariant from '../jsutils/invariant';
@@ -38,21 +34,20 @@ import { isEqualType, isTypeSubTypeOf } from '../utilities/typeComparators';
  * Example:
  *
  *     const MyAppSchema = new GraphQLSchema({
- *       query: MyAppQueryRootType
- *       mutation: MyAppMutationRootType
- *     });
+ *       query: MyAppQueryRootType,
+ *       mutation: MyAppMutationRootType,
+ *     })
  *
  * Note: If an array of `directives` are provided to GraphQLSchema, that will be
  * the exact list of directives represented and allowed. If `directives` is not
- * provided then a default set of the built-in `[ @include, @skip ]` directives
- * will be used. If you wish to provide *additional* directives to these
- * built-ins, you must explicitly declare them. Example:
+ * provided then a default set of the specified directives (e.g. @include and
+ * @skip) will be used. If you wish to provide *additional* directives to these
+ * specified directives, you must explicitly declare them. Example:
  *
- *     directives: [
- *       myCustomDirective,
- *       GraphQLIncludeDirective,
- *       GraphQLSkipDirective
- *     ]
+ *     const MyAppSchema = new GraphQLSchema({
+ *       ...
+ *       directives: specifiedDirectives.concat([ myCustomDirective ]),
+ *     })
  *
  */
 export class GraphQLSchema {
@@ -104,11 +99,8 @@ export class GraphQLSchema {
       `Schema directives must be Array<GraphQLDirective> if provided but got: ${
         config.directives}.`
     );
-    // Provide `@include() and `@skip()` directives by default.
-    this._directives = config.directives || [
-      GraphQLIncludeDirective,
-      GraphQLSkipDirective
-    ];
+    // Provide specified directives (e.g. @include and @skip) by default.
+    this._directives = config.directives || specifiedDirectives;
 
     // Build type map now to detect any errors within this schema.
     let initialTypes: Array<?GraphQLType> = [

src/utilities/__tests__/buildASTSchema-test.js

@@ -15,6 +15,7 @@ import { buildASTSchema } from '../buildASTSchema';
 import {
   GraphQLSkipDirective,
   GraphQLIncludeDirective,
+  GraphQLDeprecatedDirective,
 } from '../../type/directives';
 
 /**
@@ -77,30 +78,37 @@ type Hello {
 }
 `;
     const schema = buildASTSchema(parse(body));
-    expect(schema.getDirectives().length).to.equal(2);
+    expect(schema.getDirectives().length).to.equal(3);
     expect(schema.getDirective('skip')).to.equal(GraphQLSkipDirective);
     expect(schema.getDirective('include')).to.equal(GraphQLIncludeDirective);
+    expect(
+      schema.getDirective('deprecated')
+    ).to.equal(GraphQLDeprecatedDirective);
   });
 
-  it('Overriding directives excludes built-ins', () => {
+  it('Overriding directives excludes specified', () => {
     const body = `
 schema {
   query: Hello
 }
 
 directive @skip on FIELD
 directive @include on FIELD
+directive @deprecated on FIELD_DEFINITION
 
 type Hello {
   str: String
 }
 `;
     const schema = buildASTSchema(parse(body));
-    expect(schema.getDirectives().length).to.equal(2);
+    expect(schema.getDirectives().length).to.equal(3);
     expect(schema.getDirective('skip')).to.not.equal(GraphQLSkipDirective);
     expect(
       schema.getDirective('include')
     ).to.not.equal(GraphQLIncludeDirective);
+    expect(
+      schema.getDirective('deprecated')
+    ).to.not.equal(GraphQLDeprecatedDirective);
   });
 
   it('Adding directives maintains @skip & @include', () => {
@@ -116,9 +124,10 @@ type Hello {
 }
 `;
     const schema = buildASTSchema(parse(body));
-    expect(schema.getDirectives().length).to.equal(3);
+    expect(schema.getDirectives().length).to.equal(4);
     expect(schema.getDirective('skip')).to.not.equal(undefined);
     expect(schema.getDirective('include')).to.not.equal(undefined);
+    expect(schema.getDirective('deprecated')).to.not.equal(undefined);
   });
 
   it('Type modifiers', () => {
@@ -453,6 +462,28 @@ type Query {
 }
 
 union Union = Concrete
+`;
+    const output = cycleOutput(body);
+    expect(output).to.equal(body);
+  });
+
+  it('Supports @deprecated', () => {
+    const body = `
+schema {
+  query: Query
+}
+
+enum MyEnum {
+  VALUE
+  OLD_VALUE @deprecated
+  OTHER_VALUE @deprecated(reason: "Terrible reasons")
+}
+
+type Query {
+  field1: String @deprecated
+  field2: Int @deprecated(reason: "Because I said so")
+  enum: MyEnum
+}
 `;
     const output = cycleOutput(body);
     expect(output).to.equal(body);

src/utilities/__tests__/schemaPrinter-test.js

@@ -7,6 +7,9 @@
  *  of patent rights can be found in the PATENTS file in the same directory.
  */
 
+// 80+ char lines are useful in describe/it, so ignore in this file.
+/* eslint-disable max-len */
+
 import { describe, it } from 'mocha';
 import { expect } from 'chai';
 import { printSchema, printIntrospectionSchema } from '../schemaPrinter';
@@ -602,14 +605,16 @@ directive @include(if: Boolean!) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT
 
 directive @skip(if: Boolean!) on FIELD | FRAGMENT_SPREAD | INLINE_FRAGMENT
 
+directive @deprecated(reason: String = "No longer supported") on FIELD_DEFINITION | ENUM_VALUE
+
 type __Directive {
   name: String!
   description: String
   locations: [__DirectiveLocation!]!
   args: [__InputValue!]!
-  onOperation: Boolean!
-  onFragment: Boolean!
-  onField: Boolean!
+  onOperation: Boolean! @deprecated(reason: "Use \`locations\`.")
+  onFragment: Boolean! @deprecated(reason: "Use \`locations\`.")
+  onField: Boolean! @deprecated(reason: "Use \`locations\`.")
 }
 
 enum __DirectiveLocation {

src/utilities/buildASTSchema.js

@@ -8,11 +8,14 @@
  *  of patent rights can be found in the PATENTS file in the same directory.
  */
 
+import find from '../jsutils/find';
 import invariant from '../jsutils/invariant';
 import keyMap from '../jsutils/keyMap';
 import keyValMap from '../jsutils/keyValMap';
 import { valueFromAST } from './valueFromAST';
 
+import { getArgumentValues } from '../execution/values';
+
 import {
   LIST_TYPE,
   NON_NULL_TYPE,
@@ -29,6 +32,7 @@ import {
 
 import type {
   Document,
+  Directive,
   Type,
   NamedType,
   SchemaDefinition,
@@ -64,6 +68,7 @@ import {
   GraphQLDirective,
   GraphQLSkipDirective,
   GraphQLIncludeDirective,
+  GraphQLDeprecatedDirective,
 } from '../type/directives';
 
 import {
@@ -224,7 +229,7 @@ export function buildASTSchema(ast: Document): GraphQLSchema {
 
   const directives = directiveDefs.map(getDirective);
 
-  // If skip and include were not explicitly declared, add them.
+  // If built-in directives were not explicitly declared, add them.
   if (!directives.some(directive => directive.name === 'skip')) {
     directives.push(GraphQLSkipDirective);
   }
@@ -233,6 +238,10 @@ export function buildASTSchema(ast: Document): GraphQLSchema {
     directives.push(GraphQLIncludeDirective);
   }
 
+  if (!directives.some(directive => directive.name === 'deprecated')) {
+    directives.push(GraphQLDeprecatedDirective);
+  }
+
   return new GraphQLSchema({
     query: getObjectType(astMap[queryTypeName]),
     mutation: mutationTypeName ? getObjectType(astMap[mutationTypeName]) : null,
@@ -321,6 +330,7 @@ export function buildASTSchema(ast: Document): GraphQLSchema {
       field => ({
         type: produceTypeDef(field.type),
         args: makeInputValues(field.arguments),
+        deprecationReason: getDeprecationReason(field.directives)
       })
     );
   }
@@ -353,7 +363,14 @@ export function buildASTSchema(ast: Document): GraphQLSchema {
   function makeEnumDef(def: EnumTypeDefinition) {
     const enumType = new GraphQLEnumType({
       name: def.name.value,
-      values: keyValMap(def.values, v => v.name.value, () => ({})),
+      values: keyValMap(
+        def.values,
+        enumValue => enumValue.name.value,
+        enumValue => ({
+          value: enumValue.name.value,
+          deprecationReason: getDeprecationReason(enumValue.directives)
+        })
+      ),
     });
 
     return enumType;
@@ -387,3 +404,18 @@ export function buildASTSchema(ast: Document): GraphQLSchema {
     });
   }
 }
+
+function getDeprecationReason(directives: ?Array<Directive>): ?string {
+  const deprecatedAST = directives && find(
+    directives,
+    directive => directive.name.value === GraphQLDeprecatedDirective.name
+  );
+  if (!deprecatedAST) {
+    return;
+  }
+  const { reason } = getArgumentValues(
+    GraphQLDeprecatedDirective.args,
+    deprecatedAST.arguments
+  );
+  return (reason: any);
+}