feat: add a check for deprecation errors

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Change log
 ### vNEXT
+- Add new rule `no-deprecated-fields` in [Kristján Oddsson](https://github.com/koddsson/)[#92](https://github.com/apollographql/eslint-plugin-graphql/pull/93)
 
 ### v1.4.1
 Skipped v1.4.0 because of incorrect version tag in `package.json`

README.md

@@ -21,7 +21,7 @@ If you want to lint your GraphQL schema, rather than queries, check out [cjoudre
 
 ### Importing schema JSON
 
-You'll need to import your [introspection query result](https://github.com/graphql/graphql-js/blob/master/src/utilities/introspectionQuery.js) or the schema as a string in the Schema Language format. This can be done if you define your ESLint config in a JS file. 
+You'll need to import your [introspection query result](https://github.com/graphql/graphql-js/blob/master/src/utilities/introspectionQuery.js) or the schema as a string in the Schema Language format. This can be done if you define your ESLint config in a JS file.
 
 ### Retrieving a remote GraphQL schema
 
@@ -502,3 +502,47 @@ module.exports = {
   ]
 }
 ```
+
+### No Deprecated Fields Validation Rule
+
+The No Deprecated Fields rule validates that no deprecated fields are part of the query. This is useful to discover fields that have been marked as deprecated and shouldn't be used.
+
+**Fail**
+```
+// 'id' requested and marked as deprecated in the schema
+
+schema {
+  query {
+    viewer {
+      id: Int @deprecated(reason: "Use the 'uuid' field instead")
+      uuid: String
+    }
+  }
+}
+
+query ViewerName {
+  viewer {
+    id
+  }
+}
+```
+
+The rule is defined as `graphql/no-deprecated-fields`.
+
+```js
+// In a file called .eslintrc.js
+module.exports = {
+  rules: {
+    'graphql/no-deprecated-fields': [
+      'error',
+      {
+        env: 'relay',
+        schemaJson: require('./schema.json')
+      },
+    ],
+  },
+  plugins: [
+    'graphql'
+  ]
+}
+```

src/index.js

@@ -4,7 +4,7 @@ import {
   validate,
   buildClientSchema,
   buildSchema,
-  specifiedRules as allGraphQLValidators,
+  specifiedRules as allGraphQLValidators
 } from 'graphql';
 
 import {
@@ -222,6 +222,24 @@ export const rules = {
       }));
     },
   },
+  'no-deprecated-fields': {
+    meta: {
+      schema: {
+        type: 'array',
+        items: {
+          additionalProperties: false,
+          properties: { ...defaultRuleProperties },
+          ...schemaPropsExclusiveness,
+        },
+      },
+    },
+    create: (context) => {
+      return createRule(context, (optionGroup) => parseOptions({
+        validators: ['noDeprecatedFields'],
+        ...optionGroup,
+      }));
+    },
+  },
 };
 
 function parseOptions(optionGroup) {

src/rules.js

@@ -58,3 +58,36 @@ export function typeNamesShouldBeCapitalized(context) {
     }
   }
 }
+
+export function noDeprecatedFields(context) {
+  return {
+    Field(node) {
+      const fieldDef = context.getFieldDef();
+      if (fieldDef && fieldDef.isDeprecated) {
+        const parentType = context.getParentType();
+        if (parentType) {
+          const reason = fieldDef.deprecationReason;
+          context.reportError(new GraphQLError(
+            `The field ${parentType.name}.${fieldDef.name} is deprecated.` +
+            (reason ? ' ' + reason : ''),
+            [ node ]
+          ));
+        }
+      }
+    },
+    EnumValue(node) {
+      const enumVal = context.getEnumValue();
+      if (enumVal && enumVal.isDeprecated) {
+        const type = getNamedType(context.getInputType());
+        if (type) {
+          const reason = enumVal.deprecationReason;
+          errors.push(new GraphQLError(
+            `The enum value ${type.name}.${enumVal.name} is deprecated.` +
+            (reason ? ' ' + reason : ''),
+            [ node ]
+          ));
+        }
+      }
+    }
+  }
+}

test/makeRule.js

@@ -427,6 +427,7 @@ const parserOptions = {
             greetings: () => Relay.QL\`
               fragment on Greetings {
                 hello,
+                hi,
               }
             \`,
           }
@@ -526,7 +527,6 @@ const parserOptions = {
           column: 19
         }]
       },
-
       // Example from issue report:
       // https://github.com/apollostack/eslint-plugin-graphql/issues/12#issuecomment-215445880
       {
@@ -914,6 +914,48 @@ const typeNameCapValidatorCases = {
     },
   ]
 };
+
+const noDeprecatedFieldsCases = {
+  pass: [
+    `
+      @relay({
+        fragments: {
+          greetings: () => Relay.QL\`
+            fragment on Greetings {
+              hello,
+            }
+          \`,
+        }
+      })
+      class HelloApp extends React.Component {}
+    `
+  ],
+  fail: [
+    {
+      options,
+      parser: 'babel-eslint',
+      code: `
+        @relay({
+          fragments: {
+            greetings: () => Relay.QL\`
+              fragment on Greetings {
+                hi,
+              }
+            \`,
+          }
+        })
+        class HelloApp extends React.Component {}
+      `,
+      errors: [{
+        message: "The field Greetings.hi is deprecated. Please use the more formal greeting 'hello'",
+        type: 'TaggedTemplateExpression',
+        line: 6,
+        column: 17
+      }]
+    }
+  ]
+};
+
 {
   let options = [{
     schemaJson, tagName: 'gql',
@@ -1000,3 +1042,14 @@ ruleTester.run('testing capitalized-type-name rule', rules['capitalized-type-nam
   valid: typeNameCapValidatorCases.pass.map((code) => ({options, parserOptions, code})),
   invalid: typeNameCapValidatorCases.fail.map(({code, errors}) => ({options, parserOptions, code, errors})),
 });
+
+options = [
+  {
+    schemaJson,
+    env: 'relay',
+  },
+];
+ruleTester.run('testing no-deprecated-fields rule', rules['no-deprecated-fields'], {
+  valid: noDeprecatedFieldsCases.pass.map((code) => ({options, parser: 'babel-eslint', code})),
+  invalid: noDeprecatedFieldsCases.fail.map(({code, errors}) => ({options, parser: 'babel-eslint', code, errors})),
+});

test/schema.graphql

@@ -45,6 +45,7 @@ type Film {
 type Greetings {
   id: ID
   hello: String
+  hi: String @deprecated(reason: "Please use the more formal greeting 'hello'")
 }
 
 type Story {