Enable '@typescript-eslint/switch-exhaustiveness-check' rule (graphql#3391)

Author: IvanGoncharov

.eslintrc.yml

@@ -538,7 +538,7 @@ overrides:
       '@typescript-eslint/restrict-template-expressions': off #TODO temporarily disabled
       '@typescript-eslint/sort-type-union-intersection-members': off # TODO consider
       '@typescript-eslint/strict-boolean-expressions': off # TODO consider
-      '@typescript-eslint/switch-exhaustiveness-check': off #TODO temporarily disabled
+      '@typescript-eslint/switch-exhaustiveness-check': error
       '@typescript-eslint/triple-slash-reference': error
       '@typescript-eslint/typedef': off
       '@typescript-eslint/unbound-method': off # TODO consider

src/__tests__/starWarsSchema.ts

@@ -1,5 +1,3 @@
-import { invariant } from '../jsutils/invariant';
-
 import { GraphQLSchema } from '../type/schema';
 import { GraphQLString } from '../type/scalars';
 import {
@@ -137,9 +135,6 @@ const characterInterface: GraphQLInterfaceType = new GraphQLInterfaceType({
       case 'Droid':
         return droidType.name;
     }
-
-    // istanbul ignore next (Not reachable. All possible types have been considered)
-    invariant(false);
   },
 });
 

src/execution/execute.ts

@@ -309,6 +309,8 @@ export function buildExecutionContext(
       case Kind.FRAGMENT_DEFINITION:
         fragments[definition.name.value] = definition;
         break;
+      default:
+      // ignore non-executable definitions
     }
   }
 

src/language/parser.ts

@@ -619,8 +619,9 @@ export class Parser {
           }
         }
         return this.parseVariable();
+      default:
+        throw this.unexpected();
     }
-    throw this.unexpected();
   }
 
   parseConstValueLiteral(): ConstValueNode {

src/type/schema.ts

@@ -9,10 +9,10 @@ import type { Maybe } from '../jsutils/Maybe';
 import type { GraphQLError } from '../error/GraphQLError';
 
 import type {
-  OperationTypeNode,
   SchemaDefinitionNode,
   SchemaExtensionNode,
 } from '../language/ast';
+import { OperationTypeNode } from '../language/ast';
 
 import type {
   GraphQLType,
@@ -282,11 +282,11 @@ export class GraphQLSchema {
 
   getRootType(operation: OperationTypeNode): Maybe<GraphQLObjectType> {
     switch (operation) {
-      case 'query':
+      case OperationTypeNode.QUERY:
         return this.getQueryType();
-      case 'mutation':
+      case OperationTypeNode.MUTATION:
         return this.getMutationType();
-      case 'subscription':
+      case OperationTypeNode.SUBSCRIPTION:
         return this.getSubscriptionType();
     }
   }

src/utilities/TypeInfo.ts

@@ -247,6 +247,8 @@ export class TypeInfo {
         this._enumValue = enumValue;
         break;
       }
+      default:
+      // Ignore other nodes
     }
   }
 
@@ -283,6 +285,8 @@ export class TypeInfo {
       case Kind.ENUM:
         this._enumValue = null;
         break;
+      default:
+      // Ignore other nodes
     }
   }
 }

src/utilities/__tests__/separateOperations-test.ts

@@ -201,6 +201,34 @@ describe('separateOperations', () => {
     });
   });
 
+  it('ignores type definitions', () => {
+    const ast = parse(`
+      query Foo {
+        ...Bar
+      }
+
+      fragment Bar on T {
+        baz
+      }
+
+      scalar Foo
+      type Bar
+    `);
+
+    const separatedASTs = mapValue(separateOperations(ast), print);
+    expect(separatedASTs).to.deep.equal({
+      Foo: dedent`
+        query Foo {
+          ...Bar
+        }
+
+        fragment Bar on T {
+          baz
+        }
+      `,
+    });
+  });
+
   it('handles unknown fragments', () => {
     const ast = parse(`
       {

src/utilities/buildClientSchema.ts

@@ -173,6 +173,8 @@ export function buildClientSchema(
   function buildType(type: IntrospectionType): GraphQLNamedType {
     // eslint-disable-next-line @typescript-eslint/prefer-optional-chain
     if (type != null && type.name != null && type.kind != null) {
+      // FIXME: Properly type IntrospectionType, it's a breaking change so fix in v17
+      // eslint-disable-next-line @typescript-eslint/switch-exhaustiveness-check
       switch (type.kind) {
         case TypeKind.SCALAR:
           return buildScalarDef(type);

src/utilities/extendSchema.ts

@@ -649,9 +649,6 @@ export function extendSchemaImpl(
         });
       }
     }
-
-    // istanbul ignore next (Not reachable. All possible type definition nodes have been considered)
-    invariant(false, 'Unexpected type definition node: ' + inspect(astNode));
   }
 }
 

src/utilities/separateOperations.ts

@@ -31,6 +31,8 @@ export function separateOperations(
           definitionNode.selectionSet,
         );
         break;
+      default:
+      // ignore non-executable definitions
     }
   }