enable strict mode

src/__tests__/starWarsData.ts

@@ -6,7 +6,7 @@
  * JSON objects in a more complex demo.
  */
 
-interface Ship {
+export interface Ship {
   id: string;
   name: string;
 }
@@ -25,7 +25,7 @@ const allShips: Array<Ship> = [
   { id: '8', name: 'Executor' },
 ];
 
-interface Faction {
+export interface Faction {
   id: string;
   name: string;
   ships: Array<string>;

src/__tests__/starWarsSchema.ts

@@ -128,7 +128,7 @@ const { nodeInterface, nodeField } = nodeDefinitions(
  *     name: String
  *   }
  */
-const shipType = new GraphQLObjectType({
+const shipType: GraphQLObjectType = new GraphQLObjectType({
   name: 'Ship',
   description: 'A ship in the Star Wars saga',
   interfaces: [nodeInterface],
@@ -171,7 +171,7 @@ const { connectionType: shipConnection } = connectionDefinitions({
  *     ships: ShipConnection
  *   }
  */
-const factionType = new GraphQLObjectType({
+const factionType: GraphQLObjectType = new GraphQLObjectType({
   name: 'Faction',
   description: 'A faction in the Star Wars saga',
   interfaces: [nodeInterface],

src/connection/__tests__/connection-test.ts

@@ -29,7 +29,7 @@ const allUsers = [
   { name: 'Tim', friends: [0, 1, 2, 3] },
 ];
 
-const userType = new GraphQLObjectType({
+const userType: GraphQLObjectType = new GraphQLObjectType({
   name: 'User',
   fields: () => ({
     name: {

src/connection/connection.ts

@@ -26,16 +26,17 @@ export interface ForwardConnectionArgs {
  * Returns a GraphQLFieldConfigArgumentMap appropriate to include on a field
  * whose return type is a connection type with forward pagination.
  */
-export const forwardConnectionArgs:
-  | ForwardConnectionArgs
-  | GraphQLFieldConfigArgumentMap = {
+export const forwardConnectionArgs: ForwardConnectionArgs &
+  GraphQLFieldConfigArgumentMap = {
   after: {
     type: GraphQLString,
+    // @ts-expect-error FIXME
     description:
       'Returns the items in the list that come after the specified cursor.',
   },
   first: {
     type: GraphQLInt,
+    // @ts-expect-error FIXME
     description: 'Returns the first n items from the list.',
   },
 };
@@ -53,11 +54,13 @@ export const backwardConnectionArgs: BackwardConnectionArgs &
   GraphQLFieldConfigArgumentMap = {
   before: {
     type: GraphQLString,
+    // @ts-expect-error FIXME
     description:
       'Returns the items in the list that come before the specified cursor.',
   },
   last: {
     type: GraphQLInt,
+    // @ts-expect-error FIXME
     description: 'Returns the last n items from the list.',
   },
 };

src/mutation/type.d.ts

@@ -0,0 +1 @@
+declare module 'graphql/jsutils/isPromise';

src/node/__tests__/global-test.ts

@@ -72,7 +72,7 @@ const { nodeField, nodeInterface } = nodeDefinitions(
   },
 );
 
-const userType = new GraphQLObjectType({
+const userType: GraphQLObjectType = new GraphQLObjectType({
   name: 'User',
   interfaces: [nodeInterface],
   fields: () => ({
@@ -83,7 +83,7 @@ const userType = new GraphQLObjectType({
   }),
 });
 
-const photoType = new GraphQLObjectType({
+const photoType: GraphQLObjectType = new GraphQLObjectType({
   name: 'Photo',
   interfaces: [nodeInterface],
   fields: () => ({
@@ -94,7 +94,7 @@ const photoType = new GraphQLObjectType({
   }),
 });
 
-const postType = new GraphQLObjectType({
+const postType: GraphQLObjectType = new GraphQLObjectType({
   name: 'Post',
   interfaces: [nodeInterface],
   fields: () => ({

src/node/__tests__/node-test.ts

@@ -57,7 +57,7 @@ const { nodeField, nodesField, nodeInterface } = nodeDefinitions(
   },
 );
 
-const userType = new GraphQLObjectType({
+const userType: GraphQLObjectType = new GraphQLObjectType({
   name: 'User',
   interfaces: [nodeInterface],
   fields: () => ({
@@ -70,7 +70,7 @@ const userType = new GraphQLObjectType({
   }),
 });
 
-const photoType = new GraphQLObjectType({
+const photoType: GraphQLObjectType = new GraphQLObjectType({
   name: 'Photo',
   interfaces: [nodeInterface],
   fields: () => ({

src/node/__tests__/nodeAsync-test.ts

@@ -28,7 +28,7 @@ const { nodeField, nodeInterface } = nodeDefinitions(
   () => userType,
 );
 
-const userType = new GraphQLObjectType({
+const userType: GraphQLObjectType = new GraphQLObjectType({
   name: 'User',
   interfaces: [nodeInterface],
   fields: () => ({

src/node/node.ts

@@ -49,7 +49,7 @@ export function nodeDefinitions<TContext>(
     resolveType: typeResolver,
   });
 
-  const nodeField = {
+  const nodeField: GraphQLFieldConfig<unknown, TContext> = {
     description: 'Fetches an object given its ID',
     type: nodeInterface,
     args: {
@@ -61,7 +61,7 @@ export function nodeDefinitions<TContext>(
     resolve: (_obj, { id }, context, info) => fetchById(id, context, info),
   };
 
-  const nodesField = {
+  const nodesField: GraphQLFieldConfig<unknown, TContext> = {
     description: 'Fetches objects given their IDs',
     type: new GraphQLNonNull(new GraphQLList(nodeInterface)),
     args: {
@@ -73,7 +73,7 @@ export function nodeDefinitions<TContext>(
       },
     },
     resolve: (_obj, { ids }, context, info) =>
-      ids.map((id) => fetchById(id, context, info)),
+      ids.map((id: string) => fetchById(id, context, info)),
   };
 
   return { nodeInterface, nodeField, nodesField };

src/node/plural.ts

@@ -36,7 +36,7 @@ export function pluralIdentifyingRootField(
     },
     resolve(_obj, args, context, info) {
       const inputs = args[config.argName];
-      return inputs.map((input) =>
+      return inputs.map((input: unknown) =>
         config.resolveSingleInput(input, context, info),
       );
     },

src/utils/base64.ts

@@ -100,7 +100,8 @@ function fromBase64Char(base64Char: string | undefined): number {
 function stringToUTF8Array(input: string): Array<number> {
   const result = [];
   for (const utfChar of input) {
-    const code = utfChar.codePointAt(0);
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const code = utfChar.codePointAt(0)!;
     if (code < 0x80) {
       result.push(code);
     } else if (code < 0x800) {

tsconfig.json

@@ -4,10 +4,7 @@
     "module": "commonjs",
     "lib": ["es2019", "es2020.promise", "es2020.bigint", "es2020.string"],
     "target": "es2019",
-    "noImplicitAny": false,
-    "noImplicitThis": false,
-    "strictNullChecks": false,
-    "strictFunctionTypes": false,
+    "strict": true,
     "noEmit": true,
     "isolatedModules": true,
     "forceConsistentCasingInFileNames": true