enable TypeScript strictNullChecks

src/core/ObservableQuery.ts

@@ -126,7 +126,10 @@ export class ObservableQuery<T> extends Observable<ApolloQueryResult<T>> {
     const { data, partial } = this.queryManager.getCurrentQueryResult(this, true);
     const queryStoreValue = this.queryManager.getApolloState().queries[this.queryId];
 
-    if (queryStoreValue && (queryStoreValue.graphQLErrors || queryStoreValue.networkError)) {
+    if (queryStoreValue && (
+      (queryStoreValue.graphQLErrors && queryStoreValue.graphQLErrors.length > 0) ||
+      queryStoreValue.networkError
+    )) {
       const error = new ApolloError({
         graphQLErrors: queryStoreValue.graphQLErrors,
         networkError: queryStoreValue.networkError,

src/core/QueryManager.ts

@@ -342,7 +342,10 @@ export class QueryManager {
 
         // If we have either a GraphQL error or a network error, we create
         // an error and tell the observer about it.
-        if (queryStoreValue.graphQLErrors || queryStoreValue.networkError) {
+        if (
+          (queryStoreValue.graphQLErrors && queryStoreValue.graphQLErrors.length > 0) ||
+          queryStoreValue.networkError
+        ) {
           const apolloError = new ApolloError({
             graphQLErrors: queryStoreValue.graphQLErrors,
             networkError: queryStoreValue.networkError,

src/core/types.ts

@@ -40,4 +40,4 @@ export enum FetchType {
   poll = 3,
 }
 
-export type IdGetter = (value: Object) => string;
+export type IdGetter = (value: Object) => string | null | undefined;

src/data/storeUtils.ts

@@ -138,7 +138,7 @@ export interface JsonValue {
   json: any;
 }
 
-export type StoreValue = number | string | string[] | IdValue | JsonValue | void;
+export type StoreValue = number | string | string[] | IdValue | JsonValue | null | undefined | void;
 
 export function isIdValue(idObject: StoreValue): idObject is IdValue {
   return (

src/data/writeToStore.ts

@@ -61,7 +61,7 @@ export function writeQueryToStore({
   query,
   store = {} as NormalizedCache,
   variables,
-  dataIdFromObject = null,
+  dataIdFromObject,
   fragmentMap = {} as FragmentMap,
 }: {
   result: Object,
@@ -99,7 +99,7 @@ export function writeResultToStore({
   document,
   store = {} as NormalizedCache,
   variables,
-  dataIdFromObject = null,
+  dataIdFromObject,
 }: {
   dataId: string,
   result: any,
@@ -172,7 +172,7 @@ export function writeSelectionSetToStore({
         fragment = selection;
       } else {
         // Named fragment
-        fragment = fragmentMap[selection.name.value];
+        fragment = (fragmentMap || {})[selection.name.value];
 
         if (!fragment) {
           throw new Error(`No fragment named ${selection.name.value}.`);
@@ -236,7 +236,7 @@ function writeFieldToStore({
   // specifies if we need to merge existing keys in the store
   let shouldMerge = false;
   // If we merge, this will be the generatedKey
-  let generatedKey: string;
+  let generatedKey: string = '';
 
   // If this is a scalar value...
   if (!field.selectionSet || value === null) {

src/errors/ApolloError.ts

@@ -33,7 +33,7 @@ import { GraphQLError } from 'graphql';
 export class ApolloError extends Error {
   public message: string;
   public graphQLErrors: GraphQLError[];
-  public networkError: Error;
+  public networkError: Error | null;
 
   // An object that can be used to provide some additional information
   // about an error, e.g. specifying the type of error this is. Used
@@ -50,13 +50,13 @@ export class ApolloError extends Error {
     extraInfo,
   }: {
     graphQLErrors?: GraphQLError[],
-    networkError?: Error,
+    networkError?: Error | null,
     errorMessage?: string,
     extraInfo?: any,
   }) {
     super(errorMessage);
-    this.graphQLErrors = graphQLErrors;
-    this.networkError = networkError;
+    this.graphQLErrors = graphQLErrors || [];
+    this.networkError = networkError || null;
 
     // set up the stack trace
     this.stack = new Error().stack;

src/mutations/store.ts

@@ -18,7 +18,7 @@ export interface MutationStoreValue {
   mutationString: string;
   variables: Object;
   loading: boolean;
-  error: Error;
+  error: Error | null;
 }
 
 export interface SelectionSetWithRoot {

src/queries/directives.ts

@@ -7,11 +7,7 @@ import {
 } from 'graphql';
 
 
-export function shouldInclude(selection: SelectionNode, variables?: { [name: string]: any }): boolean {
-  if (!variables) {
-    variables = {};
-  }
-
+export function shouldInclude(selection: SelectionNode, variables: { [name: string]: any } = {}): boolean {
   if (!selection.directives) {
     return true;
   }
@@ -25,19 +21,19 @@ export function shouldInclude(selection: SelectionNode, variables?: { [name: str
     }
 
     //evaluate the "if" argument and skip (i.e. return undefined) if it evaluates to true.
-    const directiveArguments = directive.arguments;
+    const directiveArguments = directive.arguments || [];
     const directiveName = directive.name.value;
     if (directiveArguments.length !== 1) {
       throw new Error(`Incorrect number of arguments for the @${directiveName} directive.`);
     }
 
 
-    const ifArgument = directive.arguments[0];
+    const ifArgument = directiveArguments[0];
     if (!ifArgument.name || ifArgument.name.value !== 'if') {
       throw new Error(`Invalid argument for the @${directiveName} directive.`);
     }
 
-    const ifValue = directive.arguments[0].value;
+    const ifValue = directiveArguments[0].value;
     let evaledValue: boolean = false;
     if (!ifValue || ifValue.kind !== 'BooleanValue') {
       // means it has to be a variable value if this is a valid @skip or @include directive

src/queries/getFromAST.ts

@@ -8,7 +8,7 @@ import {
 export function getMutationDefinition(doc: DocumentNode): OperationDefinitionNode {
   checkDocument(doc);
 
-  let mutationDef: OperationDefinitionNode = null;
+  let mutationDef: OperationDefinitionNode | null = null;
   doc.definitions.forEach((definition) => {
     if (definition.kind === 'OperationDefinition'
         && (definition as OperationDefinitionNode).operation === 'mutation') {
@@ -55,9 +55,8 @@ string in a "gql" tag? http://docs.apollostack.com/apollo-client/core.html#gql`)
 export function getOperationName(doc: DocumentNode): string {
   let res: string = '';
   doc.definitions.forEach((definition) => {
-    if (definition.kind === 'OperationDefinition'
-        && (definition as OperationDefinitionNode).name) {
-      res = (definition as OperationDefinitionNode).name.value;
+    if (definition.kind === 'OperationDefinition' && definition.name) {
+      res = definition.name.value;
     }
   });
   return res;
@@ -79,7 +78,7 @@ export function getFragmentDefinitions(doc: DocumentNode): FragmentDefinitionNod
 export function getQueryDefinition(doc: DocumentNode): OperationDefinitionNode {
   checkDocument(doc);
 
-  let queryDef: OperationDefinitionNode = null;
+  let queryDef: OperationDefinitionNode | null = null;
   doc.definitions.map((definition) => {
     if (definition.kind === 'OperationDefinition'
        && (definition as OperationDefinitionNode).operation === 'query') {
@@ -98,7 +97,7 @@ export function getQueryDefinition(doc: DocumentNode): OperationDefinitionNode {
 export function getOperationDefinition(doc: DocumentNode): OperationDefinitionNode {
   checkDocument(doc);
 
-  let opDef: OperationDefinitionNode = null;
+  let opDef: OperationDefinitionNode | null = null;
   doc.definitions.map((definition) => {
     if (definition.kind === 'OperationDefinition') {
       opDef = definition as OperationDefinitionNode;

src/queries/queryTransform.ts

@@ -15,7 +15,6 @@ import { cloneDeep } from '../util/cloneDeep';
 
 const TYPENAME_FIELD: FieldNode = {
   kind: 'Field',
-  alias: null,
   name: {
     kind: 'Name',
     value: '__typename',
@@ -26,7 +25,7 @@ function addTypenameToSelectionSet(
   selectionSet: SelectionSetNode,
   isRoot = false,
 ) {
-  if (selectionSet && selectionSet.selections) {
+  if (selectionSet.selections) {
     if (! isRoot) {
       const alreadyHasThisField = selectionSet.selections.some((selection) => {
         return selection.kind === 'Field' && (selection as FieldNode).name.value === '__typename';
@@ -39,7 +38,9 @@ function addTypenameToSelectionSet(
 
     selectionSet.selections.forEach((selection) => {
       if (selection.kind === 'Field' || selection.kind === 'InlineFragment') {
-        addTypenameToSelectionSet((selection as FieldNode | InlineFragmentNode).selectionSet);
+        if (selection.selectionSet) {
+          addTypenameToSelectionSet(selection.selectionSet);
+        }
       }
     });
   }

src/queries/store.ts

@@ -31,9 +31,9 @@ export type QueryStoreValue = {
   queryString: string;
   document: DocumentNode;
   variables: Object;
-  previousVariables: Object;
+  previousVariables: Object | null;
   networkStatus: NetworkStatus;
-  networkError: Error;
+  networkError: Error | null;
   graphQLErrors: GraphQLError[];
   forceFetch: boolean;
   returnPartialData: boolean;
@@ -65,7 +65,7 @@ export function queries(
 
     let isSetVariables = false;
 
-    let previousVariables: Object;
+    let previousVariables: Object | null = null;
     if (
       action.storePreviousVariables &&
       previousQuery &&
@@ -101,7 +101,7 @@ export function queries(
       variables: action.variables,
       previousVariables,
       networkError: null,
-      graphQLErrors: null,
+      graphQLErrors: [],
       networkStatus: newNetworkStatus,
       forceFetch: action.forceFetch,
       returnPartialData: action.returnPartialData,
@@ -166,7 +166,7 @@ export function queries(
       // and do not need to hit the server. Not sure when we'd fire this action if the result is not complete, so that bears explanation.
       // We should write that down somewhere.
       networkStatus: action.complete ? NetworkStatus.ready : NetworkStatus.loading,
-    } as QueryStoreValue;
+    };
 
     return newState;
   } else if (isQueryStopAction(action)) {

src/scheduler/scheduler.ts

@@ -73,7 +73,7 @@ export class QueryScheduler {
 
   public startPollingQuery<T>(
     options: WatchQueryOptions,
-    queryId?: string,
+    queryId: string,
     listener?: QueryListener,
   ): string {
     if (!options.pollInterval) {
@@ -135,6 +135,10 @@ export class QueryScheduler {
   public addQueryOnInterval<T>(queryId: string, queryOptions: WatchQueryOptions) {
     const interval = queryOptions.pollInterval;
 
+    if (!interval) {
+      throw new Error(`A poll interval is required to start polling query with id '${queryId}'.`);
+    }
+
     // If there are other queries on this interval, this query will just fire with those
     // and we don't need to create a new timer.
     if (this.intervalQueries.hasOwnProperty(interval.toString()) && this.intervalQueries[interval].length > 0) {

src/transport/batchedNetworkInterface.ts

@@ -141,5 +141,5 @@ export function createBatchingNetworkInterface(options: BatchingNetworkInterface
   if (! options) {
     throw new Error('You must pass an options argument to createNetworkInterface.');
   }
-  return new HTTPBatchedNetworkInterface(options.uri, options.batchInterval, options.opts);
+  return new HTTPBatchedNetworkInterface(options.uri, options.batchInterval, options.opts || {});
 }

src/transport/batching.ts

@@ -54,7 +54,7 @@ export class QueryBatcher {
 
   // Consumes the queue. Called on a polling interval.
   // Returns a list of promises (one for each query).
-  public consumeQueue(): Promise<ExecutionResult>[] | undefined {
+  public consumeQueue(): (Promise<ExecutionResult> | undefined)[] | undefined {
     if (this.queuedRequests.length < 1) {
       return undefined;
     }
@@ -67,7 +67,7 @@ export class QueryBatcher {
       };
     });
 
-    const promises: Promise<ExecutionResult>[] = [];
+    const promises: (Promise<ExecutionResult> | undefined)[] = [];
     const resolvers: any[] = [];
     const rejecters: any[] = [];
     this.queuedRequests.forEach((fetchRequest, index) => {

src/transport/networkInterface.ts

@@ -88,7 +88,7 @@ export class HTTPFetchNetworkInterface implements NetworkInterface {
   public _middlewares: MiddlewareInterface[];
   public _afterwares: AfterwareInterface[];
 
-  constructor(uri: string, opts: RequestInit = {}) {
+  constructor(uri: string | undefined, opts: RequestInit = {}) {
     if (!uri) {
       throw new Error('A remote endpoint is required for a network layer');
     }
@@ -112,7 +112,9 @@ export class HTTPFetchNetworkInterface implements NetworkInterface {
         const next = () => {
           if (funcs.length > 0) {
             const f = funcs.shift();
-            f.applyMiddleware.apply(scope, [{ request, options }, next]);
+            if (f) {
+              f.applyMiddleware.apply(scope, [{ request, options }, next]);
+            }
           } else {
             resolve({
               request,
@@ -229,19 +231,19 @@ export function createNetworkInterface(
     throw new Error('You must pass an options argument to createNetworkInterface.');
   }
 
-  let uri: string;
-  let opts: RequestInit;
+  let uri: string | undefined;
+  let opts: RequestInit | undefined;
 
   // We want to change the API in the future so that you just pass all of the options as one
   // argument, so even though the internals work with two arguments we're warning here.
   if (typeof uriOrInterfaceOpts === 'string') {
     console.warn(`Passing the URI as the first argument to createNetworkInterface is deprecated \
 as of Apollo Client 0.5. Please pass it as the "uri" property of the network interface options.`);
     opts = secondArgOpts;
-    uri = uriOrInterfaceOpts as string;
+    uri = uriOrInterfaceOpts;
   } else {
-    opts = (uriOrInterfaceOpts as NetworkInterfaceOptions).opts;
-    uri = (uriOrInterfaceOpts as NetworkInterfaceOptions).uri;
+    opts = uriOrInterfaceOpts.opts;
+    uri = uriOrInterfaceOpts.uri;
   }
   return new HTTPFetchNetworkInterface(uri, opts);
 }

test/ObservableQuery.ts

@@ -256,8 +256,8 @@ describe('ObservableQuery', () => {
     });
 
     it('does a network request if noFetch becomes true then store is reset then noFetch becomes false', (done) => {
-      let queryManager: QueryManager = null;
-      let observable: ObservableQuery<any> = null;
+      let queryManager: QueryManager;
+      let observable: ObservableQuery<any>;
       const testQuery = gql`
         query {
           author {
@@ -309,8 +309,8 @@ describe('ObservableQuery', () => {
     });
 
     it('does a network request if noFetch becomes false', (done) => {
-      let queryManager: QueryManager = null;
-      let observable: ObservableQuery<any> = null;
+      let queryManager: QueryManager;
+      let observable: ObservableQuery<any>;
       const testQuery = gql`
         query {
           author {
@@ -637,7 +637,7 @@ describe('ObservableQuery', () => {
           const currentResult = observable.currentResult();
 
           assert.equal(currentResult.loading, false);
-          assert.deepEqual(currentResult.error.graphQLErrors, [error]);
+          assert.deepEqual(currentResult.error!.graphQLErrors, [error]);
         });
     });