Turn on Typescript strict option for Firestore

packages/firestore/src/api/credentials.ts

@@ -134,7 +134,7 @@ export class FirebaseCredentialsProvider implements CredentialsProvider {
   private tokenListener: ((token: string | null) => void) | null = null;
 
   /** Tracks the current User. */
-  private currentUser: User;
+  private currentUser?: User;
 
   /**
    * Counter used to detect if the token changed while a getToken request was
@@ -192,7 +192,7 @@ export class FirebaseCredentialsProvider implements CredentialsProvider {
               typeof tokenData.accessToken === 'string',
               'Invalid tokenData returned from getToken():' + tokenData
             );
-            return new OAuthToken(tokenData.accessToken, this.currentUser);
+            return new OAuthToken(tokenData.accessToken, this.currentUser!);
           } else {
             return null;
           }

packages/firestore/src/api/database.ts

@@ -283,12 +283,12 @@ class FirestoreSettings {
 }
 
 class FirestoreConfig {
-  databaseId: DatabaseId;
-  persistenceKey: string;
-  credentials: CredentialsProvider;
-  firebaseApp: FirebaseApp;
-  settings: FirestoreSettings;
-  persistence: boolean;
+  databaseId!: DatabaseId;
+  persistenceKey!: string;
+  credentials!: CredentialsProvider;
+  firebaseApp?: FirebaseApp;
+  settings!: FirestoreSettings;
+  persistence?: boolean;
 }
 
 /**
@@ -313,7 +313,7 @@ export class Firestore implements firestore.FirebaseFirestore, FirebaseService {
   // TODO(mikelehen): Use modularized initialization instead.
   readonly _queue = new AsyncQueue();
 
-  _dataConverter: UserDataConverter;
+  _dataConverter!: UserDataConverter;
 
   constructor(databaseIdOrApp: FirestoreDatabase | FirebaseApp) {
     const config = new FirestoreConfig();

packages/firestore/src/core/event_manager.ts

@@ -28,8 +28,8 @@ import { DocumentViewChange, ChangeType, ViewSnapshot } from './view_snapshot';
  * tracked by EventManager.
  */
 class QueryListenersInfo {
-  viewSnap: ViewSnapshot | null;
-  targetId: TargetId;
+  viewSnap: ViewSnapshot | null = null;
+  targetId?: TargetId;
   listeners: QueryListener[] = [];
 }
 
@@ -81,7 +81,7 @@ export class EventManager implements SyncEngineListener {
         return targetId;
       });
     } else {
-      return Promise.resolve(queryInfo.targetId);
+      return Promise.resolve(queryInfo.targetId!);
     }
   }
 
@@ -166,7 +166,7 @@ export class QueryListener {
 
   private options: ListenOptions;
 
-  private snap: ViewSnapshot;
+  private snap?: ViewSnapshot;
 
   private onlineState: OnlineState = OnlineState.Unknown;
 

packages/firestore/src/core/firestore_client.ts

@@ -96,21 +96,20 @@ export class FirestoreClient {
   // NOTE: These should technically have '|undefined' in the types, since
   // they're initialized asynchronously rather than in the constructor, but
   // given that all work is done on the async queue and we assert that
-  // initialization completes before any other work is queued, we're cheating
-  // with the types rather than littering the code with '!' or unnecessary
-  // undefined checks.
-  private eventMgr: EventManager;
-  private persistence: Persistence;
-  private localStore: LocalStore;
-  private remoteStore: RemoteStore;
-  private syncEngine: SyncEngine;
+  // initialization completes before any other work is queued, we use !
+  // to guarantee these will be initialized when called.
+  private eventMgr!: EventManager;
+  private persistence!: Persistence;
+  private localStore!: LocalStore;
+  private remoteStore!: RemoteStore;
+  private syncEngine!: SyncEngine;
   private lruScheduler?: LruScheduler;
 
   private readonly clientId = AutoId.newId();
   private _clientShutdown = false;
 
   // PORTING NOTE: SharedClientState is only used for multi-tab web.
-  private sharedClientState: SharedClientState;
+  private sharedClientState!: SharedClientState;
 
   constructor(
     private platform: Platform,

packages/firestore/src/core/sync_engine.ts

@@ -109,7 +109,7 @@ class LimboResolution {
    * decide whether it needs to manufacture a delete event for the target once
    * the target is CURRENT.
    */
-  receivedDocument: boolean;
+  receivedDocument: boolean = false;
 }
 
 /**

packages/firestore/src/core/target_id_generator.ts

@@ -42,7 +42,8 @@ enum GeneratorIds {
 // TODO(mrschmidt): Explore removing this class in favor of generating these IDs
 // directly in SyncEngine and LocalStore.
 export class TargetIdGenerator {
-  private nextId: TargetId;
+  // This is assigned in this.seek(), which is called in the constructor.
+  private nextId!: TargetId;
 
   /**
    * Instantiates a new TargetIdGenerator. If a seed is provided, the generator

packages/firestore/src/local/indexeddb_persistence.ts

@@ -236,23 +236,23 @@ export class IndexedDbPersistence implements Persistence {
   private readonly document: Document | null;
   private readonly window: Window;
 
-  private simpleDb: SimpleDb;
+  private simpleDb!: SimpleDb;
   private _started = false;
   private isPrimary = false;
   private networkEnabled = true;
   private dbName: string;
 
   /** Our window.unload handler, if registered. */
-  private windowUnloadHandler: (() => void) | null;
+  private windowUnloadHandler: (() => void) | null = null;
   private inForeground = false;
 
   private serializer: LocalSerializer;
 
   /** Our 'visibilitychange' listener if registered. */
-  private documentVisibilityHandler: ((e?: Event) => void) | null;
+  private documentVisibilityHandler: ((e?: Event) => void) | null = null;
 
   /** The client metadata refresh task. */
-  private clientMetadataRefresher: CancelablePromise<void>;
+  private clientMetadataRefresher?: CancelablePromise<void>;
 
   /** The last time we garbage collected the Remote Document Changelog. */
   private lastGarbageCollectionTime = Number.NEGATIVE_INFINITY;
@@ -267,7 +267,7 @@ export class IndexedDbPersistence implements Persistence {
   private readonly indexManager: IndexedDbIndexManager;
   private readonly remoteDocumentCache: IndexedDbRemoteDocumentCache;
   private readonly webStorage: Storage;
-  private listenSequence: ListenSequence;
+  private listenSequence!: ListenSequence;
   readonly referenceDelegate: IndexedDbLruDelegate;
 
   // Note that `multiClientParams` must be present to enable multi-client support while multi-tab
@@ -1131,7 +1131,7 @@ function clientMetadataStore(
 
 /** Provides LRU functionality for IndexedDB persistence. */
 export class IndexedDbLruDelegate implements ReferenceDelegate, LruDelegate {
-  private inMemoryPins: ReferenceSet | null;
+  private inMemoryPins: ReferenceSet | null = null;
 
   readonly garbageCollector: LruGarbageCollector;
 

packages/firestore/src/local/lru_garbage_collector.ts

@@ -217,7 +217,7 @@ const REGULAR_GC_DELAY_MS = 5 * 60 * 1000;
  * whether or not GC is enabled, as well as which delay to use before the next run.
  */
 export class LruScheduler {
-  private hasRun: boolean;
+  private hasRun: boolean = false;
   private gcTask: CancelablePromise<void> | null;
 
   constructor(

packages/firestore/src/local/memory_persistence.ts

@@ -207,8 +207,9 @@ export class MemoryTransaction implements PersistenceTransaction {
 }
 
 export class MemoryEagerDelegate implements ReferenceDelegate {
-  private inMemoryPins: ReferenceSet | null;
-  private orphanedDocuments: Set<DocumentKey>;
+  private inMemoryPins: ReferenceSet | null = null;
+  // Will be set by onTransactionStarted().
+  private orphanedDocuments!: Set<DocumentKey>;
 
   constructor(private readonly persistence: MemoryPersistence) {}
 
@@ -308,7 +309,7 @@ export class MemoryEagerDelegate implements ReferenceDelegate {
 }
 
 export class MemoryLruDelegate implements ReferenceDelegate, LruDelegate {
-  private inMemoryPins: ReferenceSet | null;
+  private inMemoryPins: ReferenceSet | null = null;
   private orphanedSequenceNumbers: ObjectMap<
     DocumentKey,
     ListenSequenceNumber

packages/firestore/src/local/persistence.ts

@@ -36,7 +36,8 @@ import { ClientId } from './shared_client_state';
  * on persistence.
  */
 export abstract class PersistenceTransaction {
-  readonly currentSequenceNumber: ListenSequenceNumber;
+  // Classes that extend/implement this class always assign this in the constructor.
+  readonly currentSequenceNumber!: ListenSequenceNumber;
 }
 
 /**

packages/firestore/src/local/persistence_promise.ts

@@ -231,7 +231,7 @@ export class PersistencePromise<T> {
   ): PersistencePromise<void> {
     const promises: Array<PersistencePromise<void>> = [];
     collection.forEach((r, s) => {
-      promises.push(f.call(this, r, s));
+      promises.push(f.call(this, r, s as S));
     });
     return this.waitFor(promises);
   }

packages/firestore/src/model/field_value.ts

@@ -119,7 +119,7 @@ export type FieldType = null | boolean | number | string | {};
  * A field value represents a datatype as stored by Firestore.
  */
 export abstract class FieldValue {
-  readonly typeOrder: TypeOrder;
+  readonly typeOrder?: TypeOrder;
 
   abstract value(options?: FieldValueOptions): FieldType;
   abstract isEqual(other: FieldValue): boolean;

packages/firestore/src/model/mutation.ts

@@ -259,9 +259,10 @@ export class Precondition {
  * to some source document.
  */
 export abstract class Mutation {
-  readonly type: MutationType;
-  readonly key: DocumentKey;
-  readonly precondition: Precondition;
+  readonly type?: MutationType;
+  // All classes extending this class assign key in the constructor.
+  readonly key!: DocumentKey;
+  readonly precondition?: Precondition;
 
   /**
    * Applies this mutation to the given MaybeDocument or null for the purposes

packages/firestore/src/model/path.ts

@@ -24,9 +24,10 @@ export const DOCUMENT_KEY_NAME = '__name__';
  * Path represents an ordered sequence of string segments.
  */
 abstract class Path {
-  private segments: string[];
-  private offset: number;
-  private len: number;
+  // These are definitely set in init().
+  private segments!: string[];
+  private offset!: number;
+  private len!: number;
 
   constructor(segments: string[], offset?: number, length?: number) {
     this.init(segments, offset, length);

packages/firestore/src/remote/backoff.ts

@@ -30,7 +30,7 @@ const LOG_TAG = 'ExponentialBackoff';
  * delays causing spikes of load to the backend.
  */
 export class ExponentialBackoff {
-  private currentBaseMs: number;
+  private currentBaseMs: number = 0;
   private timerPromise: CancelablePromise<void> | null = null;
   /** The last backoff attempt, as epoch milliseconds. */
   private lastAttemptTime = Date.now();

packages/firestore/src/remote/persistent_stream.ts

@@ -676,8 +676,10 @@ export class PersistentWriteStream extends PersistentStream<
    *
    * PersistentWriteStream manages propagating this value from responses to the
    * next request.
+   *
+   * This is never null checked but it is zero-length-checked.
    */
-  lastStreamToken: ProtoByteString;
+  lastStreamToken: ProtoByteString = '';
 
   /**
    * Tracks whether or not a handshake has been successfully exchanged and

packages/firestore/src/remote/remote_store.ts

@@ -169,7 +169,8 @@ export class RemoteStore implements TargetMetadataProvider {
   }
 
   /** SyncEngine to notify of watch and write events. */
-  syncEngine: RemoteSyncer;
+  // Will be initialized during FirestoreClient initialization.
+  syncEngine!: RemoteSyncer;
 
   /**
    * Starts up the remote store, creating streams, restoring state from

packages/firestore/src/remote/stream_bridge.ts

@@ -26,9 +26,9 @@ import { Stream } from './connection';
  * interface. The stream callbacks are invoked with the callOn... methods.
  */
 export class StreamBridge<I, O> implements Stream<I, O> {
-  private wrappedOnOpen: () => void | undefined;
-  private wrappedOnClose: (err?: FirestoreError) => void | undefined;
-  private wrappedOnMessage: (msg: O) => void | undefined;
+  private wrappedOnOpen?: () => void | undefined;
+  private wrappedOnClose?: (err?: FirestoreError) => void | undefined;
+  private wrappedOnMessage?: (msg: O) => void | undefined;
 
   private sendFn: (msg: I) => void;
   private closeFn: () => void;

packages/firestore/src/util/async_queue.ts

@@ -193,7 +193,7 @@ export class AsyncQueue {
   private delayedOperations: Array<DelayedOperation<unknown>> = [];
 
   // visible for testing
-  failure: Error;
+  failure?: Error;
 
   // Flag set while there's an outstanding AsyncQueue operation, used for
   // assertion sanity-checks.
@@ -279,7 +279,7 @@ export class AsyncQueue {
     );
     this.delayedOperations.push(delayedOp);
 
-    return delayedOp;
+    return delayedOp as DelayedOperation<T>;
   }
 
   private verifyNotFailed(): void {

packages/firestore/src/util/promise.ts

@@ -29,8 +29,10 @@ export interface CancelablePromise<T> extends Promise<T> {
 
 export class Deferred<R> {
   promise: Promise<R>;
-  resolve: Resolver<R>;
-  reject: Rejecter;
+  // These are assigned in the constructor, but Typescript does not recognize
+  // it because it is async.
+  resolve!: Resolver<R>;
+  reject!: Rejecter;
 
   constructor() {
     this.promise = new Promise((resolve: Resolver<R>, reject: Rejecter) => {

packages/firestore/src/util/sorted_map.ts

@@ -526,11 +526,15 @@ export class LLRBNode<K, V> {
 
 // Represents an empty node (a leaf node in the Red-Black Tree).
 export class LLRBEmptyNode<K, V> {
-  key: K;
-  value: V;
-  color: boolean;
-  left: LLRBNode<K, V>;
-  right: LLRBNode<K, V>;
+  // These values actually can be and are undefined but the isEmpty() check
+  // in each SortedMap function will bail out before they are called.
+  // Typing them as possibly null or undefined causes many errors because
+  // we do not null check every property.
+  key!: K;
+  value!: V;
+  color!: boolean;
+  left!: LLRBNode<K, V>;
+  right!: LLRBNode<K, V>;
   size = 0;
 
   // Returns a copy of the current node.

packages/firestore/test/integration/bootstrap.ts

@@ -29,5 +29,5 @@ import '../../index';
 const testsContext = (require as any).context('.', true, /.test$/);
 const browserTests = testsContext
   .keys()
-  .filter(file => file.indexOf('/node/') < 0);
+  .filter((file: string) => file.indexOf('/node/') < 0);
 browserTests.forEach(testsContext);

packages/firestore/test/integration/browser/webchannel.test.ts

@@ -42,7 +42,7 @@ describeFn('WebChannel', () => {
     const makeUrl = conn.makeUrl.bind(conn);
 
     it('includes project ID and database ID', () => {
-      const url = makeUrl('Commit', {});
+      const url = makeUrl('Commit');
       expect(url).to.equal(
         'http://example.com/v1/projects/testproject/' +
           'databases/(default)/documents:commit'

packages/firestore/test/integration/util/events_accumulator.ts

@@ -27,7 +27,7 @@ export class EventsAccumulator<
   T extends firestore.DocumentSnapshot | firestore.QuerySnapshot
 > {
   private events: T[] = [];
-  private waitingFor: number;
+  private waitingFor: number = 0;
   private deferred: Deferred<T[]> | null = null;
   private rejectAdditionalEvents = false;
 

packages/firestore/test/integration/util/helpers.ts

@@ -93,7 +93,9 @@ export function isRunningAgainstEmulator(): boolean {
  * persistence both disabled and enabled (if the browser is supported).
  */
 export const apiDescribe = apiDescribeInternal.bind(null, describe);
+// @ts-ignore Patching a prototypal function.
 apiDescribe.skip = apiDescribeInternal.bind(null, describe.skip);
+// @ts-ignore Patching a prototypal function.
 apiDescribe.only = apiDescribeInternal.bind(null, describe.only);
 
 function apiDescribeInternal(