refactor: create and export function handler types

src/v1/providers/analytics.ts

@@ -30,6 +30,9 @@ export const provider = "google.analytics";
 /** @internal */
 export const service = "app-measurement.com";
 
+/** Handler used by {@link AnalyticsEventBuilder.onLog}. */
+export type OnLogHandler = (event: AnalyticsEvent, context: EventContext) => PromiseLike<any> | any;
+
 /**
  * Registers a function to handle analytics events.
  *
@@ -75,9 +78,7 @@ export class AnalyticsEventBuilder {
    *
    * @returns A function that you can export and deploy.
    */
-  onLog(
-    handler: (event: AnalyticsEvent, context: EventContext) => PromiseLike<any> | any
-  ): CloudFunction<AnalyticsEvent> {
+  onLog(handler: OnLogHandler): CloudFunction<AnalyticsEvent> {
     const dataConstructor = (raw: LegacyEvent) => {
       return new AnalyticsEvent(raw.data);
     };

src/v1/providers/auth.ts

@@ -55,6 +55,32 @@ export type { UserRecord, UserInfo };
 
 export { HttpsError };
 
+/** Handler used by {@link UserBuilder.onCreate}. */
+export type OnCreateHandler = (user: UserRecord, context: EventContext) => PromiseLike<any> | any;
+
+/** Handler used by {@link UserBuilder.onDelete}. */
+export type OnDeleteHandler = OnCreateHandler;
+
+/** Handler used by {@link UserBuilder.beforeCreate}. */
+export type BeforeCreateHandler = (
+  user: AuthUserRecord,
+  context: AuthEventContext
+) => MaybeAsync<BeforeCreateResponse | void>;
+
+/** Handler used by {@link UserBuilder.beforeSignIn}. */
+export type BeforeSignInHandler = (
+  user: AuthUserRecord,
+  context: AuthEventContext
+) => MaybeAsync<BeforeSignInResponse | void>;
+
+/** Handler used by {@link UserBuilder.beforeEmail}. */
+export type BeforeEmailHandler = (
+  context: AuthEventContext
+) => MaybeAsync<BeforeEmailResponse | void>;
+
+/** Handler used by {@link UserBuilder.beforeSms}. */
+export type BeforeSmsHandler = (context: AuthEventContext) => MaybeAsync<BeforeSmsResponse | void>;
+
 /** @internal */
 export const provider = "google.firebase.auth";
 /** @internal */
@@ -126,9 +152,7 @@ export class UserBuilder {
    *
    * @public
    */
-  onCreate(
-    handler: (user: UserRecord, context: EventContext) => PromiseLike<any> | any
-  ): CloudFunction<UserRecord> {
+  onCreate(handler: OnCreateHandler): CloudFunction<UserRecord> {
     return this.onOperation(handler, "user.create");
   }
 
@@ -139,9 +163,7 @@ export class UserBuilder {
    *
    * @public
    */
-  onDelete(
-    handler: (user: UserRecord, context: EventContext) => PromiseLike<any> | any
-  ): CloudFunction<UserRecord> {
+  onDelete(handler: OnDeleteHandler): CloudFunction<UserRecord> {
     return this.onOperation(handler, "user.delete");
   }
 
@@ -152,12 +174,7 @@ export class UserBuilder {
    *
    * @public
    */
-  beforeCreate(
-    handler: (
-      user: AuthUserRecord,
-      context: AuthEventContext
-    ) => MaybeAsync<BeforeCreateResponse | void>
-  ): BlockingFunction {
+  beforeCreate(handler: BeforeCreateHandler): BlockingFunction {
     return this.beforeOperation(handler, "beforeCreate");
   }
 
@@ -168,24 +185,15 @@ export class UserBuilder {
    *
    * @public
    */
-  beforeSignIn(
-    handler: (
-      user: AuthUserRecord,
-      context: AuthEventContext
-    ) => MaybeAsync<BeforeSignInResponse | void>
-  ): BlockingFunction {
+  beforeSignIn(handler: BeforeSignInHandler): BlockingFunction {
     return this.beforeOperation(handler, "beforeSignIn");
   }
 
-  beforeEmail(
-    handler: (context: AuthEventContext) => MaybeAsync<BeforeEmailResponse | void>
-  ): BlockingFunction {
+  beforeEmail(handler: BeforeEmailHandler): BlockingFunction {
     return this.beforeOperation(handler, "beforeSendEmail");
   }
 
-  beforeSms(
-    handler: (context: AuthEventContext) => MaybeAsync<BeforeSmsResponse | void>
-  ): BlockingFunction {
+  beforeSms(handler: BeforeSmsHandler): BlockingFunction {
     return this.beforeOperation(handler, "beforeSendSms");
   }
 

src/v1/providers/database.ts

@@ -34,6 +34,24 @@ import { expr } from "../../params";
 
 export { DataSnapshot };
 
+/** Handler used by {@link RefBuilder.onWrite}. */
+export type OnWriteHandler<Ref extends string = string> = (
+  change: Change<DataSnapshot>,
+  context: EventContext<ParamsOf<Ref>>
+) => PromiseLike<any> | any;
+
+/** Handler used by {@link RefBuilder.onUpdate}. */
+export type OnUpdateHandler<Ref extends string = string> = OnWriteHandler<Ref>;
+
+/** Handler used by {@link RefBuilder.onCreate}. */
+export type OnCreateHandler<Ref extends string = string> = (
+  snapshot: DataSnapshot,
+  context: EventContext<ParamsOf<Ref>>
+) => PromiseLike<any> | any;
+
+/** Handler used by {@link RefBuilder.onDelete}. */
+export type OnDeleteHandler<Ref extends string = string> = OnCreateHandler<Ref>;
+
 /** @internal */
 export const provider = "google.firebase.database";
 /** @internal */
@@ -182,12 +200,7 @@ export class RefBuilder<Ref extends string> {
    *   write occurs.
    * @returns A function that you can export and deploy.
    */
-  onWrite(
-    handler: (
-      change: Change<DataSnapshot>,
-      context: EventContext<ParamsOf<Ref>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<Change<DataSnapshot>> {
+  onWrite(handler: OnWriteHandler<Ref>): CloudFunction<Change<DataSnapshot>> {
     return this.onOperation(handler, "ref.write", this.changeConstructor);
   }
 
@@ -199,12 +212,7 @@ export class RefBuilder<Ref extends string> {
    *   write occurs.
    * @returns A function which you can export and deploy.
    */
-  onUpdate(
-    handler: (
-      change: Change<DataSnapshot>,
-      context: EventContext<ParamsOf<Ref>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<Change<DataSnapshot>> {
+  onUpdate(handler: OnUpdateHandler<Ref>): CloudFunction<Change<DataSnapshot>> {
     return this.onOperation(handler, "ref.update", this.changeConstructor);
   }
 
@@ -216,12 +224,7 @@ export class RefBuilder<Ref extends string> {
    *   Firebase Realtime Database.
    * @returns A function that you can export and deploy.
    */
-  onCreate(
-    handler: (
-      snapshot: DataSnapshot,
-      context: EventContext<ParamsOf<Ref>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<DataSnapshot> {
+  onCreate(handler: OnCreateHandler<Ref>): CloudFunction<DataSnapshot> {
     const dataConstructor = (raw: LegacyEvent) => {
       const [dbInstance, path] = extractInstanceAndPath(
         raw.context.resource.name,
@@ -240,12 +243,7 @@ export class RefBuilder<Ref extends string> {
    *   Firebase Realtime Database.
    * @returns A function that you can export and deploy.
    */
-  onDelete(
-    handler: (
-      snapshot: DataSnapshot,
-      context: EventContext<ParamsOf<Ref>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<DataSnapshot> {
+  onDelete(handler: OnDeleteHandler<Ref>): CloudFunction<DataSnapshot> {
     const dataConstructor = (raw: LegacyEvent) => {
       const [dbInstance, path] = extractInstanceAndPath(
         raw.context.resource.name,

src/v1/providers/firestore.ts

@@ -44,6 +44,27 @@ export const defaultDatabase = "(default)";
 export type DocumentSnapshot = firestore.DocumentSnapshot;
 export type QueryDocumentSnapshot = firestore.QueryDocumentSnapshot;
 
+/** Handler used by {@link DocumentBuilder.onWrite}. */
+export type OnWriteHandler<Path extends string = string> = (
+  change: Change<DocumentSnapshot>,
+  context: EventContext<ParamsOf<Path>>
+) => PromiseLike<any> | any;
+
+/** Handler used by {@link DocumentBuilder.onUpdate}. */
+export type OnUpdateHandler<Path extends string = string> = (
+  change: Change<QueryDocumentSnapshot>,
+  context: EventContext<ParamsOf<Path>>
+) => PromiseLike<any> | any;
+
+/** Handler used by {@link DocumentBuilder.onCreate}. */
+export type OnCreateHandler<Path extends string = string> = (
+  snapshot: QueryDocumentSnapshot,
+  context: EventContext<ParamsOf<Path>>
+) => PromiseLike<any> | any;
+
+/** Handler used by {@link DocumentBuilder.onDelete}. */
+export type OnDeleteHandler<Path extends string = string> = OnCreateHandler<Path>;
+
 /**
  * Select the Firestore document to listen to for events.
  * @param path Full database path to listen to. This includes the name of
@@ -166,42 +187,22 @@ export class DocumentBuilder<Path extends string> {
   }
 
   /** Respond to all document writes (creates, updates, or deletes). */
-  onWrite(
-    handler: (
-      change: Change<DocumentSnapshot>,
-      context: EventContext<ParamsOf<Path>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<Change<DocumentSnapshot>> {
+  onWrite(handler: OnWriteHandler<Path>): CloudFunction<Change<DocumentSnapshot>> {
     return this.onOperation(handler, "document.write", changeConstructor);
   }
 
   /** Respond only to document updates. */
-  onUpdate(
-    handler: (
-      change: Change<QueryDocumentSnapshot>,
-      context: EventContext<ParamsOf<Path>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<Change<QueryDocumentSnapshot>> {
+  onUpdate(handler: OnUpdateHandler<Path>): CloudFunction<Change<QueryDocumentSnapshot>> {
     return this.onOperation(handler, "document.update", changeConstructor);
   }
 
   /** Respond only to document creations. */
-  onCreate(
-    handler: (
-      snapshot: QueryDocumentSnapshot,
-      context: EventContext<ParamsOf<Path>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<QueryDocumentSnapshot> {
+  onCreate(handler: OnCreateHandler<Path>): CloudFunction<QueryDocumentSnapshot> {
     return this.onOperation(handler, "document.create", snapshotConstructor);
   }
 
   /** Respond only to document deletions. */
-  onDelete(
-    handler: (
-      snapshot: QueryDocumentSnapshot,
-      context: EventContext<ParamsOf<Path>>
-    ) => PromiseLike<any> | any
-  ): CloudFunction<QueryDocumentSnapshot> {
+  onDelete(handler: OnDeleteHandler<Path>): CloudFunction<QueryDocumentSnapshot> {
     return this.onOperation(handler, "document.delete", beforeSnapshotConstructor);
   }
 

src/v1/providers/https.ts

@@ -20,7 +20,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-import * as express from "express";
+import type * as express from "express";
 
 import { convertIfPresent, convertInvoker } from "../../common/encoding";
 import {
@@ -40,30 +40,32 @@ import { wrapTraceContext } from "../../v2/trace";
 export { HttpsError };
 export type { Request, CallableContext, FunctionsErrorCode };
 
+/** Handler used by {@link onRequest}. */
+export type OnRequestHandler = (req: Request, resp: express.Response) => void | Promise<void>;
+
+/** Handler used by {@link onCall}. */
+export type OnCallHandler = (data: any, context: CallableContext) => any | Promise<any>;
+
 /**
  * Handle HTTP requests.
  * @param handler A function that takes a request and response object,
  * same signature as an Express app.
  */
-export function onRequest(
-  handler: (req: Request, resp: express.Response) => void | Promise<void>
-): HttpsFunction {
+export function onRequest(handler: OnRequestHandler): HttpsFunction {
   return _onRequestWithOptions(handler, {});
 }
 
 /**
  * Declares a callable method for clients to call using a Firebase SDK.
  * @param handler A method that takes a data and context and returns a value.
  */
-export function onCall(
-  handler: (data: any, context: CallableContext) => any | Promise<any>
-): HttpsFunction & Runnable<any> {
+export function onCall(handler: OnCallHandler): HttpsFunction & Runnable<any> {
   return _onCallWithOptions(handler, {});
 }
 
 /** @internal */
 export function _onRequestWithOptions(
-  handler: (req: Request, resp: express.Response) => void | Promise<void>,
+  handler: OnRequestHandler,
   options: DeploymentOptions
 ): HttpsFunction {
   // lets us add __endpoint without altering handler:
@@ -101,7 +103,7 @@ export function _onRequestWithOptions(
 
 /** @internal */
 export function _onCallWithOptions(
-  handler: (data: any, context: CallableContext) => any | Promise<any>,
+  handler: OnCallHandler,
   options: DeploymentOptions
 ): HttpsFunction & Runnable<any> {
   // fix the length of handler to make the call to handler consistent

src/v1/providers/pubsub.ts

@@ -30,6 +30,12 @@ export const provider = "google.pubsub";
 /** @internal */
 export const service = "pubsub.googleapis.com";
 
+/** Handler used by {@link TopicBuilder.onPublish}. */
+export type OnPublishHandler = (message: Message, context: EventContext) => PromiseLike<any> | any;
+
+/** Handler used by {@link ScheduleBuilder.onRun}. */
+export type OnRunHandler = (context: EventContext) => PromiseLike<any> | any;
+
 /**
  * Registers a Cloud Function triggered when a Google Cloud Pub/Sub message
  * is sent to a specified topic.
@@ -79,9 +85,7 @@ export class TopicBuilder {
    *   is published.
    * @returns A function that you can export and deploy.
    */
-  onPublish(
-    handler: (message: Message, context: EventContext) => PromiseLike<any> | any
-  ): CloudFunction<Message> {
+  onPublish(handler: OnPublishHandler): CloudFunction<Message> {
     return makeCloudFunction({
       handler,
       provider,
@@ -156,7 +160,7 @@ export class ScheduleBuilder {
    *   scheduler job sends a Pub/Sub message.
    * @returns A function that you can export and deploy.
    */
-  onRun(handler: (context: EventContext) => PromiseLike<any> | any) {
+  onRun(handler: OnRunHandler) {
     const cloudFunction = makeCloudFunction({
       contextOnlyHandler: handler,
       provider,