Reduce size impact of Target/TargetImpl pattern

.changeset/tricky-rocks-dream.md

@@ -0,0 +1,2 @@
+---
+---

packages/firestore/src/core/target.ts

@@ -37,31 +37,28 @@ import { debugCast } from '../util/assert';
  * maps to a single WatchTarget in RemoteStore and a single TargetData entry
  * in persistence.
  */
-export class Target {
-  protected constructor(
-    readonly path: ResourcePath,
-    readonly collectionGroup: string | null,
-    readonly orderBy: OrderBy[],
-    readonly filters: Filter[],
-    readonly limit: number | null,
-    readonly startAt: Bound | null,
-    readonly endAt: Bound | null
-  ) {}
+export interface Target {
+  readonly path: ResourcePath;
+  readonly collectionGroup: string | null;
+  readonly orderBy: OrderBy[];
+  readonly filters: Filter[];
+  readonly limit: number | null;
+  readonly startAt: Bound | null;
+  readonly endAt: Bound | null;
 }
 
-class TargetImpl extends Target {
+// Visible for testing
+export class TargetImpl implements Target {
   memoizedCanonicalId: string | null = null;
   constructor(
-    path: ResourcePath,
-    collectionGroup: string | null = null,
-    orderBy: OrderBy[] = [],
-    filters: Filter[] = [],
-    limit: number | null = null,
-    startAt: Bound | null = null,
-    endAt: Bound | null = null
-  ) {
-    super(path, collectionGroup, orderBy, filters, limit, startAt, endAt);
-  }
+    readonly path: ResourcePath,
+    readonly collectionGroup: string | null = null,
+    readonly orderBy: OrderBy[] = [],
+    readonly filters: Filter[] = [],
+    readonly limit: number | null = null,
+    readonly startAt: Bound | null = null,
+    readonly endAt: Bound | null = null
+  ) {}
 }
 
 /**

packages/firestore/test/unit/local/target_cache.test.ts

@@ -34,7 +34,12 @@ import {
 import { Timestamp } from '../../../src/api/timestamp';
 import * as persistenceHelpers from './persistence_test_helpers';
 import { TestTargetCache } from './test_target_cache';
-import { canonifyTarget, Target, targetEquals } from '../../../src/core/target';
+import {
+  canonifyTarget,
+  Target,
+  targetEquals,
+  TargetImpl
+} from '../../../src/core/target';
 
 describe('MemoryTargetCache', () => {
   genericTargetCacheTests(persistenceHelpers.testMemoryEagerPersistence);
@@ -106,7 +111,7 @@ describe('IndexedDbTargetCache', () => {
 function genericTargetCacheTests(
   persistencePromise: () => Promise<Persistence>
 ): void {
-  addEqualityMatcher({ equalsFn: targetEquals, forType: Target });
+  addEqualityMatcher({ equalsFn: targetEquals, forType: TargetImpl });
   let cache: TestTargetCache;
 
   const QUERY_ROOMS = Query.atPath(path('rooms')).toTarget();

packages/firestore/test/unit/specs/describe_spec.ts

@@ -26,7 +26,7 @@ import { SpecBuilder } from './spec_builder';
 import { SpecStep } from './spec_test_runner';
 
 import * as stringify from 'json-stable-stringify';
-import { Target, targetEquals } from '../../../src/core/target';
+import { targetEquals, TargetImpl } from '../../../src/core/target';
 
 // Disables all other tests; useful for debugging. Multiple tests can have
 // this tag and they'll all be run (but all others won't).
@@ -240,7 +240,7 @@ export function describeSpec(
 
   if (!writeJSONFile) {
     describe(name, () => {
-      addEqualityMatcher({ equalsFn: targetEquals, forType: Target });
+      addEqualityMatcher({ equalsFn: targetEquals, forType: TargetImpl });
       return builder();
     });
   } else {