Review

Author: schmidt-sebastian

packages/firestore/src/model/field_index.ts

@@ -33,7 +33,7 @@ const INITIAL_LARGEST_BATCH_ID = -1;
  * The initial sequence number for each index. Gets updated during index
  * backfill.
  */
-const INITIAL_SEQUENCE_NUMBER = 0;
+export const INITIAL_SEQUENCE_NUMBER = 0;
 
 /**
  * An index definition for field indexes in Firestore.
@@ -126,10 +126,15 @@ function indexSegmentComparator(
   return primitiveComparator(left.kind, right.kind);
 }
 
-/** Stores the "high water mark" that indicates how updated the Index is for the current user. */
+/**
+ * Stores the "high water mark" that indicates how updated the Index is for the
+ * current user.
+ */
 export class IndexState {
   constructor(
-    /** Indicates when the index was last updated (relative to other indexes). */
+    /**
+     * Indicates when the index was last updated (relative to other indexes).
+     */
     readonly sequenceNumber: number,
     /** The the latest indexed read time, document and batch id. */
     readonly offset: IndexOffset

packages/firestore/test/util/helpers.ts

@@ -77,7 +77,8 @@ import {
   IndexKind,
   IndexOffset,
   IndexSegment,
-  IndexState
+  IndexState,
+  INITIAL_SEQUENCE_NUMBER
 } from '../../src/model/field_index';
 import { FieldMask } from '../../src/model/field_mask';
 import {
@@ -242,7 +243,7 @@ export function fieldIndex(
     (options.fields ?? []).map(
       entry => new IndexSegment(field(entry[0]), entry[1])
     ),
-    new IndexState(-1, options.offset ?? IndexOffset.min())
+    new IndexState(INITIAL_SEQUENCE_NUMBER, options.offset ?? IndexOffset.min())
   );
 }