feat: add support for dates to max and min functions.

.changeset/brave-rocks-lie.md

@@ -0,0 +1,6 @@
+---
+"@tanstack/db-ivm": patch
+"@tanstack/db": patch
+---
+
+Add support for Date objects to min/max aggregates and range queries when using an index.

packages/db-ivm/src/operators/groupBy.ts

@@ -214,19 +214,21 @@ export function avg<T>(
  * Creates a min aggregate function that computes the minimum value in a group
  * @param valueExtractor Function to extract a numeric value from each data entry
  */
-export function min<T>(
-  valueExtractor: (value: T) => number = (v) => v as unknown as number
-): AggregateFunction<T, number, number> {
+export function min<T, V extends number | Date | bigint>(
+  valueExtractor: (value: T) => V = (v) => v as unknown as V
+): AggregateFunction<T, V, V> {
   return {
     preMap: (data: T) => valueExtractor(data),
-    reduce: (values: Array<[number, number]>) => {
-      let minValue = Number.POSITIVE_INFINITY
+    reduce: (values) => {
+      let minValue: V | undefined
       for (const [value, _multiplicity] of values) {
-        if (value < minValue) {
+        if (minValue && value < minValue) {
+          minValue = value
+        } else if (!minValue) {
           minValue = value
         }
       }
-      return minValue === Number.POSITIVE_INFINITY ? 0 : minValue
+      return minValue ?? (0 as V)
     },
   }
 }
@@ -235,19 +237,21 @@ export function min<T>(
  * Creates a max aggregate function that computes the maximum value in a group
  * @param valueExtractor Function to extract a numeric value from each data entry
  */
-export function max<T>(
-  valueExtractor: (value: T) => number = (v) => v as unknown as number
-): AggregateFunction<T, number, number> {
+export function max<T, V extends number | Date | bigint>(
+  valueExtractor: (value: T) => V = (v) => v as unknown as V
+): AggregateFunction<T, V, V> {
   return {
     preMap: (data: T) => valueExtractor(data),
-    reduce: (values: Array<[number, number]>) => {
-      let maxValue = Number.NEGATIVE_INFINITY
+    reduce: (values) => {
+      let maxValue: V | undefined
       for (const [value, _multiplicity] of values) {
-        if (value > maxValue) {
+        if (maxValue && value > maxValue) {
+          maxValue = value
+        } else if (!maxValue) {
           maxValue = value
         }
       }
-      return maxValue === Number.NEGATIVE_INFINITY ? 0 : maxValue
+      return maxValue ?? (0 as V)
     },
   }
 }

packages/db-ivm/tests/operators/groupBy.test.ts

@@ -524,13 +524,16 @@ describe(`Operators`, () => {
       const input = graph.newInput<{
         category: string
         amount: number
+        date: Date
       }>()
       let latestMessage: any = null
 
       input.pipe(
         groupBy((data) => ({ category: data.category }), {
           minimum: min((data) => data.amount),
           maximum: max((data) => data.amount),
+          min_date: min((data) => data.date),
+          max_date: max((data) => data.date),
         }),
         output((message) => {
           latestMessage = message
@@ -542,11 +545,11 @@ describe(`Operators`, () => {
       // Initial data
       input.sendData(
         new MultiSet([
-          [{ category: `A`, amount: 10 }, 1],
-          [{ category: `A`, amount: 20 }, 1],
-          [{ category: `A`, amount: 5 }, 1],
-          [{ category: `B`, amount: 30 }, 1],
-          [{ category: `B`, amount: 15 }, 1],
+          [{ category: `A`, amount: 10, date: new Date(`2025/12/13`) }, 1],
+          [{ category: `A`, amount: 20, date: new Date(`2025/12/15`) }, 1],
+          [{ category: `A`, amount: 5, date: new Date(`2025/12/12`) }, 1],
+          [{ category: `B`, amount: 30, date: new Date(`2025/12/12`) }, 1],
+          [{ category: `B`, amount: 15, date: new Date(`2025/12/13`) }, 1],
         ])
       )
 
@@ -563,6 +566,8 @@ describe(`Operators`, () => {
               category: `A`,
               minimum: 5,
               maximum: 20,
+              min_date: new Date(`2025/12/12`),
+              max_date: new Date(`2025/12/15`),
             },
           ],
           1,
@@ -574,6 +579,8 @@ describe(`Operators`, () => {
               category: `B`,
               minimum: 15,
               maximum: 30,
+              min_date: new Date(`2025/12/12`),
+              max_date: new Date(`2025/12/13`),
             },
           ],
           1,

packages/db/src/indexes/btree-index.ts

@@ -71,15 +71,18 @@ export class BTreeIndex<
       )
     }
 
+    // Normalize the value for Map key usage
+    const normalizedValue = this.normalizeMapKey(indexedValue)
+
     // Check if this value already exists
-    if (this.valueMap.has(indexedValue)) {
+    if (this.valueMap.has(normalizedValue)) {
       // Add to existing set
-      this.valueMap.get(indexedValue)!.add(key)
+      this.valueMap.get(normalizedValue)!.add(key)
     } else {
       // Create new set for this value
       const keySet = new Set<TKey>([key])
-      this.valueMap.set(indexedValue, keySet)
-      this.orderedEntries.set(indexedValue, undefined)
+      this.valueMap.set(normalizedValue, keySet)
+      this.orderedEntries.set(normalizedValue, undefined)
     }
 
     this.indexedKeys.add(key)
@@ -101,16 +104,19 @@ export class BTreeIndex<
       return
     }
 
-    if (this.valueMap.has(indexedValue)) {
-      const keySet = this.valueMap.get(indexedValue)!
+    // Normalize the value for Map key usage
+    const normalizedValue = this.normalizeMapKey(indexedValue)
+
+    if (this.valueMap.has(normalizedValue)) {
+      const keySet = this.valueMap.get(normalizedValue)!
       keySet.delete(key)
 
       // If set is now empty, remove the entry entirely
       if (keySet.size === 0) {
-        this.valueMap.delete(indexedValue)
+        this.valueMap.delete(normalizedValue)
 
         // Remove from ordered entries
-        this.orderedEntries.delete(indexedValue)
+        this.orderedEntries.delete(normalizedValue)
       }
     }
 
@@ -195,7 +201,8 @@ export class BTreeIndex<
    * Performs an equality lookup
    */
   equalityLookup(value: any): Set<TKey> {
-    return new Set(this.valueMap.get(value) ?? [])
+    const normalizedValue = this.normalizeMapKey(value)
+    return new Set(this.valueMap.get(normalizedValue) ?? [])
   }
 
   /**
@@ -206,8 +213,10 @@ export class BTreeIndex<
     const { from, to, fromInclusive = true, toInclusive = true } = options
     const result = new Set<TKey>()
 
-    const fromKey = from ?? this.orderedEntries.minKey()
-    const toKey = to ?? this.orderedEntries.maxKey()
+    const normalizedFrom = this.normalizeMapKey(from)
+    const normalizedTo = this.normalizeMapKey(to)
+    const fromKey = normalizedFrom ?? this.orderedEntries.minKey()
+    const toKey = normalizedTo ?? this.orderedEntries.maxKey()
 
     this.orderedEntries.forRange(
       fromKey,
@@ -240,7 +249,7 @@ export class BTreeIndex<
     const keysInResult: Set<TKey> = new Set()
     const result: Array<TKey> = []
     const nextKey = (k?: any) => this.orderedEntries.nextHigherKey(k)
-    let key = from
+    let key = this.normalizeMapKey(from)
 
     while ((key = nextKey(key)) && result.length < n) {
       const keys = this.valueMap.get(key)
@@ -266,7 +275,8 @@ export class BTreeIndex<
     const result = new Set<TKey>()
 
     for (const value of values) {
-      const keys = this.valueMap.get(value)
+      const normalizedValue = this.normalizeMapKey(value)
+      const keys = this.valueMap.get(normalizedValue)
       if (keys) {
         keys.forEach((key) => result.add(key))
       }
@@ -289,4 +299,15 @@ export class BTreeIndex<
   get valueMapData(): Map<any, Set<TKey>> {
     return this.valueMap
   }
+
+  /**
+   * Normalizes values for use as Map keys to ensure proper equality and range queries
+   * For Date objects, uses timestamp.
+   */
+  private normalizeMapKey(value: any): any {
+    if (value instanceof Date) {
+      return value.valueOf()
+    }
+    return value
+  }
 }

packages/db/src/query/builder/functions.ts

@@ -53,10 +53,10 @@ type ExtractType<T> =
 // Helper type to determine aggregate return type based on input nullability
 type AggregateReturnType<T> =
   ExtractType<T> extends infer U
-    ? U extends number | undefined | null
+    ? U extends number | undefined | null | Date | bigint
       ? Aggregate<U>
-      : Aggregate<number | undefined | null>
-    : Aggregate<number | undefined | null>
+      : Aggregate<number | undefined | null | Date | bigint>
+    : Aggregate<number | undefined | null | Date | bigint>
 
 // Helper type to determine string function return type based on input nullability
 type StringFunctionReturnType<T> =

packages/db/src/query/compiler/evaluators.ts

@@ -144,6 +144,9 @@ function compileFunction(func: Func, isSingleRow: boolean): (data: any) => any {
       return (data) => {
         const a = argA(data)
         const b = argB(data)
+        if (a instanceof Date && b instanceof Date) {
+          return a.valueOf() == b.valueOf()
+        }
         return a === b
       }
     }

packages/db/src/query/compiler/group-by.ts

@@ -349,6 +349,20 @@ function getAggregateFunction(aggExpr: Aggregate) {
     return typeof value === `number` ? value : value != null ? Number(value) : 0
   }
 
+  // Create a value extractor function for the expression to aggregate
+  const valueExtractorWithDate = ([, namespacedRow]: [
+    string,
+    NamespacedRow,
+  ]) => {
+    const value = compiledExpr(namespacedRow)
+    // Ensure we return a number for numeric aggregate functions
+    return typeof value === `number` || value instanceof Date
+      ? value
+      : value != null
+        ? Number(value)
+        : 0
+  }
+
   // Create a raw value extractor function for the expression to aggregate
   const rawValueExtractor = ([, namespacedRow]: [string, NamespacedRow]) => {
     return compiledExpr(namespacedRow)
@@ -363,9 +377,9 @@ function getAggregateFunction(aggExpr: Aggregate) {
     case `avg`:
       return avg(valueExtractor)
     case `min`:
-      return min(valueExtractor)
+      return min(valueExtractorWithDate)
     case `max`:
-      return max(valueExtractor)
+      return max(valueExtractorWithDate)
     default:
       throw new UnsupportedAggregateFunctionError(aggExpr.name)
   }

packages/db/src/utils/comparison.ts

@@ -51,7 +51,7 @@ export const ascComparator = (a: any, b: any, opts: CompareOptions): number => {
 
   // If both are dates, compare them
   if (a instanceof Date && b instanceof Date) {
-    return a.getTime() - b.getTime()
+    return a.valueOf() - b.valueOf()
   }
 
   // If at least one of the values is an object, use stable IDs for comparison

packages/db/tests/query/group-by.test-d.ts

@@ -23,6 +23,7 @@ type Order = {
   amount: number
   status: string
   date: string
+  date_instance: Date
   product_category: string
   quantity: number
   discount: number
@@ -37,6 +38,7 @@ const sampleOrders: Array<Order> = [
     amount: 100,
     status: `completed`,
     date: `2023-01-01`,
+    date_instance: new Date(`2023-01-01`),
     product_category: `electronics`,
     quantity: 2,
     discount: 0,
@@ -48,6 +50,7 @@ const sampleOrders: Array<Order> = [
     amount: 200,
     status: `completed`,
     date: `2023-01-15`,
+    date_instance: new Date(`2023-01-15`),
     product_category: `electronics`,
     quantity: 1,
     discount: 10,
@@ -81,6 +84,8 @@ describe(`Query GROUP BY Types`, () => {
             avg_amount: avg(orders.amount),
             min_amount: min(orders.amount),
             max_amount: max(orders.amount),
+            min_date: min(orders.date_instance),
+            max_date: max(orders.date_instance),
           })),
     })
 
@@ -93,6 +98,8 @@ describe(`Query GROUP BY Types`, () => {
           avg_amount: number
           min_amount: number
           max_amount: number
+          min_date: Date
+          max_date: Date
         }
       | undefined
     >()