From aab06cfe8f961e543292878fc5f444caadda967a Mon Sep 17 00:00:00 2001
From: Petyo Ivanov <underlog@gmail.com>
Date: Tue, 16 Aug 2022 09:49:48 +0300
Subject: [PATCH] fix: correct typing for itemSize

Closes #724
Reverts #688 - the PR was incorrect, and I misled the contributor.
---
 src/components.tsx                | 5 +++--
 src/hooks/useChangedChildSizes.ts | 4 ++--
 src/interfaces.ts                 | 3 +++
 src/sizeSystem.ts                 | 4 +---
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/components.tsx b/src/components.tsx
index b9c74c9db..37590a7e0 100644
--- a/src/components.tsx
+++ b/src/components.tsx
@@ -21,6 +21,7 @@ import {
   GridRootProps,
   FlatIndexLocationWithAlign,
   FlatScrollIntoViewLocation,
+  SizeFunction,
 } from './interfaces'
 import { List } from './List'
 import { Grid } from './Grid'
@@ -121,7 +122,7 @@ export interface VirtuosoProps<D, C> extends ListRootProps {
    *
    * The default implementation reads `el.getBoundingClientRect().height` and `el.getBoundingClientRect().width`.
    */
-  itemSize?: (el: HTMLElement, dimension: 'height' | 'width') => number
+  itemSize?: SizeFunction
 
   /**
    * Can be used to improve performance if the rendered items are of known size.
@@ -349,7 +350,7 @@ export interface TableVirtuosoProps<D, C> extends Omit<VirtuosoProps<D, C>, 'com
    *
    * The default implementation reads `el.getBoundingClientRect().height` and `el.getBoundingClientRect().width`.
    */
-  itemSize?: (el: HTMLElement, dimension: 'height' | 'width') => number
+  itemSize?: SizeFunction
 
   /**
    * Can be used to improve performance if the rendered items are of known size.
diff --git a/src/hooks/useChangedChildSizes.ts b/src/hooks/useChangedChildSizes.ts
index c57ce3309..9afcdd08a 100644
--- a/src/hooks/useChangedChildSizes.ts
+++ b/src/hooks/useChangedChildSizes.ts
@@ -1,7 +1,7 @@
 import { Log, LogLevel } from '../loggerSystem'
-import { SizeFunction, SizeRange } from '../sizeSystem'
+import { SizeRange } from '../sizeSystem'
 import { useSizeWithElRef } from './useSize'
-import { ScrollContainerState } from '../interfaces'
+import { SizeFunction, ScrollContainerState } from '../interfaces'
 export default function useChangedListContentsSizes(
   callback: (ranges: SizeRange[]) => void,
   itemSize: SizeFunction,
diff --git a/src/interfaces.ts b/src/interfaces.ts
index 2f05b7d8c..7b02b30da 100644
--- a/src/interfaces.ts
+++ b/src/interfaces.ts
@@ -327,3 +327,6 @@ export interface ScrollContainerState {
   scrollTop: number
   viewportHeight: number
 }
+
+/** Calculates the height of `el`, which will be the `Item` element in the DOM. */
+export type SizeFunction = (el: HTMLElement, field: 'offsetHeight' | 'offsetWidth') => number
diff --git a/src/sizeSystem.ts b/src/sizeSystem.ts
index d2e805541..5ac63b1a4 100644
--- a/src/sizeSystem.ts
+++ b/src/sizeSystem.ts
@@ -4,6 +4,7 @@ import * as arrayBinarySearch from './utils/binaryArraySearch'
 import { correctItemSize } from './utils/correctItemSize'
 import { loggerSystem, Log, LogLevel } from './loggerSystem'
 import { recalcSystem } from './recalcSystem'
+import { SizeFunction } from './interfaces'
 
 export interface SizeRange {
   startIndex: number
@@ -273,9 +274,6 @@ const SIZE_MAP = {
   offsetWidth: 'width',
 } as const
 
-/** Calculates the height of `el`, which will be the `Item` element in the DOM. */
-export type SizeFunction = (el: HTMLElement, field: 'offsetHeight' | 'offsetWidth') => number
-
 export const sizeSystem = u.system(
   ([{ log }, { recalcInProgress }]) => {
     const sizeRanges = u.stream<SizeRange[]>()