fix: Maximum call stack size exceeded for large diffs

Author: Themezv

src/line-by-line-renderer.ts

@@ -11,6 +11,7 @@ import {
   DiffLineContext,
   DiffLineInserted,
 } from './types';
+import { max } from './utils';
 
 export interface LineByLineRendererConfig extends renderUtils.RenderConfig {
   renderNothingWhenEmpty?: boolean;
@@ -30,27 +31,6 @@ const baseTemplatesPath = 'line-by-line';
 const iconsBaseTemplatesPath = 'icon';
 const tagsBaseTemplatesPath = 'tag';
 
-/**
- * @description Finds the maximum value in an array of numbers safely
- *
- * This function iterates through the array manually instead of using Math.max(...arr)
- * to avoid "Maximum call stack size exceeded" errors that can occur when spreading
- * very large arrays as function arguments. This is especially important when dealing
- * with large diffs that may contain thousands of lines.
- *
- * @param arr - The array of numbers
- * @returns The maximum value in the array
- */
-function max(arr: number[]): number {
-  const length = arr.length;
-  let max = -Infinity;
-
-  for (let i = 0; i < length; i++) {
-    max = Math.max(max, arr[i]);
-  }
-  return max;
-}
-
 export default class LineByLineRenderer {
   private readonly hoganUtils: HoganJsUtils;
   private readonly config: typeof defaultLineByLineRendererConfig;

src/side-by-side-renderer.ts

@@ -11,6 +11,7 @@ import {
   DiffLineInserted,
   DiffLineContent,
 } from './types';
+import { max } from './utils';
 
 export interface SideBySideRendererConfig extends renderUtils.RenderConfig {
   renderNothingWhenEmpty?: boolean;
@@ -194,10 +195,7 @@ export default class SideBySideRenderer {
     matcher: Rematch.MatcherFn<DiffLine>,
   ): DiffLine[][][] {
     const comparisons = oldLines.length * newLines.length;
-    const maxLineSizeInBlock = Math.max.apply(
-      null,
-      [0].concat(oldLines.concat(newLines).map(elem => elem.content.length)),
-    );
+    const maxLineSizeInBlock = max(oldLines.concat(newLines).map(elem => elem.content.length));
     const doMatching =
       comparisons < this.config.matchingMaxComparisons &&
       maxLineSizeInBlock < this.config.maxLineSizeInBlockForComparison &&

src/utils.ts

@@ -52,3 +52,24 @@ export function hashCode(text: string): number {
 
   return hash;
 }
+
+/**
+ * @description Finds the maximum value in an array of numbers safely
+ *
+ * This function iterates through the array manually instead of using Math.max(...arr)
+ * to avoid "Maximum call stack size exceeded" errors that can occur when spreading
+ * very large arrays as function arguments. This is especially important when dealing
+ * with large diffs that may contain thousands of lines.
+ *
+ * @param arr - The array of numbers
+ * @returns The maximum value in the array
+ */
+export function max(arr: number[]): number {
+  const length = arr.length;
+  let max = -Infinity;
+
+  for (let i = 0; i < length; i++) {
+    max = Math.max(max, arr[i]);
+  }
+  return max;
+}