From b2fb7af1fab57a82e956c6ad296ac45aa5214923 Mon Sep 17 00:00:00 2001
From: ZHAO Jinxiang <xiaoxiangmoe@gmail.com>
Date: Mon, 6 Sep 2021 16:35:07 +0800
Subject: [PATCH] feat: allow custom compareMethod

---
 src/compute-lines.ts | 6 +++---
 src/index.tsx        | 5 +++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/compute-lines.ts b/src/compute-lines.ts
index 53eb93ca..08e8df07 100644
--- a/src/compute-lines.ts
+++ b/src/compute-lines.ts
@@ -90,9 +90,9 @@ const constructLines = (value: string): string[] => {
 const computeDiff = (
 	oldValue: string,
 	newValue: string,
-	compareMethod: string = DiffMethod.CHARS,
+	compareMethod: string | ((oldStr: string, newStr: string) => diff.Change[]) = DiffMethod.CHARS,
 ): ComputedDiffInformation => {
-	const diffArray: JsDiffChangeObject[] = jsDiff[compareMethod](
+	const diffArray: JsDiffChangeObject[] = ((typeof compareMethod === 'string') ? jsDiff[compareMethod] : compareMethod)(
 		oldValue,
 		newValue,
 	);
@@ -143,7 +143,7 @@ const computeLineInformation = (
 	oldString: string,
 	newString: string,
 	disableWordDiff: boolean = false,
-	compareMethod: string = DiffMethod.CHARS,
+	compareMethod: string | ((oldStr: string, newStr: string) => diff.Change[]) = DiffMethod.CHARS,
 	linesOffset: number = 0,
 ): ComputedLineInformation => {
 	const diffArray = diff.diffLines(
diff --git a/src/index.tsx b/src/index.tsx
index 3e012109..5e7ec169 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -1,6 +1,7 @@
 import * as React from 'react';
 import * as PropTypes from 'prop-types';
 import cn from 'classnames';
+import { Change } from 'diff';
 
 import {
 	computeLineInformation,
@@ -36,7 +37,7 @@ export interface ReactDiffViewerProps {
 	// Enable/Disable word diff.
 	disableWordDiff?: boolean;
 	// JsDiff text diff method from https://github.com/kpdecker/jsdiff/tree/v4.0.1#api
-	compareMethod?: DiffMethod;
+	compareMethod?: DiffMethod | ((oldStr: string, newStr: string) => Change[]);
 	// Number of unmodified lines surrounding each line diff.
 	extraLinesSurroundingDiff?: number;
 	// Show/hide line number.
@@ -99,7 +100,7 @@ class DiffViewer extends React.Component<
 		newValue: PropTypes.string.isRequired,
 		splitView: PropTypes.bool,
 		disableWordDiff: PropTypes.bool,
-		compareMethod: PropTypes.oneOf(Object.values(DiffMethod)),
+		compareMethod: PropTypes.oneOfType([PropTypes.oneOf(Object.values(DiffMethod)), PropTypes.func]),
 		renderContent: PropTypes.func,
 		onLineNumberClick: PropTypes.func,
 		extraLinesSurroundingDiff: PropTypes.number,