Use js-diff instead of diff-match-patch for word level diffs

nix/package.nix

@@ -10,7 +10,7 @@ let
   web = buildNpmPackage {
     name = "web-app";
     src = ../web-app;
-    npmDepsHash = "sha256-J58LwSEQa0p6J6h/wPhpGY/60n9a7TOV5WfNm4K1NH0=";
+    npmDepsHash = "sha256-ab7MJ5vl6XNaAHTyzRxj/Zpk1nEKQLzGmPGJdDrdemg=";
     npmFlags = [ "--legacy-peer-deps" ];
     installPhase = ''
       mkdir -p $out/web-app

web-app/package-lock.json

@@ -8,7 +8,7 @@
       "name": "web-app",
       "version": "0.0.1",
       "dependencies": {
-        "diff-match-patch": "1.0.5",
+        "diff": "7.0.0",
         "highlight.js": "11.11.1",
         "isomorphic-dompurify": "2.22.0",
         "marked": "15.0.7",
@@ -20,7 +20,7 @@
         "@sveltejs/adapter-node": "5.2.12",
         "@sveltejs/kit": "2.20.2",
         "@sveltejs/vite-plugin-svelte": "5.0.3",
-        "@types/diff-match-patch": "1.0.36",
+        "@types/diff": "7.0.2",
         "@types/eslint": "9.6.1",
         "@types/eslint__js": "9.14.0",
         "@types/eslint-config-prettier": "6.11.3",
@@ -1425,10 +1425,10 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/@types/diff-match-patch": {
-      "version": "1.0.36",
-      "resolved": "https://registry.npmjs.org/@types/diff-match-patch/-/diff-match-patch-1.0.36.tgz",
-      "integrity": "sha512-xFdR6tkm0MWvBfO8xXCSsinYxHcqkQUlcHeSpMC2ukzOb6lwQAfDmW+Qt0AvlGd8HpsS28qKsB+oPeJn9I39jg==",
+    "node_modules/@types/diff": {
+      "version": "7.0.2",
+      "resolved": "https://registry.npmjs.org/@types/diff/-/diff-7.0.2.tgz",
+      "integrity": "sha512-JSWRMozjFKsGlEjiiKajUjIJVKuKdE3oVy2DNtK+fUo8q82nhFZ2CPQwicAIkXrofahDXrWJ7mjelvZphMS98Q==",
       "dev": true,
       "license": "MIT"
     },
@@ -2125,11 +2125,14 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/diff-match-patch": {
-      "version": "1.0.5",
-      "resolved": "https://registry.npmjs.org/diff-match-patch/-/diff-match-patch-1.0.5.tgz",
-      "integrity": "sha512-IayShXAgj/QMXgB0IWmKx+rOPuGMhqm5w6jvFxmVenXKIzRqTAAsbBPT3kWQeGANj3jGgvcvv4yK6SxqYmikgw==",
-      "license": "Apache-2.0"
+    "node_modules/diff": {
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/diff/-/diff-7.0.0.tgz",
+      "integrity": "sha512-PJWHUb1RFevKCwaFA9RlG5tCd+FO5iRh9A8HEtkmBH2Li03iJriB6m6JIN4rGz3K3JLawI7/veA1xzRKP6ISBw==",
+      "license": "BSD-3-Clause",
+      "engines": {
+        "node": ">=0.3.1"
+      }
     },
     "node_modules/dompurify": {
       "version": "3.2.4",

web-app/package.json

@@ -19,7 +19,7 @@
     "@sveltejs/adapter-node": "5.2.12",
     "@sveltejs/kit": "2.20.2",
     "@sveltejs/vite-plugin-svelte": "5.0.3",
-    "@types/diff-match-patch": "1.0.36",
+    "@types/diff": "7.0.2",
     "@types/eslint": "9.6.1",
     "@types/eslint__js": "9.14.0",
     "@types/eslint-config-prettier": "6.11.3",
@@ -38,7 +38,7 @@
     "vite": "6.2.5"
   },
   "dependencies": {
-    "diff-match-patch": "1.0.5",
+    "diff": "7.0.0",
     "highlight.js": "11.11.1",
     "isomorphic-dompurify": "2.22.0",
     "marked": "15.0.7",

web-app/src/routes/(authenticated)/website/[websiteId]/logs/+page.server.ts

@@ -3,6 +3,7 @@ import { API_BASE_PREFIX, apiRequest } from "$lib/server/utils";
 import type { ChangeLog, User, Collab } from "$lib/db-schema";
 import DiffMatchPatch from "diff-match-patch";
 import { PAGINATION_MAX_ITEMS } from "$lib/utils";
+import * as Diff from "diff";
 
 export const load: PageServerLoad = async ({ parent, fetch, params, url }) => {
   const userFilter = url.searchParams.get("user");
@@ -76,21 +77,18 @@ export const actions: Actions = {
   computeDiff: async ({ request, fetch }) => {
     const data = await request.formData();
 
-    const dmp = new DiffMatchPatch();
-
     const htmlDiff = (oldValue: string, newValue: string) => {
-      const diff = dmp.diff_main(oldValue, newValue);
+      const diff = Diff.diffWordsWithSpace(oldValue, newValue);
 
       return diff
-        .map(([op, text]) => {
-          const escapedText = text.replace(/</g, "&lt;").replace(/>/g, "&gt;");
+        .map((part) => {
+          const escapedText = part.value.replace(/</g, "&lt;").replace(/>/g, "&gt;");
 
-          switch (op) {
-            case 1:
+          if (part.added) {
             return `<ins>${escapedText}</ins>`;
-            case -1:
+          } else if (part.removed) {
             return `<del>${escapedText}</del>`;
-            default:
+          } else {
             return escapedText;
           }
         })
@@ -112,8 +110,12 @@ export const actions: Actions = {
     return {
       logId: data.get("id"),
       currentDiff: htmlDiff(
-        JSON.stringify(log.old_value, null, 2),
+        JSON.stringify(log.old_value, null, 2)
+          .replace(/\\r\\n|\\n|\\r/g, "\n")
+          .replace(/\\\"/g, '"'),
         JSON.stringify(log.new_value, null, 2)
+          .replace(/\\r\\n|\\n|\\r/g, "\n")
+          .replace(/\\\"/g, '"')
       )
     };
   }

web-app/src/routes/(authenticated)/website/[websiteId]/logs/+page.svelte

@@ -141,9 +141,7 @@
                       <button type="submit">Compute diff</button>
                     </form>
                     {#if form?.logId === id && form?.currentDiff}
-                      <pre>{@html form.currentDiff
-                          .replace(/\\\"/g, '"')
-                          .replace(/\\r\\n|\\n|\\r/g, "\n")}</pre>
+                      <pre>{@html form.currentDiff}</pre>
                     {/if}
                   {/if}