feat: implement text diff tool

app/text/diff/layout.tsx

@@ -1,10 +1,11 @@
+import { PropsWithChildren } from "react";
 import { Metadata } from "next";
 
 import { toolGroups } from "@/config/tools";
 
 export const metadata: Metadata = {
-  title: toolGroups.text.tools.inspector_and_case_converter.longTitle,
-  description: toolGroups.text.tools.inspector_and_case_converter.description,
+  title: toolGroups.text.tools.diff.longTitle,
+  description: toolGroups.text.tools.diff.description,
   robots: {
     googleBot: {
       index: true,
@@ -12,6 +13,6 @@ export const metadata: Metadata = {
   },
 };
 
-export default function Layout({ children }: { children: React.ReactNode }) {
+export default function Layout({ children }: PropsWithChildren) {
   return children;
 }

app/text/diff/page.tsx

@@ -5,16 +5,13 @@ import { Panel, PanelGroup } from "react-resizable-panels";
 
 import { PERSISTENCE_KEY } from "@/config/persistence-keys";
 import { toolGroups } from "@/config/tools";
-import { cn } from "@/lib/style";
 import { DiffEditor } from "@/components/ui/diff-editor";
 import { Editor } from "@/components/ui/editor";
 import * as Button from "@/components/buttons";
 import { Configuration } from "@/components/configuration";
 import { Configurations } from "@/components/configurations";
 import { ControlMenu } from "@/components/control-menu";
-import * as Icon from "@/components/icons";
 import * as icons from "@/components/icons";
-import { Rows } from "@/components/icons";
 import { LabeledSwitch } from "@/components/labeled-switch";
 import { PageRootSection } from "@/components/page-root-section";
 import { PageSection } from "@/components/page-section";
@@ -69,6 +66,7 @@ export default function Page() {
     ),
     [setInput1, clearInput1]
   );
+
   const input2Control = useMemo(
     () => (
       <ControlMenu
@@ -93,16 +91,15 @@ export default function Page() {
     [diffFullHeight, toggleFullHeight]
   );
 
+  const hiddenInFullHeightMode = useMemo(() => (diffFullHeight ? "hidden" : ""), [diffFullHeight]);
+
   return (
-    <PageRootSection
-      className="h-full"
-      title={toolGroups.text.tools.inspector_and_case_converter.longTitle}
-    >
-      <PageSection title="Configuration" className={cn(diffFullHeight && "hidden")}>
+    <PageRootSection className="h-full" title={toolGroups.text.tools.diff.longTitle}>
+      <PageSection title="Configuration" className={hiddenInFullHeightMode}>
         <Configurations list={[inlineModeConfig]} />
       </PageSection>
       <PanelGroup direction="vertical" autoSaveId={PERSISTENCE_KEY.panels.textDiff.vertical}>
-        <Panel maxSize={VERTICAL_PANEL_MAX_SIZE} className={cn(diffFullHeight && "hidden")}>
+        <Panel maxSize={VERTICAL_PANEL_MAX_SIZE} className={hiddenInFullHeightMode}>
           <PanelGroup
             direction="horizontal"
             autoSaveId={PERSISTENCE_KEY.panels.textDiff.horizontal}
@@ -121,7 +118,7 @@ export default function Page() {
             </Panel>
           </PanelGroup>
         </Panel>
-        <PanelResizeHandle direction="horizontal" className={cn(diffFullHeight && "hidden")} />
+        <PanelResizeHandle direction="horizontal" className={hiddenInFullHeightMode} />
         <Panel maxSize={diffPanelMaxSize}>
           <PageSection className="h-full" title="Difference" control={diffControl}>
             <DiffEditor

components/ui/diff-editor.tsx

@@ -0,0 +1,30 @@
+"use client";
+
+import { ComponentPropsWithoutRef, forwardRef } from "react";
+import { DiffEditor as MonacoDiffEditor } from "@monaco-editor/react";
+import { useTheme } from "next-themes";
+
+export type EditorProps = ComponentPropsWithoutRef<typeof MonacoDiffEditor>;
+
+export const DiffEditor = forwardRef<HTMLTextAreaElement, EditorProps>(
+  ({ options, theme, ...props }, ref) => {
+    const { theme: appTheme } = useTheme();
+    const themeToUse = theme ?? (appTheme === "light" ? "light" : "vs-dark");
+
+    return (
+      <MonacoDiffEditor
+        {...{ ref }}
+        theme={themeToUse}
+        options={{
+          tabFocusMode: true,
+          automaticLayout: true,
+          scrollBeyondLastLine: false,
+          ...options, // NOTE: merge shallowly
+        }}
+        {...props}
+      />
+    );
+  }
+);
+
+DiffEditor.displayName = "Editor";

config/tools.ts

@@ -139,10 +139,10 @@ export const toolGroups = {
       },
       diff: {
         Icon: icons.Diff,
-        shortTitle: "Text diff",
-        longTitle: "Text Inspector & Case Converter",
-        description: "Analyze text and convert it to a different case",
-        keywords: "case converter convert text inspector inspect",
+        shortTitle: "Text Diff",
+        longTitle: "Text Comparer",
+        description: "Compare two texts and highlight the differences",
+        keywords: "text comparer compare diff highlight",
         href: "/text/diff",
       },
     },