feat:代码变更diff可视化功能实现

src/utils/fileDiff.ts

@@ -0,0 +1,51 @@
+import * as vscode from "vscode";
+import * as path from "path";
+
+/**
+ * 将相对路径解析为工作区绝对路径
+ */
+export function resolveWorkspaceFilePath(filePath: string): string {
+  if (path.isAbsolute(filePath)) {
+    return filePath;
+  }
+
+  const workspaceFolders = vscode.workspace.workspaceFolders;
+  if (!workspaceFolders || workspaceFolders.length === 0) {
+    throw new Error("请先打开一个文件夹作为工作区，这样我就能为您修改文件了");
+  }
+
+  return path.join(workspaceFolders[0].uri.fsPath, filePath);
+}
+
+/**
+ * 使用 VS Code 原生 diff 视图展示文件修改前后对比
+ */
+export async function showFileDiff(
+  filePath: string,
+  oldContent: string,
+  title?: string
+): Promise<void> {
+  const absolutePath = resolveWorkspaceFilePath(filePath);
+  const fileUri = vscode.Uri.file(absolutePath);
+  const newBytes = await vscode.workspace.fs.readFile(fileUri);
+  const newContent = Buffer.from(newBytes).toString("utf-8");
+
+  if (oldContent === newContent) {
+    return;
+  }
+
+  const language = (await vscode.workspace.openTextDocument(fileUri)).languageId;
+  const oldDoc = await vscode.workspace.openTextDocument({
+    content: oldContent,
+    language,
+  });
+
+  const diffTitle = title || `${path.basename(absolutePath)} (修改前 <-> 修改后)`;
+  await vscode.commands.executeCommand(
+    "vscode.diff",
+    oldDoc.uri,
+    fileUri,
+    diffTitle,
+    { preview: false }
+  );
+}