feat: 完善 Mermaid 配置与预览缩放

apps/web/tests/export-settings.test.ts

@@ -2,24 +2,32 @@ import { describe, expect, it } from "vitest";
 import { defaultExportConfig } from "@md-to-pdf/core";
 import {
   EXPORT_CONFIG_STORAGE_KEY,
+  LEGACY_EXPORT_CONFIG_STORAGE_KEY,
   loadExportConfig,
   parseStoredExportConfig,
   saveExportConfig
 } from "../src/export-settings";
 
-function createMemoryStorage(initialValue: string | null = null) {
-  let value = initialValue;
+function createMemoryStorage(
+  initialValue: string | null = null,
+  legacyValue: string | null = null
+) {
+  const values = new Map<string, string>();
+  if (initialValue) {
+    values.set(EXPORT_CONFIG_STORAGE_KEY, initialValue);
+  }
+  if (legacyValue) {
+    values.set(LEGACY_EXPORT_CONFIG_STORAGE_KEY, legacyValue);
+  }
   return {
     getItem(key: string) {
-      return key === EXPORT_CONFIG_STORAGE_KEY ? value : null;
+      return values.get(key) ?? null;
     },
     setItem(key: string, nextValue: string) {
-      if (key === EXPORT_CONFIG_STORAGE_KEY) {
-        value = nextValue;
-      }
+      values.set(key, nextValue);
     },
     read() {
-      return value;
+      return values.get(EXPORT_CONFIG_STORAGE_KEY) ?? null;
     }
   };
 }
@@ -44,6 +52,28 @@ describe("导出设置缓存", () => {
     ).toEqual(defaultExportConfig);
   });
 
+  it("将 v2 缓存迁移为 v3 并保留已有设置", () => {
+    const legacyConfig = {
+      ...defaultExportConfig,
+      version: 2,
+      mermaid: undefined,
+      paper: {
+        ...defaultExportConfig.paper,
+        format: "A5"
+      }
+    };
+    const storage = createMemoryStorage(
+      null,
+      JSON.stringify(legacyConfig)
+    );
+
+    const migrated = loadExportConfig(storage);
+    expect(migrated.version).toBe(3);
+    expect(migrated.paper.format).toBe("A5");
+    expect(migrated.mermaid).toEqual(defaultExportConfig.mermaid);
+    expect(storage.read()).toContain('"version":3');
+  });
+
   it("保存并恢复经过校验的配置", () => {
     const storage = createMemoryStorage();
     const config = {