fix: 修复长文档分页与滚动同步

apps/web/tests/mermaid-config.test.ts

@@ -11,6 +11,7 @@ describe("Mermaid 站点配置", () => {
     expect(config.look).toBe("classic");
     expect(config.securityLevel).toBe("strict");
     expect(config.startOnLoad).toBe(false);
+    expect(config.flowchart?.wrappingWidth).toBe(320);
   });
 
   it("锁定安全限制和原始主题 CSS", () => {

apps/web/tests/paged-break-token.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, it } from "vitest";
+import { resolveBreakTokenElement } from "../src/paged-break-token";
+
+describe("Paged.js 分页断点", () => {
+  it("直接返回元素断点", () => {
+    const element = {
+      nodeType: 1,
+      parentElement: null
+    } as unknown as Element;
+
+    expect(resolveBreakTokenElement(element)).toBe(element);
+  });
+
+  it("文本断点使用父元素继续查找", () => {
+    const parentElement = {} as Element;
+    const textNode = {
+      nodeType: 3,
+      parentElement
+    } as unknown as Node;
+
+    expect(resolveBreakTokenElement(textNode)).toBe(parentElement);
+  });
+
+  it("安全跳过空断点和无父元素节点", () => {
+    const detachedTextNode = {
+      nodeType: 3,
+      parentElement: null
+    } as unknown as Node;
+
+    expect(resolveBreakTokenElement(undefined)).toBeUndefined();
+    expect(
+      resolveBreakTokenElement(detachedTextNode)
+    ).toBeUndefined();
+  });
+});

apps/web/tests/paged-preview.test.ts

@@ -38,7 +38,12 @@ describe("分页预览协议", () => {
     expect(css).toContain("display: table-header-group");
     expect(css).toContain("break-inside: avoid");
     expect(css).toContain(".pagedjs_pages");
+    expect(css).toContain("padding: 34px 0");
+    expect(css).toContain('html[data-render-target="preview"]');
+    expect(css).toContain("overflow-x: hidden");
+    expect(css).toContain("overflow-y: scroll");
     expect(css).toContain('html[data-render-target="pdf"]');
+    expect(css).toContain("padding: 0");
     expect(css).toContain("break-after: page");
     expect(css).not.toContain("@media print");
   });

apps/web/tests/preview-page.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, it } from "vitest";
+import { getNearestPageNumber } from "../src/preview-page";
+
+const pages = [
+  { top: 0, bottom: 100 },
+  { top: 124, bottom: 224 },
+  { top: 248, bottom: 348 }
+];
+
+describe("getNearestPageNumber", () => {
+  it("返回视口中心所在的页面", () => {
+    expect(getNearestPageNumber(180, pages)).toBe(2);
+  });
+
+  it("在页间空隙中返回距离最近的页面", () => {
+    expect(getNearestPageNumber(110, pages)).toBe(1);
+    expect(getNearestPageNumber(116, pages)).toBe(2);
+  });
+
+  it("没有页面或中心坐标无效时返回 0", () => {
+    expect(getNearestPageNumber(20, [])).toBe(0);
+    expect(getNearestPageNumber(Number.NaN, pages)).toBe(0);
+  });
+});

apps/web/tests/scroll-sync.test.ts

@@ -0,0 +1,51 @@
+import { describe, expect, it } from "vitest";
+import {
+  getScrollProgress,
+  getSyncedScrollTop
+} from "../src/scroll-sync";
+
+describe("编辑与预览滚动同步", () => {
+  it("按可滚动范围计算阅读进度", () => {
+    expect(
+      getScrollProgress({
+        scrollTop: 600,
+        scrollHeight: 1600,
+        clientHeight: 400
+      })
+    ).toBe(0.5);
+  });
+
+  it("把源区域进度映射到目标区域", () => {
+    expect(
+      getSyncedScrollTop(
+        {
+          scrollTop: 600,
+          scrollHeight: 1600,
+          clientHeight: 400
+        },
+        {
+          scrollTop: 0,
+          scrollHeight: 5000,
+          clientHeight: 1000
+        }
+      )
+    ).toBe(2000);
+  });
+
+  it("处理无滚动范围和越界位置", () => {
+    expect(
+      getScrollProgress({
+        scrollTop: 100,
+        scrollHeight: 500,
+        clientHeight: 500
+      })
+    ).toBe(0);
+    expect(
+      getScrollProgress({
+        scrollTop: 1800,
+        scrollHeight: 1600,
+        clientHeight: 400
+      })
+    ).toBe(1);
+  });
+});