feat(import/markdown): collapse unnecessary whitespace when importing

src/services/import/markdown.spec.ts

@@ -56,4 +56,22 @@ describe("markdown", () => {
         `, "What's new")
         expect(result).toBe(`\n<p>Hi there</p>\n`);
     });
+
+    it("trims unnecessary whitespace", () => {
+        const input = `\
+## Heading 1
+
+Title
+
+\`\`\`
+code block 1
+second line 2
+\`\`\`
+`;
+        const expected = `\
+<h2>Heading 1</h2><p>Title</p><pre><code class="language-text-x-trilium-auto">code block 1
+second line 2</code></pre>`;
+        expect(markdownService.renderToHtml(input, "Troubleshooting")).toBe(expected);
+    });
+
 });

src/services/import/markdown.ts

@@ -1,6 +1,7 @@
 "use strict";
 
 import { parse, Renderer, type Tokens } from "marked";
+import { minify as minifyHtml } from "html-minifier";
 
 const renderer = new Renderer({ async: false });
 renderer.code = ({ text, lang, escaped }: Tokens.Code) => {
@@ -17,12 +18,19 @@ import importUtils from "./utils.js";
 import { getMimeTypeFromHighlightJs, MIME_TYPE_AUTO, normalizeMimeTypeForCKEditor } from "./mime_type_definitions.js";
 
 function renderToHtml(content: string, title: string) {
-    const html = parse(content, {
+    let html = parse(content, {
         async: false,
         renderer: renderer
     }) as string;
-    const h1Handled = importUtils.handleH1(html, title); // h1 handling needs to come before sanitization
-    return htmlSanitizer.sanitize(h1Handled);
+
+    // h1 handling needs to come before sanitization
+    html = importUtils.handleH1(html, title);
+    html = htmlSanitizer.sanitize(html);
+    html = minifyHtml(html, {
+        collapseWhitespace: true
+    });
+
+    return html;
 }
 
 function getNormalizedMimeFromMarkdownLanguage(language: string | undefined) {