3 files changed, 39 insertions, 4 deletions
diff --git a/vhosts/blog/nuldoc-src/jsx/types.d.ts b/vhosts/blog/nuldoc-src/jsx/types.d.ts
index 5d949d14..e47d7ffe 100644
--- a/vhosts/blog/nuldoc-src/jsx/types.d.ts
+++ b/vhosts/blog/nuldoc-src/jsx/types.d.ts
@@ -32,7 +32,11 @@ declare global {
       summary: IntrinsicElementType;
       updated: IntrinsicElementType;
       // HTML
-      a: IntrinsicElementType & { href?: string };
+      a: IntrinsicElementType & {
+        href?: string;
+        rel?: "noreferrer";
+        target?: "_blank";
+      };
       article: IntrinsicElementType;
       body: IntrinsicElementType;
       button: IntrinsicElementType;
diff --git a/vhosts/blog/nuldoc-src/ndoc/to_html.ts b/vhosts/blog/nuldoc-src/ndoc/to_html.ts
index ce55dbf9..bf556655 100644
--- a/vhosts/blog/nuldoc-src/ndoc/to_html.ts
+++ b/vhosts/blog/nuldoc-src/ndoc/to_html.ts
@@ -21,6 +21,7 @@ export default function toHtml(doc: Document): Document {
   transformSectionTitleElement(doc);
   transformCodeBlockElement(doc);
   transformNoteElement(doc);
+  addAttributesToExternalLinkElement(doc);
   setDefaultLangAttribute(doc);
   traverseFootnotes(doc);
   highlightPrograms(doc);
@@ -211,6 +212,22 @@ function transformNoteElement(doc: Document) {
   });
 }
 
+function addAttributesToExternalLinkElement(doc: Document) {
+  forEachChildRecursively(doc.root, (n) => {
+    if (n.kind !== "element" || n.name !== "a") {
+      return;
+    }
+
+    const href = n.attributes.get("href") ?? "";
+    if (!href.startsWith("http")) {
+      return;
+    }
+    n.attributes
+      .set("target", "_blank")
+      .set("rel", "noreferrer");
+  });
+}
+
 function setDefaultLangAttribute(_doc: Document) {
   // TODO
   // if (!e.attributes.has("lang")) {
diff --git a/vhosts/blog/nuldoc-src/pages/AboutPage.tsx b/vhosts/blog/nuldoc-src/pages/AboutPage.tsx
index 0000edf5..48763821 100644
--- a/vhosts/blog/nuldoc-src/pages/AboutPage.tsx
+++ b/vhosts/blog/nuldoc-src/pages/AboutPage.tsx
@@ -44,12 +44,22 @@ export default function AboutPage(
                 <h2>アカウント</h2>
                 <ul>
                   <li>
-                    <a href="https://twitter.com/nsfisis">
+                    <a
+                      href="https://twitter.com/nsfisis"
+                      target="_blank"
+                      rel="noreferrer"
+                    >
                       Twitter (現 𝕏): @nsfisis
                     </a>
                   </li>
                   <li>
-                    <a href="https://github.com/nsfisis">GitHub: @nsfisis</a>
+                    <a
+                      href="https://github.com/nsfisis"
+                      target="_blank"
+                      rel="noreferrer"
+                    >
+                      GitHub: @nsfisis
+                    </a>
                   </li>
                 </ul>
               </section>
@@ -58,7 +68,11 @@ export default function AboutPage(
                 <ul>
                   <li>
                     {"2021-01～現在: "}
-                    <a href="https://www.dgcircus.com/">
+                    <a
+                      href="https://www.dgcircus.com/"
+                      target="_blank"
+                      rel="noreferrer"
+                    >
                       デジタルサーカス株式会社
                     </a>
                   </li>