From 97f35095caaf617241fae7e77149aa383f332c49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Heinrichs?= <manfie@protonmail.ch>
Date: Sat, 25 Apr 2026 03:43:22 -0400
Subject: [PATCH] Feature md link blanks (#660)

Co-authored-by: GCHQDeveloper581 <63102987+GCHQDeveloper581@users.noreply.github.com> (added tests)
---
 src/core/operations/RenderMarkdown.mjs    |  39 +++++++-
 tests/operations/index.mjs                |   1 +
 tests/operations/tests/RenderMarkdown.mjs | 110 ++++++++++++++++++++++
 3 files changed, 146 insertions(+), 4 deletions(-)
 create mode 100644 tests/operations/tests/RenderMarkdown.mjs

diff --git a/src/core/operations/RenderMarkdown.mjs b/src/core/operations/RenderMarkdown.mjs
index c656bf5b..20966cca 100644
--- a/src/core/operations/RenderMarkdown.mjs
+++ b/src/core/operations/RenderMarkdown.mjs
@@ -35,6 +35,11 @@ class RenderMarkdown extends Operation {
                 name: "Enable syntax highlighting",
                 type: "boolean",
                 value: true
+            },
+            {
+                name: "Open links in new tab.",
+                type: "boolean",
+                value: false
             }
         ];
     }
@@ -45,7 +50,7 @@ class RenderMarkdown extends Operation {
      * @returns {html}
      */
     run(input, args) {
-        const [convertLinks, enableHighlighting] = args,
+        const [convertLinks, enableHighlighting, openLinksBlank] = args,
             md = new MarkdownIt({
                 linkify: convertLinks,
                 html: false, // Explicitly disable HTML rendering
@@ -58,12 +63,38 @@ class RenderMarkdown extends Operation {
 
                     return "";
                 }
-            }),
-            rendered = md.render(input);
-
+            });
+        if (openLinksBlank) {
+            this.makeLinksOpenInNewTab(md);
+        }
+        const rendered = md.render(input);
         return `<div style="font-family: var(--primary-font-family)">${rendered}</div>`;
     }
 
+    /**
+     * Adds target="_blank" to links.
+     * @param {MarkdownIt} md
+     */
+    makeLinksOpenInNewTab(md) {
+        // Adapted from: https://github.com/markdown-it/markdown-it/blob/master/docs/architecture.md#renderer
+        // Remember old renderer, if overridden, or proxy to default renderer
+        const defaultRender = md.renderer.rules.link_open || function(tokens, idx, options, env, self) {
+            return self.renderToken(tokens, idx, options);
+        };
+
+        // eslint-disable-next-line camelcase
+        md.renderer.rules.link_open = function (tokens, idx, options, env, self) {
+            const token = tokens[idx];
+            if (token.attrIndex("target") >= 0) {
+                // Target attribute already set, do not replace.
+                return;
+            }
+            token.attrPush(["target", "_blank"]); // add new attribute
+
+            // pass token to default renderer.
+            return defaultRender(tokens, idx, options, env, self);
+        };
+    }
 }
 
 export default RenderMarkdown;
diff --git a/tests/operations/index.mjs b/tests/operations/index.mjs
index 420d0129..f40d840e 100644
--- a/tests/operations/index.mjs
+++ b/tests/operations/index.mjs
@@ -145,6 +145,7 @@ import "./tests/RAKE.mjs";
 import "./tests/Regex.mjs";
 import "./tests/Register.mjs";
 import "./tests/RegularExpression.mjs";
+import "./tests/RenderMarkdown.mjs";
 import "./tests/RisonEncodeDecode.mjs";
 import "./tests/Rotate.mjs";
 import "./tests/RSA.mjs";
diff --git a/tests/operations/tests/RenderMarkdown.mjs b/tests/operations/tests/RenderMarkdown.mjs
new file mode 100644
index 00000000..47781e5e
--- /dev/null
+++ b/tests/operations/tests/RenderMarkdown.mjs
@@ -0,0 +1,110 @@
+/**
+ * RenderMarkdown tests.
+ *
+ * @copyright Crown Copyright 2026
+ * @license Apache-2.0
+ */
+
+import TestRegister from "../../lib/TestRegister.mjs";
+
+TestRegister.addTests([
+    {
+        name: "Render Markdown: Nothing",
+        input: "",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"></div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": []
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: Basic Text",
+        input: "Hello World!",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><p>Hello World!</p>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": []
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: Simple Markdown",
+        input: "# Hello World!",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><h1>Hello World!</h1>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": []
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: URL (not expanded)",
+        input: "https://gchq.github.io/CyberChef/",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><p>https://gchq.github.io/CyberChef/</p>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": [false, false, false]
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: URL (expanded)",
+        input: "https://gchq.github.io/CyberChef/",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><p><a href="https://gchq.github.io/CyberChef/">https://gchq.github.io/CyberChef/</a></p>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": [true, false, false]
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: Link (not expanded)",
+        input: "[CyberChef](https://gchq.github.io/CyberChef/)",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><p><a href="https://gchq.github.io/CyberChef/">CyberChef</a></p>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": [false, false, false]
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: Link (expanded)",
+        input: "[CyberChef](https://gchq.github.io/CyberChef/)",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><p><a href="https://gchq.github.io/CyberChef/">CyberChef</a></p>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": [true, false, false]
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: Link (open in new window)",
+        input: "[CyberChef](https://gchq.github.io/CyberChef/)",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><p><a href="https://gchq.github.io/CyberChef/" target="_blank">CyberChef</a></p>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": [true, false, true]
+            }
+        ]
+    },
+    {
+        name: "Render Markdown: URL (open in new window)",
+        input: "https://gchq.github.io/CyberChef/",
+        expectedOutput: '<div style="font-family: var(--primary-font-family)"><p><a href="https://gchq.github.io/CyberChef/" target="_blank">https://gchq.github.io/CyberChef/</a></p>\n</div>',
+        recipeConfig: [
+            {
+                "op": "Render Markdown",
+                "args": [true, false, true]
+            }
+        ]
+    },
+]);