From 3e1f5777f131319873378654659923b749ca23dc Mon Sep 17 00:00:00 2001
From: Kartavya Vashishtha <sendtokartavya@gmail.com>
Date: Sat, 11 Feb 2023 19:42:40 +0530
Subject: [PATCH] feat: External URL redirect (#2080)

---
 components/content/src/section.rs   | 28 ++++++++++++++++++++++++++++
 components/markdown/src/markdown.rs |  6 +-----
 components/site/src/lib.rs          |  9 +++++++--
 components/utils/src/net.rs         |  5 +++++
 4 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/components/content/src/section.rs b/components/content/src/section.rs
index f5695bad..920f863e 100644
--- a/components/content/src/section.rs
+++ b/components/content/src/section.rs
@@ -7,6 +7,7 @@ use config::Config;
 use errors::{Context, Result};
 use markdown::{render_content, RenderContext};
 use utils::fs::read_file;
+use utils::net::is_external_link;
 use utils::table_of_contents::Heading;
 use utils::templates::{render_template, ShortcodeDefinition};
 
@@ -168,7 +169,14 @@ impl Section {
             .with_context(|| format!("Failed to render content of {}", self.file.path.display()))?;
         self.content = res.body;
         self.toc = res.toc;
+
         self.external_links = res.external_links;
+        if let Some(ref redirect_to) = self.meta.redirect_to {
+            if is_external_link(redirect_to) {
+                self.external_links.push(redirect_to.to_owned());
+            }
+        }
+
         self.internal_links = res.internal_links;
 
         Ok(())
@@ -356,4 +364,24 @@ Bonjour le monde"#
         assert_eq!(section.lang, "fr".to_string());
         assert_eq!(section.permalink, "http://a-website.com/fr/subcontent/");
     }
+
+    #[test]
+    fn can_redirect_to_external_site() {
+        let config = Config::default();
+        let content = r#"
++++
+redirect_to = "https://bar.com/something"
++++
+Example"#
+            .to_string();
+        let res = Section::parse(
+            Path::new("content/subcontent/_index.md"),
+            &content,
+            &config,
+            &PathBuf::new(),
+        );
+        assert!(res.is_ok());
+        let section = res.unwrap();
+        assert_eq!(section.meta.redirect_to, Some("https://bar.com/something".to_owned()));
+    }
 }
diff --git a/components/markdown/src/markdown.rs b/components/markdown/src/markdown.rs
index 6d66f88d..d773a21f 100644
--- a/components/markdown/src/markdown.rs
+++ b/components/markdown/src/markdown.rs
@@ -5,6 +5,7 @@ use libs::gh_emoji::Replacer as EmojiReplacer;
 use libs::once_cell::sync::Lazy;
 use libs::pulldown_cmark as cmark;
 use libs::tera;
+use utils::net::is_external_link;
 
 use crate::context::RenderContext;
 use errors::{Context, Error, Result};
@@ -133,11 +134,6 @@ fn find_anchor(anchors: &[String], name: String, level: u16) -> String {
     find_anchor(anchors, name, level + 1)
 }
 
-/// Returns whether a link starts with an HTTP(s) scheme.
-fn is_external_link(link: &str) -> bool {
-    link.starts_with("http:") || link.starts_with("https:")
-}
-
 fn fix_link(
     link_type: LinkType,
     link: &str,
diff --git a/components/site/src/lib.rs b/components/site/src/lib.rs
index e0005b61..67ca956e 100644
--- a/components/site/src/lib.rs
+++ b/components/site/src/lib.rs
@@ -5,6 +5,7 @@ pub mod sass;
 pub mod sitemap;
 pub mod tpls;
 
+use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::fs::{remove_dir_all, remove_file};
 use std::path::{Path, PathBuf};
@@ -25,7 +26,7 @@ use utils::fs::{
     copy_directory, copy_file_if_needed, create_directory, create_file, ensure_directory_exists,
     is_dotfile,
 };
-use utils::net::get_available_port;
+use utils::net::{get_available_port, is_external_link};
 use utils::templates::{render_template, ShortcodeDefinition};
 use utils::types::InsertAnchor;
 
@@ -1142,7 +1143,11 @@ impl Site {
         }
 
         if let Some(ref redirect_to) = section.meta.redirect_to {
-            let permalink = self.config.make_permalink(redirect_to);
+            let permalink: Cow<String> = if is_external_link(redirect_to) {
+                Cow::Borrowed(redirect_to)
+            } else {
+                Cow::Owned(self.config.make_permalink(redirect_to))
+            };
             self.write_content(
                 &components,
                 "index.html",
diff --git a/components/utils/src/net.rs b/components/utils/src/net.rs
index 314ec8e9..9f662e85 100644
--- a/components/utils/src/net.rs
+++ b/components/utils/src/net.rs
@@ -9,3 +9,8 @@ pub fn get_available_port(avoid: u16) -> Option<u16> {
 pub fn port_is_available(port: u16) -> bool {
     TcpListener::bind(("127.0.0.1", port)).is_ok()
 }
+
+/// Returns whether a link starts with an HTTP(s) scheme.
+pub fn is_external_link(link: &str) -> bool {
+    link.starts_with("http:") || link.starts_with("https:")
+}