Implemented emoji aliases support in markdown files (#1194)

* Implemented emoji aliases support in markdown files

* Added emoji aliases rendering unit tests

* Added bench for emoji

Cargo.lock

@@ -761,6 +761,16 @@ dependencies = [
  "wasi 0.9.0+wasi-snapshot-preview1",
 ]
 
+[[package]]
+name = "gh-emoji"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a17a050b7eb420553344e1cf1db648e8b584c79e98b74e6e6d119eeedd9ddcbc"
+dependencies = [
+ "phf",
+ "regex",
+]
+
 [[package]]
 name = "gif"
 version = "0.11.1"
@@ -1975,6 +1985,7 @@ dependencies = [
  "config",
  "errors",
  "front_matter",
+ "gh-emoji",
  "lazy_static",
  "link_checker",
  "pest",

components/config/src/config/mod.rs

@@ -106,6 +106,9 @@ pub struct Config {
     /// The search config, telling what to include in the search index
     pub search: search::Search,
 
+    /// Whether to render emoji aliases (e.g.: :smile: => 😄) in the markdown files
+    pub emoji_rendering: bool,
+
     /// All user params set in [extra] in the config
     pub extra: HashMap<String, Toml>,
 }
@@ -337,6 +340,7 @@ impl Default for Config {
             slugify: slugify::Slugify::default(),
             search: search::Search::default(),
             extra: HashMap::new(),
+            emoji_rendering: false,
         }
     }
 }

components/rendering/Cargo.toml

@@ -15,6 +15,7 @@ pest = "2"
 pest_derive = "2"
 regex = "1"
 lazy_static = "1"
+gh-emoji = "1.0"
 
 errors = { path = "../errors" }
 front_matter = { path = "../front_matter" }

components/rendering/benches/all.rs

@@ -17,12 +17,12 @@ Lorem markdownum litora, care ponto nomina, et ut aspicit gelidas sui et
 purpureo genuit. Tamen colla venientis [delphina](http://nil-sol.com/ecquis)
 Tusci et temptata citaeque curam isto ubi vult vulnere reppulit.
 
-- Seque vidit flendoque de quodam
-- Dabit minimos deiecto caputque noctis pluma
-- Leti coniunx est Helicen
-- Illius pulvereumque Icare inpositos
-- Vivunt pereo pluvio tot ramos Olenios gelidis
-- Quater teretes natura inde
+- :one: Seque vidit flendoque de quodam
+- :two: Dabit minimos deiecto caputque noctis pluma
+- :three: Leti coniunx est Helicen
+- :four: Illius pulvereumque Icare inpositos
+- :five: Vivunt pereo pluvio tot ramos Olenios gelidis
+- :six: Quater teretes natura inde
 
 ### A subsection
 
@@ -35,7 +35,7 @@ granum captantur potuisse Minervae, frugum.
 > Clivo sub inprovisoque nostrum minus fama est, discordia patrem petebat precatur
 absumitur, poena per sit. Foramina *tamen cupidine* memor supplex tollentes
 dictum unam orbem, Anubis caecae. Viderat formosior tegebat satis, Aethiopasque
-sit submisso coniuge tristis ubi!
+sit submisso coniuge tristis ubi! :exclamation:
 
 ## Praeceps Corinthus totidem quem crus vultum cape
 
@@ -68,7 +68,7 @@ And a shortcode:
 ### Another subsection
 Gotta make the toc do a little bit of work
 
-# A big title
+# A big title :fire:
 
 - hello
 - world
@@ -123,3 +123,16 @@ fn bench_render_shortcodes_one_present(b: &mut test::Bencher) {
 
     b.iter(|| render_shortcodes(CONTENT, &context));
 }
+
+#[bench]
+fn bench_render_content_no_shortcode_with_emoji(b: &mut test::Bencher) {
+    let tera = Tera::default();
+    let content2 = CONTENT.replace(r#"{{ youtube(id="my_youtube_id") }}"#, "");
+    let mut config = Config::default();
+    config.highlight_code = false;
+    config.emoji_rendering = true;
+    let permalinks_ctx = HashMap::new();
+    let context = RenderContext::new(&tera, &config, "", &permalinks_ctx, InsertAnchor::None);
+
+    b.iter(|| render_content(&content2, &context).unwrap());
+}

components/rendering/src/markdown.rs

@@ -168,6 +168,10 @@ fn get_heading_refs(events: &[Event]) -> Vec<HeadingRef> {
 }
 
 pub fn markdown_to_html(content: &str, context: &RenderContext) -> Result<Rendered> {
+    lazy_static! {
+        static ref EMOJI_REPLACER: gh_emoji::Replacer = gh_emoji::Replacer::new();
+    }
+
     // the rendered html
     let mut html = String::with_capacity(content.len());
     // Set while parsing
@@ -197,11 +201,16 @@ pub fn markdown_to_html(content: &str, context: &RenderContext) -> Result<Render
                         if let Some(ref mut code_block) = highlighter {
                             let html = code_block.highlight(&text);
                             Event::Html(html.into())
+                        } else {
+                            if context.config.emoji_rendering {
+                                let processed_text = EMOJI_REPLACER.replace_all(&text);
+                                Event::Text(processed_text.to_string().into())
                             } else {
                                 // Business as usual
                                 Event::Text(text)
                             }
                         }
+                    }
                     Event::Start(Tag::CodeBlock(ref kind)) => {
                         let mut language = None;
                         match kind {

components/rendering/tests/markdown.rs

@@ -1036,3 +1036,28 @@ Again more text"#;
     let res = render_content(markdown_string, &context).unwrap();
     assert_eq!(res.body, expected);
 }
+
+#[test]
+fn can_render_emoji_alias() {
+    let permalinks_ctx = HashMap::new();
+    let mut config = Config::default();
+    config.emoji_rendering = true;
+    let context = RenderContext::new(&ZOLA_TERA, &config, "", &permalinks_ctx, InsertAnchor::None);
+    let res = render_content("Hello, World! :smile:", &context).unwrap();
+    assert_eq!(
+        res.body,
+        "<p>Hello, World! 😄</p>\n"
+    );
+}
+
+#[test]
+fn emoji_aliases_are_ignored_when_disabled_in_config() {
+    let permalinks_ctx = HashMap::new();
+    let config = Config::default();
+    let context = RenderContext::new(&ZOLA_TERA, &config, "", &permalinks_ctx, InsertAnchor::None);
+    let res = render_content("Hello, World! :smile:", &context).unwrap();
+    assert_eq!(
+        res.body,
+        "<p>Hello, World! :smile:</p>\n"
+    );
+}

docs/content/documentation/getting-started/configuration.md

@@ -61,6 +61,10 @@ generate_feed = false
 # files are always copied, regardless of this setting.
 # hard_link_static = false
 
+# When set to "true", emoji aliases translated to their corresponding
+# Unicode emoji equivalent in the rendered Markdown files. (e.g.: :smile: => 😄)
+# emoji_rendering = false
+
 # The taxonomies to be rendered for the site and their configuration.
 # Example:
 #     taxonomies = [