feat(cheddar): Render Markdown via Comrak r/282

Renders any ".md" file by pushing it through the Comrak rendering
pipeline.

This does not yet implement syntax highlighting of fenced blocks, but
we're getting there.

1 files changed, 24 insertions, 9 deletions

diff --git a/tools/cheddar/src/main.rs b/tools/cheddar/src/main.rs
index 76bf834cb806..7affc3bc9cf8 100644
--- a/tools/cheddar/src/main.rs
+++ b/tools/cheddar/src/main.rs
@@ -1,13 +1,15 @@
+use comrak::{markdown_to_html, ComrakOptions};
+use lazy_static::lazy_static;
 use std::env;
 use std::ffi::OsStr;
 use std::io::BufRead;
+use std::io::Read;
 use std::io;
 use std::path::Path;
-use syntect::easy::HighlightLines;
 use syntect::dumps::from_binary;
+use syntect::easy::HighlightLines;
 use syntect::highlighting::ThemeSet;
 use syntect::parsing::SyntaxSet;
-use lazy_static::lazy_static;
 
 use syntect::html::{
     append_highlighted_html_for_styled_line,
@@ -43,7 +45,26 @@ fn should_continue(res: &io::Result<usize>) -> bool {
 }
 
 fn format_markdown() {
-    unimplemented!("Not able to format Markdown just yet");
+    let mut buffer = String::new();
+    let stdin = io::stdin();
+    let mut stdin = stdin.lock();
+    stdin.read_to_string(&mut buffer).expect("failed to read stdin");
+
+    // Markdown rendering is configurd with most of the bells &
+    // whistles here:
+    let opts = ComrakOptions{
+        ext_strikethrough: true,
+        ext_tagfilter: true,
+        ext_table: true,
+        ext_autolink: true,
+        ext_tasklist: true,
+        ext_header_ids: Some(String::new()), // yyeeesss!
+        ext_footnotes: true,
+        ext_description_lists: true,
+        ..ComrakOptions::default()
+    };
+
+    print!("{}", markdown_to_html(&buffer, &opts));
 }
 
 fn format_code(extension: String) {
@@ -62,12 +83,6 @@ fn format_code(extension: String) {
         .or_else(|| SYNTAXES.find_syntax_by_first_line(&linebuf))
         .unwrap_or_else(|| SYNTAXES.find_syntax_plain_text());
 
-    // We're doing a completely different thing if the file is
-    // Markdown, so lets do that thing.
-    if syntax.name == "markdown" {
-
-    }
-
     let mut hl = HighlightLines::new(syntax, theme);
     let (mut outbuf, bg) = start_highlighted_html_snippet(theme);