feat: support gfm alerts (#84)

deno.json

@@ -5,5 +5,8 @@
     "test": "deno test --allow-read",
     "coverage": "deno test --allow-read --coverage=cov_profile"
   },
+  "fmt": {
+    "exclude": ["./test/fixtures/alerts.md"]
+  },
   "lock": false
 }

deps.ts

@@ -11,6 +11,8 @@ export * as Marked from "https://esm.sh/[email protected]?pin=v135";
 
 export { default as GitHubSlugger } from "https://esm.sh/[email protected]?pin=v135";
 
+export { default as markedAlert } from "https://esm.sh/[email protected]?pin=v135";
+
 export { gfmHeadingId } from "https://esm.sh/[email protected]?pin=v135";
 
 export { default as Prism } from "https://esm.sh/[email protected]?pin=v135";

mod.ts

@@ -5,12 +5,14 @@ import {
   htmlEscape,
   katex,
   Marked,
+  markedAlert,
   Prism,
   sanitizeHtml,
 } from "./deps.ts";
 import { CSS, KATEX_CLASSES, KATEX_CSS } from "./style.js";
 export { CSS, KATEX_CSS, Marked };
 
+Marked.marked.use(markedAlert());
 Marked.marked.use(gfmHeadingId());
 
 const slugger = new GitHubSlugger();
@@ -58,6 +60,7 @@ export class Renderer extends Marked.Renderer {
     const html = Prism.highlight(code, grammar, language!);
     return `<div class="highlight highlight-source-${language} notranslate"><pre>${html}</pre></div>`;
   }
+
   link(href: string, title: string | null, text: string) {
     const titleAttr = title ? ` title="${title}"` : "";
     if (href.startsWith("#")) {
@@ -232,7 +235,13 @@ export function render(markdown: string, opts: RenderOptions = {}): string {
       annotation: ["encoding"], // Only enabled when math is enabled
     },
     allowedClasses: {
-      div: ["highlight", "highlight-source-*", "notranslate"],
+      div: [
+        "highlight",
+        "highlight-source-*",
+        "notranslate",
+        "markdown-alert",
+        "markdown-alert-*",
+      ],
       span: [
         "token",
         "keyword",
@@ -259,7 +268,8 @@ export function render(markdown: string, opts: RenderOptions = {}): string {
         ...(opts.allowMath ? KATEX_CLASSES : []),
       ],
       a: ["anchor"],
-      svg: ["octicon", "octicon-link"],
+      p: ["markdown-alert-title"],
+      svg: ["octicon", "octicon-alert", "octicon-link"],
     },
     allowProtocolRelative: false,
   });

test/fixtures/alerts.html

@@ -0,0 +1,21 @@
+<h1 id="alerts"><a class="anchor" aria-hidden="true" tabindex="-1" href="#alerts"><svg class="octicon octicon-link" viewbox="0 0 16 16" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M7.775 3.275a.75.75 0 001.06 1.06l1.25-1.25a2 2 0 112.83 2.83l-2.5 2.5a2 2 0 01-2.83 0 .75.75 0 00-1.06 1.06 3.5 3.5 0 004.95 0l2.5-2.5a3.5 3.5 0 00-4.95-4.95l-1.25 1.25zm-4.69 9.64a2 2 0 010-2.83l2.5-2.5a2 2 0 012.83 0 .75.75 0 001.06-1.06 3.5 3.5 0 00-4.95 0l-2.5 2.5a3.5 3.5 0 004.95 4.95l1.25-1.25a.75.75 0 00-1.06-1.06l-1.25 1.25a2 2 0 01-2.83 0z"></path></svg></a>Alerts</h1><div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title"><svg class="octicon" viewbox="0 0 16 16" width="16" height="16" aria-hidden="true"><path d="M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Note</p>
+<p>Highlights information that users should take into account, even when
+skimming.</p>
+</div>
+<div class="markdown-alert markdown-alert-tip">
+<p class="markdown-alert-title"><svg class="octicon" viewbox="0 0 16 16" width="16" height="16" aria-hidden="true"><path d="M8 1.5c-2.363 0-4 1.69-4 3.75 0 .984.424 1.625.984 2.304l.214.253c.223.264.47.556.673.848.284.411.537.896.621 1.49a.75.75 0 0 1-1.484.211c-.04-.282-.163-.547-.37-.847a8.456 8.456 0 0 0-.542-.68c-.084-.1-.173-.205-.268-.32C3.201 7.75 2.5 6.766 2.5 5.25 2.5 2.31 4.863 0 8 0s5.5 2.31 5.5 5.25c0 1.516-.701 2.5-1.328 3.259-.095.115-.184.22-.268.319-.207.245-.383.453-.541.681-.208.3-.33.565-.37.847a.751.751 0 0 1-1.485-.212c.084-.593.337-1.078.621-1.489.203-.292.45-.584.673-.848.075-.088.147-.173.213-.253.561-.679.985-1.32.985-2.304 0-2.06-1.637-3.75-4-3.75ZM5.75 12h4.5a.75.75 0 0 1 0 1.5h-4.5a.75.75 0 0 1 0-1.5ZM6 15.25a.75.75 0 0 1 .75-.75h2.5a.75.75 0 0 1 0 1.5h-2.5a.75.75 0 0 1-.75-.75Z"></path></svg>Tip</p>
+<p>Optional information to help a user be more successful.</p>
+</div>
+<div class="markdown-alert markdown-alert-important">
+<p class="markdown-alert-title"><svg class="octicon" viewbox="0 0 16 16" width="16" height="16" aria-hidden="true"><path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v9.5A1.75 1.75 0 0 1 14.25 13H8.06l-2.573 2.573A1.458 1.458 0 0 1 3 14.543V13H1.75A1.75 1.75 0 0 1 0 11.25Zm1.75-.25a.25.25 0 0 0-.25.25v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25Zm7 2.25v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 9a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg>Important</p>
+<p>Crucial information necessary for users to succeed.</p>
+</div>
+<div class="markdown-alert markdown-alert-warning">
+<p class="markdown-alert-title"><svg class="octicon octicon-alert" viewbox="0 0 16 16" width="16" height="16" aria-hidden="true"><path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg>Warning</p>
+<p>Critical content demanding immediate user attention due to potential risks.</p>
+</div>
+<div class="markdown-alert markdown-alert-caution">
+<p class="markdown-alert-title"><svg class="octicon" viewbox="0 0 16 16" width="16" height="16" aria-hidden="true"><path d="M4.47.22A.749.749 0 0 1 5 0h6c.199 0 .389.079.53.22l4.25 4.25c.141.14.22.331.22.53v6a.749.749 0 0 1-.22.53l-4.25 4.25A.749.749 0 0 1 11 16H5a.749.749 0 0 1-.53-.22L.22 11.53A.749.749 0 0 1 0 11V5c0-.199.079-.389.22-.53Zm.84 1.28L1.5 5.31v5.38l3.81 3.81h5.38l3.81-3.81V5.31L10.69 1.5ZM8 4a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 4Zm0 8a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Caution</p>
+<p>Negative potential consequences of an action.</p>
+</div>

test/fixtures/alerts.md

@@ -0,0 +1,17 @@
+# Alerts
+
+> [!NOTE]
+> Highlights information that users should take into account, even when
+> skimming.
+
+> [!TIP]
+> Optional information to help a user be more successful.
+
+> [!IMPORTANT]
+> Crucial information necessary for users to succeed.
+
+> [!WARNING]
+> Critical content demanding immediate user attention due to potential risks.
+
+> [!CAUTION]
+> Negative potential consequences of an action.

test/test.ts

@@ -96,3 +96,13 @@ Deno.test(
     assertEquals(html, expected);
   },
 );
+
+Deno.test(
+  "alerts rendering",
+  async () => {
+    const markdown = await Deno.readTextFile("./test/fixtures/alerts.md");
+    const expected = await Deno.readTextFile("./test/fixtures/alerts.html");
+    const html = render(markdown);
+    assertEquals(html, expected);
+  },
+);