Upload code block in case of incompatible backtick

m2d/converters/event-to-message.js

@@ -181,7 +181,7 @@ turndownService.addRule("fencedCodeBlock", {
 		const className = node.firstChild.getAttribute("class") || ""
 		const language = (className.match(/language-(\S+)/) || [null, ""])[1]
 		const code = node.firstChild
-		const visibleCode = code.childNodes.map(c => c.nodeName === "BR" ? "\n" : c.textContent).join("").replace(/\n*$/g, "")
+		const visibleCode = getCodeContent(code)
 
 		var fence = "```"
 
@@ -193,6 +193,11 @@ turndownService.addRule("fencedCodeBlock", {
 	}
 })
 
+/** @param {{ childNodes: Node[]; }} preCode the <code> directly inside the <pre> */
+function getCodeContent(preCode) {
+	return preCode.childNodes.map(c => c.nodeName === "BR" ? "\n" : c.textContent).join("").replace(/\n*$/g, "")
+}
+
 /**
  * @param {string | null} mxcUrl
  * @param {string | null} nameForGuess without colons
@@ -308,7 +313,7 @@ async function uploadEndOfMessageSpriteSheet(content, attachments, pendingFiles)
 	const buffer = await emojiSheet.compositeMatrixEmojis(endOfMessageEmojis)
 	// Attach it
 	const name = "emojis.png"
-	attachments.push({id: "0", name})
+	attachments.push({id: String(attachments.length), name})
 	pendingFiles.push({name, buffer})
 	return content
 }
@@ -393,6 +398,16 @@ async function checkWrittenMentions(content, guild, di) {
 	}
 }
 
+/**
+ * @param {Element} node
+ * @param {string[]} tagNames allcaps tag names
+ * @returns {any | undefined} the node you were checking for, or undefined
+ */
+function nodeIsChildOf(node, tagNames) {
+	// @ts-ignore
+	for (; node; node = node.parentNode) if (tagNames.includes(node.tagName)) return node
+}
+
 const attachmentEmojis = new Map([
 	["m.image", "🖼️"],
 	["m.video", "🎞️"],
@@ -651,20 +666,38 @@ async function eventToMessage(event, guild, di) {
 			const root = doc.getElementById("turndown-root");
 			async function forEachNode(node) {
 				for (; node; node = node.nextSibling) {
-					if (node.nodeType === 3 && node.nodeValue.includes("@")) {
+					// Check written mentions
+					if (node.nodeType === 3 && node.nodeValue.includes("@") && !nodeIsChildOf(node, ["A", "CODE", "PRE"])) {
 						const result = await checkWrittenMentions(node.nodeValue, guild, di)
 						if (result) {
 							node.nodeValue = result.content
 							ensureJoined.push(result.ensureJoined)
 						}
 					}
-					if (node.nodeType === 1 && ["CODE", "PRE", "A"].includes(node.tagName)) {
+					// Check for incompatible backticks in code blocks
-						// don't recurse into code or links
+					let preNode
-					} else {
+					if (node.nodeType === 3 && node.nodeValue.includes("```") && (preNode = nodeIsChildOf(node, ["PRE"]))) {
-						// do recurse into everything else
+						if (preNode.firstChild?.nodeName === "CODE") {
-						await forEachNode(node.firstChild)
+							const ext = (preNode.firstChild.className.match(/language-(\S+)/) || [null, "txt"])[1]
+							const filename = `inline_code.${ext}`
+							// Build the replacement <code> node
+							const replacementCode = doc.createElement("code")
+							replacementCode.textContent = `[${filename}]`
+							// Build its containing <span> node
+							const replacement = doc.createElement("span")
+							replacement.appendChild(doc.createTextNode(" "))
+							replacement.appendChild(replacementCode)
+							replacement.appendChild(doc.createTextNode(" "))
+							// Replace the code block with the <span>
+							preNode.replaceWith(replacement)
+							// Upload the code as an attachment
+							const content = getCodeContent(preNode.firstChild)
+							attachments.push({id: String(attachments.length), filename})
+							pendingFiles.push({name: filename, buffer: Buffer.from(content, "utf8")})
 						}
 					}
+					await forEachNode(node.firstChild)
+				}
 			}
 			await forEachNode(root)
 

m2d/converters/event-to-message.test.js

@@ -517,21 +517,16 @@ test("event2message: code blocks work", async t => {
 test("event2message: code block contents are formatted correctly and not escaped", async t => {
 	t.deepEqual(
 		await eventToMessage({
-			"type": "m.room.message",
+			type: "m.room.message",
-			"sender": "@cadence:cadence.moe",
+			sender: "@cadence:cadence.moe",
-			"content": {
+			content: {
-				"msgtype": "m.text",
+				msgtype: "m.text",
-				"body": "wrong body",
+				body: "wrong body",
-				"format": "org.matrix.custom.html",
+				format: "org.matrix.custom.html",
-				"formatted_body": "<pre><code>input = input.replace(/(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?\\n(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?/g,\n_input_ = input = input.replace(/(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?\\n(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?/g,\n</code></pre>\n<p><code>input = input.replace(/(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?\\n(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?/g,</code></p>\n"
+				formatted_body: "<pre><code>input = input.replace(/(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?\\n(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?/g,\n_input_ = input = input.replace(/(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?\\n(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?/g,\n</code></pre>\n<p><code>input = input.replace(/(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?\\n(&lt;\\/?([^ &gt;]+)[^&gt;]*&gt;)?/g,</code></p>\n"
 			},
-			"origin_server_ts": 1693031482275,
+			event_id: "$pGkWQuGVmrPNByrFELxhzI6MCBgJecr5I2J3z88Gc2s",
-			"unsigned": {
+			room_id: "!BpMdOUkWWhFxmTrENV:cadence.moe"
-				"age": 99,
-				"transaction_id": "m1693031482146.511"
-			},
-			"event_id": "$pGkWQuGVmrPNByrFELxhzI6MCBgJecr5I2J3z88Gc2s",
-			"room_id": "!BpMdOUkWWhFxmTrENV:cadence.moe"
 		}),
 		{
 			ensureJoined: [],
@@ -546,6 +541,75 @@ test("event2message: code block contents are formatted correctly and not escaped
 	)
 })
 
+test("event2message: code blocks are uploaded as attachments instead if they contain incompatible backticks", async t => {
+	t.deepEqual(
+		await eventToMessage({
+			type: "m.room.message",
+			sender: "@cadence:cadence.moe",
+			content: {
+				msgtype: "m.text",
+				body: "wrong body",
+				format: "org.matrix.custom.html",
+				formatted_body: 'So if you run code like this<pre><code class="language-java">System.out.println("```");</code></pre>it should print a markdown formatted code block'
+			},
+			event_id: "$pGkWQuGVmrPNByrFELxhzI6MCBgJecr5I2J3z88Gc2s",
+			room_id: "!BpMdOUkWWhFxmTrENV:cadence.moe"
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "cadence [they]",
+				content: "So if you run code like this `[inline_code.java]` it should print a markdown formatted code block",
+				attachments: [{id: "0", filename: "inline_code.java"}],
+				pendingFiles: [{name: "inline_code.java", buffer: Buffer.from('System.out.println("```");')}],
+				avatar_url: undefined
+			}]
+		}
+	)
+})
+
+test("event2message: characters are encoded properly in code blocks", async t => {
+	t.deepEqual(
+		await eventToMessage({
+			type: "m.room.message",
+			sender: "@cadence:cadence.moe",
+			content: {
+				msgtype: "m.text",
+				body: "wrong body",
+				format: "org.matrix.custom.html",
+				formatted_body: '<pre><code class="rs language-rs">fn extract_diff(chat_response: &amp;str) -&gt; Result&lt;String&gt; {'
+					+ '\n    let fragments = regex!(r#"^```diff.*?^(.*?)^```.*?($|\\z)"#sm)'
+					+ '\n        .captures_iter(chat_response)'
+					+ '\n        .map(|c| c.get(1).unwrap().as_str())'
+					+ '\n        .collect::&lt;String&gt;();'
+			  		+ '\n</code></pre>'
+			},
+			event_id: "$pGkWQuGVmrPNByrFELxhzI6MCBgJecr5I2J3z88Gc2s",
+			room_id: "!BpMdOUkWWhFxmTrENV:cadence.moe"
+		}),
+		{
+			ensureJoined: [],
+			messagesToDelete: [],
+			messagesToEdit: [],
+			messagesToSend: [{
+				username: "cadence [they]",
+				content: "`[inline_code.rs]`",
+				attachments: [{id: "0", filename: "inline_code.rs"}],
+				pendingFiles: [{name: "inline_code.rs", buffer: Buffer.from(
+					'fn extract_diff(chat_response: &str) -> Result<String> {'
+					+ '\n    let fragments = regex!(r#"^```diff.*?^(.*?)^```.*?($|\\z)"#sm)'
+					+ '\n        .captures_iter(chat_response)'
+					+ '\n        .map(|c| c.get(1).unwrap().as_str())'
+					+ '\n        .collect::<String>();'
+				)}],
+				avatar_url: undefined
+			}]
+		}
+	)
+})
+
 test("event2message: quotes have an appropriate amount of whitespace", async t => {
 	t.deepEqual(
 		await eventToMessage({