feat(discord): support <code-block> (#279)

Co-authored-by: Shigma <[email protected]>

adapters/discord/src/message.ts

@@ -1,7 +1,7 @@
 import { Context, Dict, h, MessageEncoder, Schema, Universal } from '@satorijs/core'
 import { DiscordBot } from './bot'
 import { ActionRow, Button, ButtonStyles, Channel, ComponentType, Message } from './types'
-import { decodeMessage, sanitize } from './utils'
+import { decodeMessage, sanitize, sanitizeCode } from './utils'
 
 type RenderMode = 'default' | 'figure'
 
@@ -230,9 +230,13 @@ export class DiscordMessageEncoder<C extends Context = Context> extends MessageE
       await this.render(children)
       this.buffer += '||'
     } else if (type === 'code') {
-      this.buffer += '`'
-      await this.render(children)
-      this.buffer += '`'
+      this.buffer += '``'
+      this.buffer += sanitizeCode(children.toString())
+      this.buffer += '``'
+    } else if (type === 'code-block') {
+      this.buffer += `\`\`\`${attrs.language ?? ''}\n`
+      this.buffer += sanitizeCode(children.toString())
+      this.buffer += '\n```'
     } else if (type === 'a') {
       this.buffer += '['
       await this.render(children)

adapters/discord/src/utils.ts

@@ -10,6 +10,10 @@ export const sanitize = (val: string) =>
     .replace(/@everyone/g, () => '\\@everyone')
     .replace(/@here/g, () => '\\@here')
 
+// discord has no way to escape ` in code/codeblock, so we use zero-width space as a fallback.
+// we don't need or have to do any escape other than ` in code/codeblock.
+export const sanitizeCode = (val: string) => val.replace(/(?<=`)(?=`)/g, '\u200b')
+
 export const decodeUser = (user: Discord.User): Universal.User => ({
   id: user.id,
   name: user.username,