4.39.0

* Added: Option to change the size of Message Hover actions.
* Added: New chat action appearance type "Emote" that makes it easy to use an emote image for an action.
* Changed: Do not show the "Pin" action on messages with no message body.
* Changed: Use Twitch's API for embeds/tooltips of Twitch URLs. This now makes use of clip embed data being sent via PubSub, notably.
* Fixed: Multiple emotes with the same name being listed in tab-completion.

* Experiment: There's a new chat line render method available. This is not currently enabled for any users, but it will be enabled after more internal testing. The new method is not necessarily faster, though it should not be slower. The main purpose of the rewrite is code de-duplication and making the renderer easier to maintain.
* API Added: `chat.addLinkProvider(provider);` to register a handler for link data.
* API Fixed: Do not allow duplicate registration of tokenizers or rich embed handlers for chat.

src/modules/chat/index.js

@@ -20,6 +20,7 @@ import Room from './room';
 import User from './user';
 import * as TOKENIZERS from './tokenizers';
 import * as RICH_PROVIDERS from './rich_providers';
+import * as LINK_PROVIDERS from './link_providers';
 
 import Actions from './actions';
 import { getFontsList } from 'src/utilities/fonts';
@@ -99,6 +100,9 @@ export default class Chat extends Module {
 		this.rich_providers = {};
 		this.__rich_providers = [];
 
+		this.link_providers = {};
+		this.__link_providers = [];
+
 		this._hl_reasons = {};
 		this.addHighlightReason('mention', 'Mentioned');
 		this.addHighlightReason('user', 'Highlight User');
@@ -1241,6 +1245,8 @@ export default class Chat extends Module {
 	onEnable() {
 		this.socket = this.resolve('socket');
 
+		this.on('site.subpump:pubsub-message', this.onPubSub, this);
+
 		if ( this.context.get('chat.filtering.color-mentions') )
 			this.createColorCache().then(() => this.emit(':update-line-tokens'));
 
@@ -1251,6 +1257,47 @@ export default class Chat extends Module {
 		for(const key in RICH_PROVIDERS)
 			if ( has(RICH_PROVIDERS, key) )
 				this.addRichProvider(RICH_PROVIDERS[key]);
+
+		for(const key in LINK_PROVIDERS)
+			if ( has(LINK_PROVIDERS, key) )
+				this.addLinkProvider(LINK_PROVIDERS[key]);
+	}
+
+
+	onPubSub(event) {
+		if ( event.prefix === 'stream-chat-room-v1' && event.message.type === 'chat_rich_embed' ) {
+			const data = event.message.data,
+				url = data.request_url,
+
+				providers = this.__link_providers;
+
+			// Don't re-cache.
+			if ( this._link_info[url] )
+				return;
+
+			for(const provider of providers) {
+				const match = provider.test.call(this, url);
+				if ( match ) {
+					const processed = provider.receive ? provider.receive.call(this, match, data) : data;
+					let result = provider.process.call(this, match, processed);
+
+					if ( !(result instanceof Promise) )
+						result = Promise.resolve(result);
+
+					result.then(value => {
+						// If something is already running, don't override it.
+						let info = this._link_info[url];
+						if ( info )
+							return;
+
+						// Save the value.
+						this._link_info[url] = [true, Date.now() + 120000, value];
+					});
+
+					return;
+				}
+			}
+		}
 	}
 
 
@@ -1855,6 +1902,11 @@ export default class Chat extends Module {
 
 	addTokenizer(tokenizer) {
 		const type = tokenizer.type;
+		if ( has(this.tokenizers, type) ) {
+			this.log.warn(`Tried adding tokenizer of type '${type}' when one was already present.`);
+			return;
+		}
+
 		this.tokenizers[type] = tokenizer;
 		if ( tokenizer.priority == null )
 			tokenizer.priority = 0;
@@ -1894,8 +1946,48 @@ export default class Chat extends Module {
 		return tokenizer;
 	}
 
+	addLinkProvider(provider) {
+		const type = provider.type;
+		if ( has(this.link_providers, type) ) {
+			this.log.warn(`Tried adding link provider of type '${type}' when one was already present.`);
+			return;
+		}
+
+		this.link_providers[type] = provider;
+		if ( provider.priority == null )
+			provider.priority = 0;
+
+		this.__link_providers.push(provider);
+		this.__link_providers.sort((a,b) => {
+			if ( a.priority > b.priority ) return -1;
+			if ( a.priority < b.priority ) return 1;
+			return a.type < b.type;
+		});
+	}
+
+	removeLinkProvider(provider) {
+		let type;
+		if ( typeof provider === 'string' ) type = provider;
+		else type = provider.type;
+
+		provider = this.link_providers[type];
+		if ( ! provider )
+			return null;
+
+		const idx = this.__link_providers.indexOf(provider);
+		if ( idx !== -1 )
+			this.__link_providers.splice(idx, 1);
+
+		return provider;
+	}
+
 	addRichProvider(provider) {
 		const type = provider.type;
+		if ( has(this.rich_providers, type) ) {
+			this.log.warn(`Tried adding rich provider of type '${type}' when one was already present.`);
+			return;
+		}
+
 		this.rich_providers[type] = provider;
 		if ( provider.priority == null )
 			provider.priority = 0;
@@ -2108,6 +2200,17 @@ export default class Chat extends Module {
 						cbs[success ? 0 : 1](data);
 			}
 
+			// Try using a link provider.
+			for(const lp of this.__link_providers) {
+				const match = lp.test.call(this, url);
+				if ( match ) {
+					timeout(lp.process.call(this, match), 15000)
+						.then(data => handle(true, data))
+						.catch(err => handle(false, err));
+					return;
+				}
+			}
+
 			let provider = this.settings.get('debug.link-resolver.source');
 			if ( provider == null )
 				provider = this.experiments.getAssignment('api_links') ? 'test' : 'socket';