Fix Mistral's Chat Completion moment

src/prompt-converters.js

@@ -354,6 +354,71 @@ function convertGooglePrompt(messages, model, useSysPrompt = false, charName = '
     return { contents: contents, system_instruction: system_instruction };
 }
 
+/**
+ * Convert a prompt from the ChatML objects to the format used by MistralAI.
+ * @param {object[]} messages Array of messages
+ * @param {string} model Model name
+ * @param {string} charName Character name
+ * @param {string} userName User name
+ */
+function convertMistralMessages(messages, model, charName = '', userName = '') {
+    if (!Array.isArray(messages)) {
+        return [];
+    }
+
+    //large seems to be throwing a 500 error if we don't make the first message a user role, most likely a bug since the other models won't do this
+    if (model.includes('large')) {
+        messages[0].role = 'user';
+    }
+
+    //must send a user role as last message
+    const lastMsg = messages[messages.length - 1];
+    if (messages.length > 0 && lastMsg && (lastMsg.role === 'system' || lastMsg.role === 'assistant')) {
+        if (lastMsg.role === 'assistant' && lastMsg.name) {
+            lastMsg.content = lastMsg.name + ': ' + lastMsg.content;
+        } else if (lastMsg.role === 'system') {
+            lastMsg.content = '[INST] ' + lastMsg.content + ' [/INST]';
+        }
+        lastMsg.role = 'user';
+    }
+
+    //system prompts can be stacked at the start, but any futher sys prompts after the first user/assistant message will break the model
+    let encounteredNonSystemMessage = false;
+    messages.forEach(msg => {
+        if (msg.role === 'system' && msg.name === 'example_assistant') {
+            if (charName) {
+                msg.content = `${charName}: ${msg.content}`;
+            }
+            delete msg.name;
+        }
+
+        if (msg.role === 'system' && msg.name === 'example_user') {
+            if (userName) {
+                msg.content = `${userName}: ${msg.content}`;
+            }
+            delete msg.name;
+        }
+
+        if (msg.name) {
+            msg.content = `${msg.name}: ${msg.content}`;
+            delete msg.name;
+        }
+
+        if ((msg.role === 'user' || msg.role === 'assistant') && !encounteredNonSystemMessage) {
+            encounteredNonSystemMessage = true;
+        }
+
+        if (encounteredNonSystemMessage && msg.role === 'system') {
+            msg.role = 'user';
+            //unsure if the instruct version is what they've deployed on their endpoints and if this will make a difference or not.
+            //it should be better than just sending the message as a user role without context though
+            msg.content = '[INST] ' + msg.content + ' [/INST]';
+        }
+    });
+
+    return messages;
+}
+
 /**
  * Convert a prompt from the ChatML objects to the format used by Text Completion API.
  * @param {object[]} messages Array of messages
@@ -385,4 +450,5 @@ module.exports = {
     convertGooglePrompt,
     convertTextCompletionPrompt,
     convertCohereMessages,
+    convertMistralMessages,
 };