feat: use default params if not provided (#6701)

packages/backend/server/src/plugins/copilot/prompt.ts

@@ -1,4 +1,4 @@
-import { Injectable } from '@nestjs/common';
+import { Injectable, Logger } from '@nestjs/common';
 import { AiPrompt, PrismaClient } from '@prisma/client';
 import Mustache from 'mustache';
 import { Tiktoken } from 'tiktoken';
@@ -26,6 +26,7 @@ function extractMustacheParams(template: string) {
 }
 
 export class ChatPrompt {
+  private readonly logger = new Logger(ChatPrompt.name);
   public readonly encoder?: Tiktoken;
   private readonly promptTokenSize: number;
   private readonly templateParamKeys: string[] = [];
@@ -88,7 +89,7 @@ export class ChatPrompt {
     return this.encoder?.encode_ordinary(message).length || 0;
   }
 
-  private checkParams(params: PromptParams) {
+  private checkParams(params: PromptParams, sessionId?: string) {
     const selfParams = this.templateParams;
     for (const key of Object.keys(selfParams)) {
       const options = selfParams[key];
@@ -97,7 +98,20 @@ export class ChatPrompt {
         typeof income !== 'string' ||
         (Array.isArray(options) && !options.includes(income))
       ) {
-        throw new Error(`Invalid param: ${key}`);
+        if (sessionId) {
+          const prefix = income
+            ? `Invalid param value: ${key}=${income}`
+            : `Missing param value: ${key}`;
+          this.logger.warn(
+            `${prefix} in session ${sessionId}, use default options: ${options[0]}`
+          );
+        }
+        if (Array.isArray(options)) {
+          // use the first option if income is not in options
+          params[key] = options[0];
+        } else {
+          params[key] = options;
+        }
       }
     }
   }
@@ -107,8 +121,8 @@ export class ChatPrompt {
    * @param params record of params, e.g. { name: 'Alice' }
    * @returns e.g. [{ role: 'system', content: 'Hello, {{name}}' }] => [{ role: 'system', content: 'Hello, Alice' }]
    */
-  finish(params: PromptParams): PromptMessage[] {
-    this.checkParams(params);
+  finish(params: PromptParams, sessionId?: string): PromptMessage[] {
+    this.checkParams(params, sessionId);
     return this.messages.map(({ content, params: _, ...rest }) => ({
       ...rest,
       params,

packages/backend/server/src/plugins/copilot/session.ts

@@ -112,7 +112,8 @@ export class ChatSession implements AsyncDisposable {
     const messages = this.takeMessages();
     return [
       ...this.state.prompt.finish(
-        Object.keys(params).length ? params : messages[0]?.params || {}
+        Object.keys(params).length ? params : messages[0]?.params || {},
+        this.config.sessionId
       ),
       ...messages.filter(m => m.content || m.attachments?.length),
     ];
@@ -354,7 +355,7 @@ export class ChatSessionService {
                 // render system prompt
                 const preload = withPrompt
                   ? prompt
-                      .finish(ret.data[0]?.params || {})
+                      .finish(ret.data[0]?.params || {}, id)
                       .filter(({ role }) => role !== 'system')
                   : [];
 

packages/backend/server/tests/copilot.spec.ts

@@ -105,9 +105,14 @@ test('should be able to render prompt', async t => {
     'should have param keys'
   );
   t.deepEqual(testPrompt?.params, msg.params, 'should have params');
-  t.throws(() => testPrompt?.finish({ src_language: 'abc' }), {
-    instanceOf: Error,
-  });
+  // will use first option if a params not provided
+  t.deepEqual(testPrompt?.finish({ src_language: 'abc' }), [
+    {
+      content: 'translate eng to chs: ',
+      params: { dest_language: 'chs', src_language: 'eng' },
+      role: 'system',
+    },
+  ]);
 });
 
 test('should be able to render listed prompt', async t => {