Add default token_type_ids for multilingual-e5-* models (#403)

* Fix #267 & #324

Add default token_type_ids. Fix for multilingual-e5-* family.

* Add add_token_types import

* export `add_token_types`

* Improvements

---------

Co-authored-by: Joshua Lochner <[email protected]>

Author: do-me

src/models.js

@@ -42,6 +42,10 @@ import {
     AutoConfig,
 } from './configs.js';
 
+import {
+    add_token_types,
+} from './tokenizers.js';
+
 import {
     Callable,
     isIntegralNumber,
@@ -488,10 +492,15 @@ function seq2seqUpdatebeam(beam, newTokenId) {
  * @private
  */
 async function encoderForward(self, model_inputs) {
-    let encoderFeeds = {};
-    for (let key of self.session.inputNames) {
+    const encoderFeeds = Object.create(null);
+    for (const key of self.session.inputNames) {
         encoderFeeds[key] = model_inputs[key];
     }
+    if (self.session.inputNames.includes('token_type_ids') && !encoderFeeds.token_type_ids) {
+        // Assign default `token_type_ids` to the `encoderFeeds` if the model expects it,
+        // but they weren't created by the tokenizer.
+        add_token_types(encoderFeeds);
+    }
     return await sessionRun(self.session, encoderFeeds);
 }
 

src/tokenizers.js

@@ -2578,7 +2578,7 @@ export class PreTrainedTokenizer extends Callable {
 * @param {Object} inputs An object containing the input ids and attention mask.
 * @returns {Object} The prepared inputs object.
 */
-function add_token_types(inputs) {
+export function add_token_types(inputs) {
     // TODO ensure correctness when token pair is present
     if (inputs.input_ids instanceof Tensor) {
         inputs.token_type_ids = new Tensor(