How to debug the sourceCode

i follow the document,but i have some problems. to rebuild packages\engine\Source\Core\Ion.js,the defaultAccessToken is unavaiable,i edit the token,and run npm run build; and npm run build-watch,but none of them can rebuild the Ion.js

2.when i make change in Apps\Sandcastle\gallery\3D Tiles Adjust Height.html it can not apply on [http://localhost:8080/Apps/Sandcastle/index.html?src=3D Tiles Adjust Height.html&label=3D Tiles]

more information is :
1.the sourceCode version i clone now is 1.106,the another version is work when i make the change.
2.the Apps\Sandcastle\index.html can apply immdediately in 1.106

3. when i visit [http://localhost:8080/Apps/Sandcastle/index.html?src=3D%20Tiles%20Adjust%20Height.html&label=3D%20Tiles]
i don’t know wheter is a problem with accesToken

Hi there. It looks like you are trying to update the access token.

Can you explain why you need to edit the Source code rather than set Cesium.Ion.defaultAccessToken from within your application?

Thank you fro your reply.Because i want to change one place,work on the whole program(include the whole sandcatle),the rebuild can make in 0.91.
In you describe, it seems that you hava a better way to work in the whole program,can you show me the way.

@chen21439 I’m not sure I understand.

Are you looking to create an application using CesiumJS? Or, are you looking to change the CesiumJS source code?

no,i just want to change the default access token,so i needn’t to change them in each sandcastle example

i notice that compare to 0.93,high version cesium source code build engine in another package

more work i do in 106 is and none of them work

1.i run npm run build in packages/engine and replace the node_modules@cesium\engine\Build\workers by the output make in packages\engine\Build\workers
2.i modify the token in node_modules@cesium\engine\Source\Core and restart the server

also,for eaxmple,if i want to debug Transform.js and it won’t effect in sandcastle,can you add some script to do make debug more easy like 0.93 @Gabby_Getz