Serve Javascript and source map files locally using Fiddler - part 1

One of the major downsides of developing on Dynamics 365 is that the feedback loop can be pretty long.

Say if we wanted to test a change to an existing Javascript library this is what we would need to do:

1. Make code changes in Visual Studio
2. Upload to Dynamics Server
3. Publish
4. Test

2 and 3 can be time consuming, specially on slow networks or heavily used servers, however there is another way, enter Fiddler.

Fiddler is a Web debugging Proxy that can be used to serve files.

In this example, I have create an extremely simple webresource that contains a single function that provides an annoying greeting every time a account record is opened.

Dynamics solution can be found here and script (in typescript) can be found here (ignore the method name for now)

We can now use Fiddler to serve the files from disk

1. Launch Fiddler
2. Select AutoResponder Tab
3. Create AutoResponder Rules as shown

I've create a single rule for each file

account.js
account.js.map
account.ts

This will allow us to debug our typescript code

Note that once the library has been registered with the form, it's possible to add methods on the source code without uploading them to the server as long as you serve them from Fiddler.

Let's say we wanted a function called  setCreditLimit, which sets the credit limit of the account to say $10000, we could do the following in Visual Studio and register the appropriate handler in the form without having to actually upload the changed file.

If we are doing piecemeal changes like this the effect is not great as we still need to publish the form, but you could register all the events needed and then work at your leisure from Visual Studio.

Having to add rules can get a little bit tedious so in another post we will showcase a different way that will allow to set up a single rule


Don't Forget to upload the web resources once you've finished.