Generated agent code broken in Node.js

[Dan Steren]

Describe the bug

Node.js requires a host to be specified when creating an actor using the createActor method in the generated agent. However, the code generated by dfx generate doesn't specify a host and therefore breaks as soon as it is imported.

To Reproduce

Steps to reproduce the behavior:

1. Create a simple canister in the language of your choice

2. Generate an agent by running dfx generate. This will generate among other things an index.js file containing the line export const my_canister_name = createActor(canisterId);

3. Use the generated agent in a simple node.js file. For example:

   import { createActor } from "../dfx_generated";
   
   console.log("We break before we even get here.");
   
   const hello_world_canister = createActor("rrkah-fqaaa-aaaaa-aaaaq-cai", {
     agentOptions: {
       host: "http://127.0.0.1:8000",
     },
   });

4. Run the script with node

5. Note that this results in the following error:

   hello_world/node_modules/@dfinity/agent/lib/cjs/agent/http/index.js:141
                   throw new Error('Must specify a host to connect to.');
                         ^
   Error: Must specify a host to connect to.
       at new HttpAgent (hello_world/node_modules/@dfinity/agent/lib/cjs/agent/http/index.js:141:23)
   

Expected behavior

I should be able to import the createActor statement, or the actor directly without everything breaking.

Desktop (please complete the following information):

• Node v18.1.0
• dfx v0.11.0
• JS Agent v0.11.1

Additional context

There is an open forum post with additional details. See https://forum.dfinity.org/t/generated-declarations-in-node-js-environment-break/12686

[Dan Steren]

As a workaround you can manually comment out the last line in the generated index.js, however this is just a bandaid solution.

[Dan Steren]

Also, this is closely related to dfinity/sdk#2240.

[Kai Peacock]

This has been resolved by -dfinity/sdk@32c168e

To use the feature in your code, add the setting of

canister -> declarations -> "node_compatibility": true