rpc: maximum call stack size exceeded

[vince-fugnitto]

Bug Description:

I noticed when using the vscode-git and vscode-git-base builtins that we get a maximum call stack exceeded error:

Uncaught (in promise) Error: Error during encoding: 'Maximum call stack size exceeded'
    at MsgPackMessageEncoder.encode (rpc-message-encoder.ts:151)
    at MsgPackMessageEncoder.request (rpc-message-encoder.ts:137)
    at RpcProtocol.sendRequest (rpc-protocol.ts:161)
    at proxy-handler.ts:74

The error is thrown when interacting with the inline toolbar item for resources.

Steps to Reproduce:

1. start the application without @theia/git in either the browser or electron
2. comment out the following so yarn download:plugins pulls the builtins

   theia/package.json

   Lines 122 to 123 in 371ab02

   	"vscode.git",
   	"vscode.git-ui",

3. build, download plugins, and start the application
4. open a workspace under git version control
5. make changes
6. attempt to interact with the scm view with the inline toolbar item for the changes

[tsmaeder]

Maybe something like #12172?

[vince-fugnitto]

Maybe something like #12172?

I don't believe so, I believe it has to do with some circular reference. I tried #12172 and could still reproduce the issue.

[marcdumais-work]

update: I traced the warnings below in the dev-tools and do not believe they are obviously related to this ticket. Seems more like they are relatively harmless warnings.

---

Here are vscode.git warning traces, perhaps related to this issue, from the browser console. They are about the extension registering menu items and finding missing sub-menus scm/sourceControl and scm/change/title:

[safisa]

I got these errors too...

[vince-fugnitto]

The issue happens as I've mentioned due to circular reference issues when we attempt to encode, we should do a better job at serializing:

The ScmPluginResource is referencing itself.

[tsmaeder]

@vince-fugnitto I would argue that the problem is that we're trying to send plugin-provided objects over the main/ext interface, when we really should be sending well-known DTO's instead. Is this what's happening? Handling general recursive structures is out of scope for our rpc framework.

[msujew]

@tsmaeder The PluginScmResource actually isn't a plugin provided object, but created on the frontend side:

theia/packages/plugin-ext/src/main/browser/scm-main.ts

Lines 82 to 99 in 60209ec

	export class PluginScmResource implements ScmResource {
	constructor(
	private readonly proxy: ScmExt,
	private readonly sourceControlHandle: number,
	private readonly groupHandle: number,
	readonly handle: number,
	readonly sourceUri: URI,
	readonly group: PluginScmResourceGroup,
	readonly decorations: ScmResourceDecorations,
	readonly contextValue: string | undefined,
	readonly command: ScmCommand | undefined
	) { }
	open(): Promise<void> {
	return this.proxy.$executeResourceCommand(this.sourceControlHandle, this.groupHandle, this.handle);
	}
	}

But you're right anyway, as we need to send a DTO instead.