Flatten DTO option parameters in Go polyglot generator

[davidfowl]

Problem

The Go polyglot generator currently nests an optional DTO parameter inside the generated method-options wrapper when the C# API has an optional parameter named options.

For example, the Foundry hosted-agent API currently generates a Go call shape like:

hostedAgent.AsHostedAgent(project, &aspire.AsHostedAgentOptions{
    Options: &aspire.HostedAgentOptions{
        Description: "Validation hosted agent",
        Cpu: aspire.Float64Ptr(1),
        Memory: aspire.Float64Ptr(2),
    },
})

This is awkward because there are two different options concepts:

• AsHostedAgentOptions: the generated Go wrapper for optional method parameters
• HostedAgentOptions: the DTO that represents the actual API options payload

TypeScript already flattens this scenario into the user-facing DTO shape:

await hostedAgent.asHostedAgent(project, {
    description: "Validation hosted agent",
    cpu: 1,
    memory: 2
});

Expected behavior

The Go generator should apply equivalent flattening for optional DTO parameters so Go callers do not have to write Options: &HostedAgentOptions{ ... } when the optional parameter is itself the exported DTO/options payload.

Notes

This came up while updating the Foundry hosted-agent polyglot fixtures in PR #17545. That PR keeps the generated Go shape as-is and should not take the generator fix.

[joperezr]

🤖 Aspire triage pass — 2026-05-29 16:20 UTC

Area: area-polyglot
Kind: feature-request (generator enhancement)
Repro: yes-minimal — Go vs. TypeScript shape comparison in issue body (lines ~10–28)
Affected version(s): 13.4 (current Go polyglot generator); behavior already correct in the TypeScript generator
Severity: S3 — ergonomic gap with a clear workaround (callers can wrap in the outer …Options struct as generated today)

Urgency: 🟡 vNext — recommend milestone 13.5
Reason: Generator polish that does not block 13.4. The reporter explicitly notes that the related 13.4 PR (#17545) keeps current shape and should not take the fix, so this is intentionally deferred. Doesn't clear the snapped-13.4 bar, but is concrete enough that it shouldn't sit in raw backlog.

Suggested owner(s): @sebastienros (primary), backup @IEvangelist
Evidence:

• @sebastienros recently merged area-polyglot PRs Expand TypeScript brownfield workspace validation #17510, Unify ATS withReference exports #15238 and was assignee-of-record on closed-completed polyglot issues Polyglot withHttpEndpointCallback / withEndpointCallback deadlocks when callback body performs nested RPC mutation #17391, aspire update for TypeScript AppHost fails with "No code generator found for language: TypeScript" when CLI is older than target package version; leaves project in broken state #17077, Update API docs content for polyglot TypeScript support #17068, Add TypeScript parity for aspire.dev AppHost snippets #17047, Generate TypeScript API documentation from C# XML docs #17044, Clean up public docs for TypeScript AppHost GA #17043, Add TypeScript generated API compatibility validation #17041, Validate shipped CLI and bundle layout for TypeScript AppHosts #17040, Add stable TypeScript AppHost publish E2E coverage #17038, Expand TypeScript coverage for JavaScript hosting APIs #17037, Expand TypeScript brownfield and workspace validation #17036, Add end-to-end package-manager coverage for TypeScript AppHosts #17033, Add Node LTS CI matrix for TypeScript AppHosts #17030 (last 30–90d)
• @IEvangelist recently merged Fix TypeScript AppHost deadlock for async callbacks #17508 and closed-completed TypeScript AppHost: async configure callback deadlocks aspire start when stored inside lazy IOptions.Configure (RunAsync runs on NonConcurrentSynchronizationContext) #17487, Add TypeScript AppHost scaffold lint regression coverage #17035, Validate aspire doctor diagnostics for TypeScript AppHost package managers #17032, Document TypeScript AppHost package-manager support policy #17031 in area-polyglot
• Issue author @davidfowl is excluded from owner candidates per triage rules
• No CODEOWNERS file paths are cited in the issue body

Confidence: medium — area is unambiguous (area-polyglot already applied by reporter); owner inference is strong for the TypeScript generator surface but weaker for the Go generator path specifically, so a human should confirm Go-generator ownership.
Needs human?: no

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