fix(config): keep embedded-constructed structs constructible (un-break coordinode)

[polaz]

Summary

The blanket #[non_exhaustive] (shipped in 2.0.0) broke embedded consumers that build the config programmatically with struct literals, rather than loading YAML. coordinode does exactly this in coordinode-server to inject the runtime upstream port, listen address, and baked-in descriptors:

let config = ProxyConfig {
    upstream: UpstreamConfig { default: grpc_upstream },
    descriptors: vec![DescriptorSource::Embedded { bytes: DESCRIPTOR_BYTES }],
    listen: ListenConfig { http: rest_addr },
    service: ServiceConfig { name: "coordinode".into() },
    ...
};
ProxyServer::from_config(config)

With #[non_exhaustive] on those structs, this stops compiling for any external crate.

Fix: scope non_exhaustive correctly

• Removed from the wiring structs an embedding consumer legitimately builds: ProxyConfig, UpstreamConfig, ListenConfig, ServiceConfig, and the DescriptorSource enum.
• Kept on the 16 leaf auth/shield/oidc/etc. config structs that are deserialized (never hand-built) and that actually churn (these are what tripped cargo-semver-checks).

Principle: #[non_exhaustive] belongs on deserialized-only leaf config, not on the wiring structs consumers construct programmatically.

Dev UX

• Added ProxyConfig::from_yaml_str(&str) so an embedded build can load a baked-in config (include_str!) without touching the filesystem.
• Added tests/embedded.rs — a separate-crate integration test that reproduces coordinode's exact construction (ProxyConfig literal + DescriptorSource::Embedded + ProxyServer). Because it's an external crate, it sees non_exhaustive like a real consumer: if any wiring struct regains it, this test fails to compile and the regression is caught.

Versioning

Removing #[non_exhaustive] is a relaxation (more permissive), so this is a non-breaking patch (2.0.1), not a major bump. cargo-semver-checks is satisfied.

Testing

cargo nextest run --features redis: 121 passed (incl. the 2 new external-crate embedded tests). clippy (all-features) + fmt clean.

Closes #45

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: c2ed3609-1ff5-44da-a06f-430a5cb1906c

📥 Commits

Reviewing files that changed from the base of the PR and between 2535613 and bbc1fef.

📒 Files selected for processing (1)

• tests/embedded.rs

---

📝 Walkthrough

Summary by CodeRabbit

• New Features

  • Added support for constructing proxy configuration from in-memory YAML strings via ProxyConfig::from_yaml_str.

• Tests

  • Added tests covering embedded/in-memory configuration construction and YAML-string parsing to validate ProxyServer::from_config and loaded service.name.

Walkthrough

#[non_exhaustive] is removed from ProxyConfig, UpstreamConfig, ListenConfig, and ServiceConfig. A new public method ProxyConfig::from_yaml_str is added for parsing YAML strings, and from_file is refactored to delegate to it. A new integration test file tests/embedded.rs verifies both programmatic struct construction and YAML string parsing.

Changes

Embedded Config Constructibility

Layer / File(s)	Summary
Remove #[non_exhaustive] and add from_yaml_str src/config.rs	Removes #[non_exhaustive] from ProxyConfig, UpstreamConfig, ListenConfig, and ServiceConfig. Adds from_yaml_str(yaml: &str) -> anyhow::Result<Self> and refactors from_file to delegate to it via read_to_string.
Integration tests for embedded construction and YAML parsing tests/embedded.rs	Adds embedded_config_is_constructible (builds ProxyConfig in code with DescriptorSource::Embedded and calls ProxyServer::from_config) and from_yaml_str_loads_config (parses YAML via from_yaml_str and asserts the service name).

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• structured-world/structured-proxy#44: Added #[non_exhaustive] to the same config structs in src/config.rs that this PR removes it from, making it the direct predecessor change being partially reversed.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly indicates the primary fix: removing non_exhaustive from constructible structs to restore embedded consumer compatibility.
Description check	✅ Passed	The description provides comprehensive context about the breaking change, the fix strategy, dev improvements, and testing rationale.
Linked Issues check	✅ Passed	The changes fully implement the objectives from issue #45: removing non_exhaustive from wiring structs, keeping it on leaf deserialized-only configs, adding from_yaml_str method, and introducing separate-crate integration tests.
Out of Scope Changes check	✅ Passed	All changes are directly aligned with issue #45 requirements: scoped non_exhaustive removal, new from_yaml_str method, and embedded integration tests.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/#45-embedded-constructible

---

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[greptile-apps]

Greptile Summary

Scopes #[non_exhaustive] correctly by removing it from the five "wiring" types (ProxyConfig, UpstreamConfig, ListenConfig, ServiceConfig, DescriptorSource) that embedding consumers construct programmatically, while keeping it on the 16+ leaf auth/shield/oidc structs that are deserialized-only. A new from_yaml_str helper enables include_str!-style embedded configs without filesystem access.

• from_file is refactored to delegate to from_yaml_str; the two are functionally identical, just with the read step moved out.
• tests/embedded.rs is an external-crate integration test that will fail to compile if any wiring struct inadvertently regains #[non_exhaustive], guarding the regression permanently.

Confidence Score: 5/5

Safe to merge — the change relaxes the public API (removes restrictions on struct construction) without altering any runtime behavior.

Removing #[non_exhaustive] from the wiring structs is a purely additive API change. from_file is correctly refactored to delegate to from_yaml_str with identical semantics. The leaf configs that actually churn retain their #[non_exhaustive] guard. The new external-crate test permanently catches any regression where a wiring struct regains the attribute.

No files require special attention.

Important Files Changed

Filename	Overview
src/config.rs	Removes #[non_exhaustive] from five wiring structs/enum, adds from_yaml_str convenience method (and delegates from_file to it). The leaf auth/shield/oidc structs retain #[non_exhaustive]; the refactoring is functionally equivalent to the old from_file body.
tests/embedded.rs	New external-crate integration test that reproduces the coordinode embedding pattern; includes a structural-literal test and a from_yaml_str parse test. Comment on forwarded_headers correctly warns about bypassing serde defaults.

_{Reviews (2): Last reviewed commit: "docs(test): clarify forwarded_headers in..." | Re-trigger Greptile}