Report OpenAPI spec version and last-check date in --version

[ndenny]

Summary

apimetrics --version now reports the OpenAPI document version (info.version) and the date/time the spec was last fetched from the server, to aid customer support and debugging:

apimetrics version <cli-version>
API spec version: <info.version>
Spec last updated:  <date/time>

Background

The CLI already auto-refreshes the cached OpenAPI spec on a 24-hour TTL (cacheAPI in cli/api.go) — that cadence is unchanged here. The value added is visibility: previously the spec's own version was parsed by libopenapi and then discarded, and there was no way to see when the spec was last refreshed.

Changes

• cli/api.go — Add SpecVersion to the cached API struct (CBOR-persisted), carry it through Merge, and record a <name>.checked timestamp in cacheAPI. Add versionExtraInfo() which reads the loaded API or falls back to the on-disk .cbor cache.
• openapi/openapi.go — Capture model.Info.Version into the built cli.API.
• cli/cli.go — Register a versionExtra template func + custom cobra version template, and make --version skip the network load (reads cached state from disk).
• openapi/testdata/*/output.yaml — Fixtures updated to include spec_version.

Resilience

--version is used precisely when things are broken, so it must not depend on the network. It now reads the cached spec state from disk and skips the load entirely — no network call, no auth prompt, no panic when offline. Verified:

Scenario	Result
Cold cache + offline	unknown / never, clean exit
Warm cache, online	spec version + timestamp, no network call
Warm cache, offline	identical — reads from disk

After a binary upgrade, existing caches repopulate automatically (a CLI version change already invalidates the cache).

Testing

• go test ./... — all pass
• go vet ./... — clean
• Manual verification of the four scenarios above

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR enhances apimetrics --version output to include the cached OpenAPI document’s info.version plus a “last checked” timestamp, while ensuring --version avoids any network/API loading (so it remains usable when offline).

Changes:

• Persist OpenAPI info.version into the cached cli.API model (SpecVersion) and expose it via the Cobra version template.
• Record a per-API “checked” timestamp when the API spec cache is written, and display it in --version.
• Update OpenAPI test fixtures to include spec_version in expected YAML output.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
cli/api.go	Adds SpecVersion to cached API state, records <name>.checked, and implements versionExtraInfo() to read cached spec version + timestamp.
cli/cli.go	Customizes Cobra version template and skips network loading when --version is requested.
openapi/openapi.go	Captures model.Info.Version into cli.API.SpecVersion during OpenAPI load.
openapi/testdata/request/output.yaml	Updates expected fixture output to include spec_version.
openapi/testdata/petstore/output.yaml	Updates expected fixture output to include spec_version.
openapi/testdata/long_example/output.yaml	Updates expected fixture output to include spec_version.
openapi/testdata/group-resp/output.yaml	Updates expected fixture output to include spec_version.
openapi/testdata/extensions/output.yaml	Updates expected fixture output to include spec_version.
openapi/testdata/auto_config/output.yaml	Updates expected fixture output to include spec_version.

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[ndenny]

Thanks — both points addressed in 38e4ca3.

versionExtraInfo now gates the on-disk cache read on cached.CLIVersion == Root.Version, mirroring the validity check in Load, so after a binary upgrade --version reports unknown / never rather than a stale spec version/timestamp that the CLI would refetch anyway. The <name>.checked lookup (and the whole cache read) is now also skipped when api-name is empty. Added TestVersionExtraInfo covering the no-cache, valid-cache, and stale-cache (mismatched CLIVersion) paths.

[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 2 comments.