Increase test coverage from 29.6% to 78.8% (target: 70%)

[Copilot]

Test coverage was at 29.6% with no tests for pkg/k8s and sparse coverage in pkg/api and pkg/cleanup. Brings total coverage to 78.8% by introducing fake Kubernetes client injection and comprehensive test suites across all packages.

Core enabler: fake k8s client injection

pkg/k8s/client.go: changed clientset field from *kubernetes.Clientset to kubernetes.Interface (backward-compatible) and added NewClientFromInterface() constructor — allows tests to inject k8s.io/client-go/kubernetes/fake without hitting a real cluster.

New / expanded test coverage

• pkg/k8s (0% → 80.1%): portToInt32 boundary cases; GetPodStatus for all pod phases including CrashLoopBackOff; CreateSandbox variants (RuntimeClass, ImagePullSecrets, CA cert mount, env vars, all command forms); DeleteSandbox (normal + not-found); WaitForPodReady timeout; DiscoverRuntimeBySessionID/RuntimeID (found, missing, no-label cases)

• pkg/api (27.2% → 84.8%): Full handler lifecycle via fake k8s — StartRuntime, StopRuntime, PauseRuntime, ResumeRuntime success paths; all error/validation branches; LoggingMiddleware in debug mode; rewriteCookiePath and createProxyResponseRewriter edge cases; VSCode proxy routing

• pkg/cleanup (21.0% → 87.7%): Start/Stop with context cancellation; runCleanup with failed-pod and idle-pod cleanup; LastActivityTime vs CreatedAt idle threshold logic

• pkg/types (83.3% → 100%): FlexibleCommand.String() and invalid JSON unmarshal error path

Threshold enforcement

Updated coverage gate from 25% → 70% in both Makefile and .github/workflows/ci.yml.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• runtime-rt-vscode.test.svc.cluster.local
  • Triggering command: /tmp/go-build4041447183/b001/api.test /tmp/go-build4041447183/b001/api.test -test.paniconexit0 -test.gocoverdir=/tmp/go-build4041447183/b001/gocoverdir -test.timeout=10m0s -test.coverprofile=/tmp/go-build4041447183/b001/_cover_.out go1.24.12 -coveragecfg=/tmp/go-build234948492/b001/coveragecfg -c=4 -nolocalimports -importcfg /tmp/go-build234948492/b001/importcfg -pack -o .test -trimpath ux_amd64/compile -p /v1/fake imerchan=1,gotestjsonbuildtext=1-stringintconv ux_amd64/compile (dns block)
  • Triggering command: /tmp/go-build1794031033/b001/api.test /tmp/go-build1794031033/b001/api.test -test.paniconexit0 -test.gocoverdir=/tmp/go-build1794031033/b001/gocoverdir -test.timeout=10m0s -test.coverprofile=/tmp/go-build1794031033/b001/_cover_.out d/rbac/v1/fake/dINVALID,NEW d/rbac/v1/fake/f-j ux_amd64/compileDROP -p github.com/golan-test.paniconexit0 -lang=go1.17 ux_amd64/compile-test.timeout=10m0s -uns�� 48687320/b612/gocoverdir /tmp/go-build1848687320/b028/vet-nolocalimports -data-downloader -c=4 fake -importcfg -data-downloader (dns block)
  • Triggering command: /tmp/go-build185634227/b659/api.test /tmp/go-build185634227/b659/api.test -test.paniconexit0 -test.gocoverdir=/tmp/go-build185634227/b659/gocoverdir -test.timeout=10m0s -test.coverprofile=/tmp/go-build185634227/b659/_cover_.out 8687320/b527/_pkg_.a -trimpath (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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