From 97f96bd13f342d3e9f55359538cc8ddeeb3928c9 Mon Sep 17 00:00:00 2001
From: Dmitriy Derepko <xepozz@list.ru>
Date: Tue, 4 Aug 2026 12:38:49 +0400
Subject: [PATCH] feat(coverage): dump LCOV after 'wippy test' when
 WIPPY_COVERAGE set
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Calls the go-lua coverage collector's WriteCoverageLCOV/CoverageSummary right
after shutdown.Perform in runWithUseCase — covering both the clean-exit and the
os.Exit(exitCode!=0) paths, so coverage is captured even when tests fail.

Configured via env: WIPPY_COVERAGE (enable, read by go-lua at init),
WIPPY_COVERAGE_FILE (output, default coverage.info), WIPPY_COVERAGE_FILTER
(source-name substring, e.g. 'app.').

Requires the go-lua coverage collector (CoverageEnabled/WriteCoverageLCOV/
CoverageSummary) — not in upstream go-lua v1.5.16. Build with:
  go mod edit -replace github.com/wippyai/go-lua=/path/to/go-lua@feature/coverage-collector
No-op (single bool check) when WIPPY_COVERAGE is unset.
---
 cmd/wippy/cmd/run.go | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/cmd/wippy/cmd/run.go b/cmd/wippy/cmd/run.go
index 78b91e6f8..71fffdb0a 100644
--- a/cmd/wippy/cmd/run.go
+++ b/cmd/wippy/cmd/run.go
@@ -33,6 +33,7 @@ import (
 	"github.com/wippyai/runtime/cmd/internal/shutdown"
 	embedpkg "github.com/wippyai/runtime/service/fs/embed"
 	supervisorpkg "github.com/wippyai/runtime/system/supervisor"
+	lua "github.com/wippyai/go-lua"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 )
@@ -289,6 +290,9 @@ func runWithUseCase(cmd *cobra.Command, args []string, useCase string) error {
 	waitForShutdownSignal(sigChan, logger, nil)
 
 	exitCode := shutdown.Perform(ctx, loader, logger, silentLogs)
+	if lua.CoverageEnabled() {
+		dumpCoverage()
+	}
 	if exitCode != 0 {
 		_ = logger.Sync()
 		os.Exit(exitCode)
@@ -297,6 +301,33 @@ func runWithUseCase(cmd *cobra.Command, args []string, useCase string) error {
 	return nil
 }
 
+// dumpCoverage writes an LCOV tracefile when WIPPY_COVERAGE is set. It runs both
+// on a clean exit (return nil) and before os.Exit on a failing run, so coverage
+// is captured even when tests fail. Configured via env:
+//
+//	WIPPY_COVERAGE_FILE    output path (default: coverage.info)
+//	WIPPY_COVERAGE_FILTER  substring the source name must contain (default: all)
+func dumpCoverage() {
+	prefix := os.Getenv("WIPPY_COVERAGE_FILTER")
+	filter := func(src string) bool {
+		return prefix == "" || strings.Contains(src, prefix)
+	}
+	path := os.Getenv("WIPPY_COVERAGE_FILE")
+	if path == "" {
+		path = "coverage.info"
+	}
+	if err := lua.WriteCoverageLCOV(path, filter); err != nil {
+		fmt.Fprintf(os.Stderr, "coverage: write failed: %v\n", err)
+		return
+	}
+	lf, lh := lua.CoverageSummary(filter)
+	pct := 0.0
+	if lf > 0 {
+		pct = float64(lh) / float64(lf) * 100
+	}
+	fmt.Fprintf(os.Stderr, "coverage: %d/%d lines (%.1f%%) filter=%q -> %s\n", lh, lf, pct, prefix, path)
+}
+
 // loadRuntimeConfig resolves the effective runtime configuration for run-like
 // commands by merging:
 // 1) config file/defaults,