1 files changed, 111 insertions, 0 deletions
diff --git a/infra/base-images/base-runner/gocoverage/gocovmerge/gocovmerge.go b/infra/base-images/base-runner/gocoverage/gocovmerge/gocovmerge.go
new file mode 100644
index 000000000..e8099839e
--- /dev/null
+++ b/infra/base-images/base-runner/gocoverage/gocovmerge/gocovmerge.go
@@ -0,0 +1,111 @@
+// gocovmerge takes the results from multiple `go test -coverprofile` runs and
+// merges them into one profile
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"sort"
+
+	"golang.org/x/tools/cover"
+)
+
+func mergeProfiles(p *cover.Profile, merge *cover.Profile) {
+	if p.Mode != merge.Mode {
+		log.Fatalf("cannot merge profiles with different modes")
+	}
+	// Since the blocks are sorted, we can keep track of where the last block
+	// was inserted and only look at the blocks after that as targets for merge
+	startIndex := 0
+	for _, b := range merge.Blocks {
+		startIndex = mergeProfileBlock(p, b, startIndex)
+	}
+}
+
+func mergeProfileBlock(p *cover.Profile, pb cover.ProfileBlock, startIndex int) int {
+	sortFunc := func(i int) bool {
+		pi := p.Blocks[i+startIndex]
+		return pi.StartLine >= pb.StartLine && (pi.StartLine != pb.StartLine || pi.StartCol >= pb.StartCol)
+	}
+
+	i := 0
+	if sortFunc(i) != true {
+		i = sort.Search(len(p.Blocks)-startIndex, sortFunc)
+	}
+	i += startIndex
+	if i < len(p.Blocks) && p.Blocks[i].StartLine == pb.StartLine && p.Blocks[i].StartCol == pb.StartCol {
+		if p.Blocks[i].EndLine != pb.EndLine || p.Blocks[i].EndCol != pb.EndCol {
+			log.Fatalf("OVERLAP MERGE: %v %v %v", p.FileName, p.Blocks[i], pb)
+		}
+		switch p.Mode {
+		case "set":
+			p.Blocks[i].Count |= pb.Count
+		case "count", "atomic":
+			p.Blocks[i].Count += pb.Count
+		default:
+			log.Fatalf("unsupported covermode: '%s'", p.Mode)
+		}
+	} else {
+		if i > 0 {
+			pa := p.Blocks[i-1]
+			if pa.EndLine >= pb.EndLine && (pa.EndLine != pb.EndLine || pa.EndCol > pb.EndCol) {
+				log.Fatalf("OVERLAP BEFORE: %v %v %v", p.FileName, pa, pb)
+			}
+		}
+		if i < len(p.Blocks)-1 {
+			pa := p.Blocks[i+1]
+			if pa.StartLine <= pb.StartLine && (pa.StartLine != pb.StartLine || pa.StartCol < pb.StartCol) {
+				log.Fatalf("OVERLAP AFTER: %v %v %v", p.FileName, pa, pb)
+			}
+		}
+		p.Blocks = append(p.Blocks, cover.ProfileBlock{})
+		copy(p.Blocks[i+1:], p.Blocks[i:])
+		p.Blocks[i] = pb
+	}
+	return i + 1
+}
+
+func addProfile(profiles []*cover.Profile, p *cover.Profile) []*cover.Profile {
+	i := sort.Search(len(profiles), func(i int) bool { return profiles[i].FileName >= p.FileName })
+	if i < len(profiles) && profiles[i].FileName == p.FileName {
+		mergeProfiles(profiles[i], p)
+	} else {
+		profiles = append(profiles, nil)
+		copy(profiles[i+1:], profiles[i:])
+		profiles[i] = p
+	}
+	return profiles
+}
+
+func dumpProfiles(profiles []*cover.Profile, out io.Writer) {
+	if len(profiles) == 0 {
+		return
+	}
+	fmt.Fprintf(out, "mode: %s\n", profiles[0].Mode)
+	for _, p := range profiles {
+		for _, b := range p.Blocks {
+			fmt.Fprintf(out, "%s:%d.%d,%d.%d %d %d\n", p.FileName, b.StartLine, b.StartCol, b.EndLine, b.EndCol, b.NumStmt, b.Count)
+		}
+	}
+}
+
+func main() {
+	flag.Parse()
+
+	var merged []*cover.Profile
+
+	for _, file := range flag.Args() {
+		profiles, err := cover.ParseProfiles(file)
+		if err != nil {
+			log.Fatalf("failed to parse profiles: %v", err)
+		}
+		for _, p := range profiles {
+			merged = addProfile(merged, p)
+		}
+	}
+
+	dumpProfiles(merged, os.Stdout)
+}