diff --git a/run_tests.go b/run_tests.go
new file mode 100644
index 000000000..28b1ef389
--- /dev/null
+++ b/run_tests.go
@@ -0,0 +1,162 @@
+// +build ignore
+
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func specialDir(name string) bool {
+	if name == "." {
+		return false
+	}
+
+	base := filepath.Base(name)
+	return base[0] == '_' || base[0] == '.'
+}
+
+func emptyDir(name string) bool {
+	dir, err := os.Open(name)
+	defer dir.Close()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "unable to open directory %v: %v\n", name, err)
+		return true
+	}
+
+	fis, err := dir.Readdir(-1)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Readdirnames(%v): %v\n", name, err)
+		return true
+	}
+
+	for _, fi := range fis {
+		if fi.IsDir() {
+			continue
+		}
+
+		if filepath.Ext(fi.Name()) == ".go" {
+			return false
+		}
+	}
+
+	return true
+}
+
+func forceRelativeDirname(dirname string) string {
+	if dirname == "." {
+		return dirname
+	}
+
+	if strings.HasPrefix(dirname, "./") {
+		return dirname
+	}
+
+	return "./" + dirname
+}
+
+func mergeCoverprofile(file *os.File, out io.Writer) error {
+	_, err := file.Seek(0, 0)
+	if err != nil {
+		return err
+	}
+
+	rd := bufio.NewReader(file)
+	_, err = rd.ReadString('\n')
+	if err == io.EOF {
+		return nil
+	}
+
+	if err != nil {
+		return err
+	}
+
+	_, err = io.Copy(out, rd)
+	if err != nil {
+		return err
+	}
+
+	err = file.Close()
+	if err != nil {
+		return err
+	}
+
+	return err
+}
+
+func testPackage(pkg string, out io.Writer) error {
+	file, err := ioutil.TempFile("", "test-coverage-")
+	defer os.Remove(file.Name())
+	defer file.Close()
+	if err != nil {
+		return err
+	}
+
+	cmd := exec.Command("go", "test",
+		"-cover", "-covermode", "set", "-coverprofile", file.Name(),
+		pkg, "-test.integration")
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+
+	err = cmd.Run()
+	if err != nil {
+		return err
+	}
+
+	return mergeCoverprofile(file, out)
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintln(os.Stderr, "USAGE: run_tests COVERPROFILE [PATHS]")
+		os.Exit(1)
+	}
+
+	target := os.Args[1]
+	dirs := os.Args[2:]
+
+	if len(dirs) == 0 {
+		dirs = append(dirs, ".")
+	}
+
+	file, err := os.Create(target)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "create coverprofile failed: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Fprintln(file, "mode: set")
+
+	for _, dir := range dirs {
+		err := filepath.Walk(dir,
+			func(p string, fi os.FileInfo, e error) error {
+				if e != nil {
+					return e
+				}
+
+				if !fi.IsDir() {
+					return nil
+				}
+
+				if specialDir(p) || emptyDir(p) {
+					return filepath.SkipDir
+				}
+
+				return testPackage(forceRelativeDirname(p), file)
+			})
+
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "walk(%q): %v\n", dir, err)
+		}
+	}
+
+	err = file.Close()
+
+	fmt.Printf("coverprofile: %v\n", file.Name())
+}