Add test sub command

Allows compiling a test binary and debugging it.

README.md

@@ -53,6 +53,12 @@ The debugger can be launched in three ways:
 	$ dlv run
 	```
 
+* Compile test binary, run and attach:
+
+	```
+	$ dlv test
+	```
+
 * Provide the name of the program you want to debug, and the debugger will launch it for you.
 
 	```

client/cli/cli.go

@@ -6,8 +6,9 @@ import (
 	"os"
 	"os/exec"
 	"os/signal"
-	"strings"
+	"path/filepath"
 	"strconv"
+	"strings"
 
 	sys "golang.org/x/sys/unix"
 
@@ -41,6 +42,24 @@ func Run(args []string) {
 		if err != nil {
 			die(1, "Could not launch program:", err)
 		}
+	case "test":
+		wd, err := os.Getwd()
+		if err != nil {
+			die(1, err)
+		}
+		base := filepath.Base(wd)
+		cmd := exec.Command("go", "test", "-c", "-gcflags", "-N -l")
+		err = cmd.Run()
+		if err != nil {
+			die(1, "Could not compile program:", err)
+		}
+		debugname := "./" + base + ".test"
+		defer os.Remove(debugname)
+
+		dbp, err = proctl.Launch(append([]string{debugname}, args...))
+		if err != nil {
+			die(1, "Could not launch program:", err)
+		}
 	case "attach":
 		pid, err := strconv.Atoi(args[1])
 		if err != nil {

cmd/dlv/main.go

@@ -22,6 +22,7 @@ Invoke with the path to a binary:
 
 or use the following commands:
   run - Build, run, and attach to program
+  test - Build test binary, run and attach to it
   attach - Attach to running process
 `, version)