1 files changed, 56 insertions, 0 deletions
diff --git a/golangflag.go b/golangflag.go
index d3dd72b..e62eab5 100644
--- a/golangflag.go
+++ b/golangflag.go
@@ -8,8 +8,18 @@ import (
 	goflag "flag"
 	"reflect"
 	"strings"
+	"time"
 )
 
+// go test flags prefixes
+func isGotestFlag(flag string) bool {
+	return strings.HasPrefix(flag, "-test.")
+}
+
+func isGotestShorthandFlag(flag string) bool {
+	return strings.HasPrefix(flag, "test.")
+}
+
 // flagValueWrapper implements pflag.Value around a flag.Value.  The main
 // difference here is the addition of the Type method that returns a string
 // name of the type.  As this is generally unknown, we approximate that with
@@ -103,3 +113,49 @@ func (f *FlagSet) AddGoFlagSet(newSet *goflag.FlagSet) {
 	}
 	f.addedGoFlagSets = append(f.addedGoFlagSets, newSet)
 }
+
+// CopyToGoFlagSet will add all current flags to the given Go flag set.
+// Deprecation remarks get copied into the usage description.
+// Whenever possible, a flag gets added for which Go flags shows
+// a proper type in the help message.
+func (f *FlagSet) CopyToGoFlagSet(newSet *goflag.FlagSet) {
+	f.VisitAll(func(flag *Flag) {
+		usage := flag.Usage
+		if flag.Deprecated != "" {
+			usage += " (DEPRECATED: " + flag.Deprecated + ")"
+		}
+
+		switch value := flag.Value.(type) {
+		case *stringValue:
+			newSet.StringVar((*string)(value), flag.Name, flag.DefValue, usage)
+		case *intValue:
+			newSet.IntVar((*int)(value), flag.Name, *(*int)(value), usage)
+		case *int64Value:
+			newSet.Int64Var((*int64)(value), flag.Name, *(*int64)(value), usage)
+		case *uintValue:
+			newSet.UintVar((*uint)(value), flag.Name, *(*uint)(value), usage)
+		case *uint64Value:
+			newSet.Uint64Var((*uint64)(value), flag.Name, *(*uint64)(value), usage)
+		case *durationValue:
+			newSet.DurationVar((*time.Duration)(value), flag.Name, *(*time.Duration)(value), usage)
+		case *float64Value:
+			newSet.Float64Var((*float64)(value), flag.Name, *(*float64)(value), usage)
+		default:
+			newSet.Var(flag.Value, flag.Name, usage)
+		}
+	})
+}
+
+// ParseSkippedFlags explicitly Parses go test flags (i.e. the one starting with '-test.') with goflag.Parse(),
+// since by default those are skipped by pflag.Parse().
+// Typical usage example: `ParseGoTestFlags(os.Args[1:], goflag.CommandLine)`
+func ParseSkippedFlags(osArgs []string, goFlagSet *goflag.FlagSet) error {
+	var skippedFlags []string
+	for _, f := range osArgs {
+		if isGotestFlag(f) {
+			skippedFlags = append(skippedFlags, f)
+		}
+	}
+	return goFlagSet.Parse(skippedFlags)
+}
+