Specify number of splits to make for command arguments

lib/common.go

@@ -99,24 +99,43 @@ func ContainsCommand(s, prefix, cmd string) bool {
 	return false
 }
 
-func SplitCommandAndArg(s, prefix string) (cmd string, args []string) {
+func SplitCommandAndArg(s, prefix string) (cmd string, arg string) {
 	s = strings.TrimSpace(s)
 
 	if !strings.HasPrefix(s, prefix) {
 		return
 	}
 
-	x := strings.Split(s, " ")
+	// remove the command prefix
+	s = s[len(prefix):]
 
-	if len(x) > 1 {
-		args = x[1:]
-	}
+	// multiple assignment trick
+	cmd, arg = func() (string, string) {
+		x := strings.SplitN(s, " ", 2)
+		if len(x) > 1 {
+			return x[0], x[1]
+		}
+		return x[0], ""
+	}()
 
-	cmd = x[0]
-
-	if strings.Index(s, prefix) == 0 {
-		cmd = cmd[len(prefix):]
-	}
-
-	return cmd, args
+	return cmd, arg
+}
+
+func SplitCommandAndArgs(s, prefix string, n int) (cmd string, args []string) {
+	cmd, arg := SplitCommandAndArg(s, prefix)
+
+	if n == 0 {
+		return cmd, strings.Split(arg, " ")
+	}
+
+	return cmd, strings.SplitN(arg, " ", n)
+}
+
+func SplitArgs(s string, n int) (args []string) {
+	if n > 0 {
+		args = strings.SplitN(s, " ", n)
+	} else {
+		args = strings.Split(s, " ")
+	}
+	return
 }

lib/common_test.go

@@ -57,20 +57,44 @@ func TestHasCommandCommand(t *testing.T) {
 	}
 }
 
-func TestSplitComandAndArgs(t *testing.T) {
+func TestSplitCommandAndArg(t *testing.T) {
 	tables := []struct {
-		s        string
-		prefix   string
-		wantCmd  string
-		wantArgs []string
+		s       string
+		prefix  string
+		wantCmd string
+		wantArg string
 	}{
-		{"!command x y", "!", "command", []string{"x", "y"}},
-		{"!command", "!", "command", []string(nil)},
-		{"hey man", "!", "", []string(nil)},
+		{"!command x y", "!", "command", "x y"},
+		{"!command", "!", "command", ""},
+		{"hey man", "!", "", ""},
 	}
 
 	for _, table := range tables {
-		gotCmd, gotArgs := SplitCommandAndArgs(table.s, table.prefix)
+		gotCmd, gotArg := SplitCommandAndArg(table.s, table.prefix)
+		if gotCmd != table.wantCmd {
+			t.Errorf("got: %s, want: %s", gotCmd, table.wantCmd)
+		}
+		if gotArg != table.wantArg {
+			t.Errorf("got: %+v, want: %+v", gotArg, table.wantArg)
+		}
+	}
+}
+
+func TestSplitCommandAndArgs(t *testing.T) {
+	tables := []struct {
+		s        string
+		prefix   string
+		n        int
+		wantCmd  string
+		wantArgs []string
+	}{
+		{"!command x y", "!", 2, "command", []string{"x", "y"}},
+		{"!command x y z", "!", 2, "command", []string{"x", "y z"}},
+		{"!command", "!", 1, "command", []string{""}},
+		{"hey man", "!", 1, "", []string{""}},
+	}
+	for _, table := range tables {
+		gotCmd, gotArgs := SplitCommandAndArgs(table.s, table.prefix, table.n)
 		if gotCmd != table.wantCmd {
 			t.Errorf("got: %s, want: %s", gotCmd, table.wantCmd)
 		}
@@ -79,3 +103,22 @@ func TestSplitComandAndArgs(t *testing.T) {
 		}
 	}
 }
+
+func TestSplitArgs(t *testing.T) {
+	tables := []struct {
+		s    string
+		n    int
+		want []string
+	}{
+		{"a b c", 0, []string{"a", "b", "c"}},
+		{"a b c", 1, []string{"a b c"}},
+		{"a b c", 2, []string{"a", "b c"}},
+		{"a b c", 3, []string{"a", "b", "c"}},
+		{"a b c", 4, []string{"a", "b", "c"}},
+	}
+	for _, table := range tables {
+		if got, want := SplitArgs(table.s, table.n), table.want; !reflect.DeepEqual(got, want) {
+			t.Errorf("got: %#v, want: %#v", got, want)
+		}
+	}
+}