Add a unit test for the conversion

collector/netdev_freebsd.go

@@ -53,19 +53,23 @@ func getNetDevStats(ignore *regexp.Regexp) (map[string]map[string]string, error)
 			devStats := map[string]string{}
 			data := (*C.struct_if_data)(ifa.ifa_data)
 
-			devStats["receive_packets"] = strconv.FormatUint(uint64(data.ifi_ipackets), 10)
-			devStats["transmit_packets"] = strconv.FormatUint(uint64(data.ifi_opackets), 10)
-			devStats["receive_errs"] = strconv.FormatUint(uint64(data.ifi_ierrors), 10)
-			devStats["transmit_errs"] = strconv.FormatUint(uint64(data.ifi_oerrors), 10)
-			devStats["receive_bytes"] = strconv.FormatUint(uint64(data.ifi_ibytes), 10)
-			devStats["transmit_bytes"] = strconv.FormatUint(uint64(data.ifi_obytes), 10)
-			devStats["receive_multicast"] = strconv.FormatUint(uint64(data.ifi_imcasts), 10)
-			devStats["transmit_multicast"] = strconv.FormatUint(uint64(data.ifi_omcasts), 10)
-			devStats["receive_drop"] = strconv.FormatUint(uint64(data.ifi_iqdrops), 10)
-			devStats["transmit_drop"] = strconv.FormatUint(uint64(data.ifi_oqdrops), 10)
+			devStats["receive_packets"] = convertFreeBSDCPUTime(uint64(data.ifi_ipackets))
+			devStats["transmit_packets"] = convertFreeBSDCPUTime(uint64(data.ifi_opackets))
+			devStats["receive_errs"] = convertFreeBSDCPUTime(uint64(data.ifi_ierrors))
+			devStats["transmit_errs"] = convertFreeBSDCPUTime(uint64(data.ifi_oerrors))
+			devStats["receive_bytes"] = convertFreeBSDCPUTime(uint64(data.ifi_ibytes))
+			devStats["transmit_bytes"] = convertFreeBSDCPUTime(uint64(data.ifi_obytes))
+			devStats["receive_multicast"] = convertFreeBSDCPUTime(uint64(data.ifi_imcasts))
+			devStats["transmit_multicast"] = convertFreeBSDCPUTime(uint64(data.ifi_omcasts))
+			devStats["receive_drop"] = convertFreeBSDCPUTime(uint64(data.ifi_iqdrops))
+			devStats["transmit_drop"] = convertFreeBSDCPUTime(uint64(data.ifi_oqdrops))
 			netDev[dev] = devStats
 		}
 	}
 
 	return netDev, nil
 }
+
+func convertFreeBSDCPUTime(counter uint64) string {
+	return strconv.FormatUint(counter, 10)
+}

collector/netdev_freebsd_test.go

@@ -0,0 +1,50 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package collector
+
+import "testing"
+
+type uintToStringTest struct {
+	in  uint64
+	out string
+}
+
+var uinttostringtests = []uintToStringTest{
+	// Copied base10 values from strconv's tests:
+	{0, "0"},
+	{1, "1"},
+	{12345678, "12345678"},
+	{1<<31 - 1, "2147483647"},
+	{1 << 31, "2147483648"},
+	{1<<31 + 1, "2147483649"},
+	{1<<32 - 1, "4294967295"},
+	{1 << 32, "4294967296"},
+	{1<<32 + 1, "4294967297"},
+	{1 << 50, "1125899906842624"},
+	{1<<63 - 1, "9223372036854775807"},
+
+	// Some values that convert correctly on amd64, but not on i386.
+	{0x1bf0c640a, "7500227594"},
+	{0xbee5df75, "3202735989"},
+}
+
+func TestUintToString(t *testing.T) {
+	for _, test := range uinttostringtests {
+		is := convertFreeBSDCPUTime(test.in)
+		if is != test.out {
+			t.Errorf("convertFreeBSDCPUTime(%v) = %v want %v",
+				test.in, is, test.out)
+		}
+	}
+}