helper: Add new bytesToString function and tests

Signed-off-by: David O'Rourke <david.orourke@gmail.com>

collector/helper.go

@@ -14,6 +14,7 @@
 package collector
 
 import (
+	"bytes"
 	"io/ioutil"
 	"strconv"
 	"strings"
@@ -30,3 +31,16 @@ func readUintFromFile(path string) (uint64, error) {
 	}
 	return value, nil
 }
+
+// Take a []byte{} and return a string based on null termination.
+// This is useful for situations where the OS has returned a null terminated
+// string to use.
+// If this function happens to receive a byteArray that contains no nulls, we
+// simply convert the array to a string with no bounding.
+func bytesToString(byteArray []byte) string {
+	n := bytes.IndexByte(byteArray, 0)
+	if n < 0 {
+		return string(byteArray)
+	}
+	return string(byteArray[:n])
+}