more tests and fixed a bug the tests found. Cleaned up the documentation. Renamed Backups to MaxBackups.

testing_test.go

@@ -8,10 +8,14 @@ import (
 	"testing"
 )
 
+// assert will log the given message if condition is false.
 func assert(condition bool, t testing.TB, msg string, v ...interface{}) {
 	assertUp(condition, t, 1, msg, v...)
 }
 
+// assertUp is like assert, but used inside helper functions, to ensure that
+// the file and line number reported by failures corresponds to one or more
+// levels up the stack.
 func assertUp(condition bool, t testing.TB, caller int, msg string, v ...interface{}) {
 	if !condition {
 		_, file, line, _ := runtime.Caller(caller + 1)
@@ -21,10 +25,14 @@ func assertUp(condition bool, t testing.TB, caller int, msg string, v ...interfa
 	}
 }
 
+// equals tests that the two values are equal according to reflect.DeepEqual.
 func equals(exp, act interface{}, t testing.TB) {
 	equalsUp(exp, act, t, 1)
 }
 
+// equalsUp is like equals, but used inside helper functions, to ensure that the
+// file and line number reported by failures corresponds to one or more levels
+// up the stack.
 func equalsUp(exp, act interface{}, t testing.TB, caller int) {
 	if !reflect.DeepEqual(exp, act) {
 		_, file, line, _ := runtime.Caller(caller + 1)
@@ -34,10 +42,15 @@ func equalsUp(exp, act interface{}, t testing.TB, caller int) {
 	}
 }
 
+// isNil reports a failure if the given value is not nil.  Note that values
+// which cannot be nil will always fail this check.
 func isNil(obtained interface{}, t testing.TB) {
 	isNilUp(obtained, t, 1)
 }
 
+// isNilUp is like isNil, but used inside helper functions, to ensure that the
+// file and line number reported by failures corresponds to one or more levels
+// up the stack.
 func isNilUp(obtained interface{}, t testing.TB, caller int) {
 	if !_isNil(obtained) {
 		_, file, line, _ := runtime.Caller(caller + 1)
@@ -46,10 +59,14 @@ func isNilUp(obtained interface{}, t testing.TB, caller int) {
 	}
 }
 
+// notNil reports a failure if the given value is nil.
 func notNil(obtained interface{}, t testing.TB) {
 	notNilUp(obtained, t, 1)
 }
 
+// notNilUp is like notNil, but used inside helper functions, to ensure that the
+// file and line number reported by failures corresponds to one or more levels
+// up the stack.
 func notNilUp(obtained interface{}, t testing.TB, caller int) {
 	if _isNil(obtained) {
 		_, file, line, _ := runtime.Caller(caller + 1)
@@ -58,6 +75,8 @@ func notNilUp(obtained interface{}, t testing.TB, caller int) {
 	}
 }
 
+// _isNil is a helper function for isNil and notNil, and should not be used
+// directly.
 func _isNil(obtained interface{}) bool {
 	if obtained == nil {
 		return true