add AnyArg func to provide any kind of argument matcher

Author: l3pp4rd

README.md

@@ -188,7 +188,8 @@ It only asserts that argument is of `time.Time` type.
 
 ## Changes
 
-
+- **2016-02-23** - added **sqlmock.AnyArg()** function to provide any kind
+  of argument matcher.
 - **2016-02-23** - convert expected arguments to driver.Value as natural
   driver does, the change may affect time.Time comparison and will be
   stricter. See [issue](https://github.com/DATA-DOG/go-sqlmock/issues/31).

argument.go

@@ -0,0 +1,24 @@
+package sqlmock
+
+import "database/sql/driver"
+
+// Argument interface allows to match
+// any argument in specific way when used with
+// ExpectedQuery and ExpectedExec expectations.
+type Argument interface {
+	Match(driver.Value) bool
+}
+
+// AnyArg will return an Argument which can
+// match any kind of arguments.
+//
+// Useful for time.Time or similar kinds of arguments.
+func AnyArg() Argument {
+	return anyArgument{}
+}
+
+type anyArgument struct{}
+
+func (a anyArgument) Match(_ driver.Value) bool {
+	return true
+}

expectations.go

@@ -8,13 +8,6 @@ import (
 	"sync"
 )
 
-// Argument interface allows to match
-// any argument in specific way when used with
-// ExpectedQuery and ExpectedExec expectations.
-type Argument interface {
-	Match(driver.Value) bool
-}
-
 // an expectation interface
 type expectation interface {
 	fulfilled() bool

expectations_test.go

@@ -8,13 +8,6 @@ import (
 	"time"
 )
 
-type matcher struct {
-}
-
-func (m matcher) Match(driver.Value) bool {
-	return true
-}
-
 func TestQueryExpectationArgComparison(t *testing.T) {
 	e := &queryBasedExpectation{}
 	against := []driver.Value{int64(5)}
@@ -53,7 +46,7 @@ func TestQueryExpectationArgComparison(t *testing.T) {
 		t.Error("arguments should match, but it did not")
 	}
 
-	e.args = []driver.Value{5, matcher{}}
+	e.args = []driver.Value{5, AnyArg()}
 	if err := e.argsMatches(against); err != nil {
 		t.Errorf("arguments should match, but it did not: %s", err)
 	}