document time.Time argument matching example

Author: l3pp4rd

README.md

@@ -142,6 +142,46 @@ func TestShouldRollbackStatUpdatesOnFailure(t *testing.T) {
 }
 ```
 
+## Matching arguments like time.Time
+
+There may be arguments which are of `struct` type and cannot be compared easily by value like `time.Time`. In this case
+**sqlmock** provides an [Argument](https://godoc.org/github.com/DATA-DOG/go-sqlmock#Argument) interface which
+can be used in more sophisticated matching. Here is a simple example of time argument matching:
+
+``` go
+type AnyTime struct{}
+
+// Match satisfies sqlmock.Argument interface
+func (a AnyTime) Match(v driver.Value) bool {
+	_, ok := v.(time.Time)
+	return ok
+}
+
+func TestAnyTimeArgument(t *testing.T) {
+	t.Parallel()
+	db, mock, err := New()
+	if err != nil {
+		t.Errorf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer db.Close()
+
+	mock.ExpectExec("INSERT INTO users").
+		WithArgs("john", AnyTime{}).
+		WillReturnResult(NewResult(1, 1))
+
+	_, err = db.Exec("INSERT INTO users(name, created_at) VALUES (?, ?)", "john", time.Now())
+	if err != nil {
+		t.Errorf("error '%s' was not expected, while inserting a row", err)
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled expections: %s", err)
+	}
+}
+```
+
+It only asserts that argument is of `time.Time` type.
+
 ## Run tests
 
     go test -race

argument_test.go

@@ -0,0 +1,37 @@
+package sqlmock
+
+import (
+	"database/sql/driver"
+	"testing"
+	"time"
+)
+
+type AnyTime struct{}
+
+// Match satisfies sqlmock.Argument interface
+func (a AnyTime) Match(v driver.Value) bool {
+	_, ok := v.(time.Time)
+	return ok
+}
+
+func TestAnyTimeArgument(t *testing.T) {
+	t.Parallel()
+	db, mock, err := New()
+	if err != nil {
+		t.Errorf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer db.Close()
+
+	mock.ExpectExec("INSERT INTO users").
+		WithArgs("john", AnyTime{}).
+		WillReturnResult(NewResult(1, 1))
+
+	_, err = db.Exec("INSERT INTO users(name, created_at) VALUES (?, ?)", "john", time.Now())
+	if err != nil {
+		t.Errorf("error '%s' was not expected, while inserting a row", err)
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("there were unfulfilled expections: %s", err)
+	}
+}