add custom argument matching

expectations.go

@@ -6,6 +6,12 @@ import (
     "regexp"
 )
 
+// Argument interface allows to match
+// any argument in specific way
+type Argument interface {
+    Match(driver.Value) bool
+}
+
 // an expectation interface
 type expectation interface {
     fulfilled() bool
@@ -47,6 +53,13 @@ func (e *queryBasedExpectation) argsMatches(args []driver.Value) bool {
         return false
     }
     for k, v := range args {
+        matcher, ok := e.args[k].(Argument)
+        if ok {
+            if !matcher.Match(v) {
+                return false
+            }
+            continue
+        }
         vi := reflect.ValueOf(v)
         ai := reflect.ValueOf(e.args[k])
         switch vi.Kind() {

expectations_test.go

@@ -6,6 +6,13 @@ import (
     "time"
 )
 
+type matcher struct {
+}
+
+func (m matcher) Match(driver.Value) bool {
+    return true
+}
+
 func TestQueryExpectationArgComparison(t *testing.T) {
     e := &queryBasedExpectation{}
     against := []driver.Value{5}
@@ -44,4 +51,9 @@ func TestQueryExpectationArgComparison(t *testing.T) {
     if !e.argsMatches(against) {
         t.Error("arguments should match (time will be compared only by type), but it did not")
     }
+
+    against = []driver.Value{5, matcher{}}
+    if !e.argsMatches(against) {
+        t.Error("arguments should match, but it did not")
+    }
 }