Implement private clone method to support fluent API

expecter.go

@@ -4,23 +4,19 @@ import (
 	"fmt"
 )
 
-// Expecter is the exported struct used for setting expectations
-type Expecter struct {
-	adapter Adapter
-}
-
 // AdapterFactory is a generic interface for arbitrary adapters that satisfy
 // the interface. variadic args are passed to gorm.Open.
 type AdapterFactory func(dialect string, args ...interface{}) (error, *DB, Adapter)
 
-func (h *Expecter) ExpectFirst(model interface{}) ExpectedQuery {
-	fmt.Printf("Expecting query: %s", "some query\n")
-	return h.adapter.ExpectQuery("some sql")
-}
+// Expecter is the exported struct used for setting expectations
+type Expecter struct {
+	Value   interface{}
+	adapter Adapter
+	search  *search
+	values  map[string]interface{}
 
-func (h *Expecter) ExpectFind(model interface{}) ExpectedQuery {
-	fmt.Println("Expecting query: %s", "some query involving Find")
-	return h.adapter.ExpectQuery("some find condition")
+	// globally scoped expecter
+	root *Expecter
 }
 
 // NewDefaultExpecter returns a Expecter powered by go-sqlmock
@@ -44,3 +40,30 @@ func NewExpecter(fn AdapterFactory, dialect string, args ...interface{}) (error,
 
 	return nil, gormDb, &Expecter{adapter: adapter}
 }
+
+/* PUBLIC METHODS */
+
+func (h *Expecter) ExpectFirst(model interface{}) ExpectedQuery {
+	fmt.Printf("Expecting query: %s", "some query\n")
+	return h.adapter.ExpectQuery("some sql")
+}
+
+func (h *Expecter) ExpectFind(model interface{}) ExpectedQuery {
+	fmt.Println("Expecting query: %s", "some query involving Find")
+	return h.adapter.ExpectQuery("some find condition")
+}
+
+/* PRIVATE METHODS */
+
+// clone is similar to DB.clone, and ensures that the root Expecter is not
+// polluted with subsequent search constraints
+func (h *Expecter) clone() *Expecter {
+	expecterCopy := &Expecter{
+		adapter: h.adapter,
+		root:    h.root,
+		values:  map[string]interface{}{},
+		Value:   h.Value,
+	}
+
+	return expecterCopy
+}