Merge pull request #95 from pinpt/filter_stringify

add string to filter so we can debug

filterexpr/filterexpr.go

@@ -10,6 +10,9 @@ import (
 type Filter interface {
 	// Test will return true if the filter expression matches the map
 	Test(kv map[string]interface{}) bool
+
+	// String will return a string representation
+	String() string
 }
 
 type filter struct {
@@ -23,6 +26,10 @@ func (f *filter) Test(kv map[string]interface{}) bool {
 	return f.expr.Test(kv)
 }
 
+func (f *filter) String() string {
+	return f.expr.String()
+}
+
 // Compile will compile the filter expression as a string in Filter which can be saved and invoked and is thread safe
 func Compile(expr string) (Filter, error) {
 	object, err := ParseReader("", strings.NewReader(expr), MaxExpressions(150000))

filterexpr/filterexpr_test.go

@@ -171,3 +171,10 @@ func TestABigAsExpression(t *testing.T) {
 	assert.NoError(err)
 	assert.True(filter.Test(map[string]interface{}{"model": "activityfeed.Feed", "user_id": "40bfb0d341249a58"}))
 }
+
+func TestStringify(t *testing.T) {
+	assert := assert.New(t)
+	filter, err := Compile(`user-id:"a"`)
+	assert.NoError(err)
+	assert.Equal("ExpressionGroup[[Expression[Node[user-id=a],,<nil>]]]", filter.String())
+}