Merge pull request #172 from mimir-d/bugfix/handle_nil_in_paramexpander

handle nils correctly in ParamExpander
linuxboot · May 9, 2024 · 1b1abe5 · 1b1abe5
2 parents 6ff4d0f + d494b08
commit 1b1abe5
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Showing 2 changed files with 22 additions and 2 deletions.
diff --git a/pkg/test/param_expander.go b/pkg/test/param_expander.go
@@ -74,6 +74,12 @@ func (pe *ParamExpander) ExpandObject(obj interface{}, out interface{}) error {
 			vout.Set(val)
 
 		case reflect.Map:
+			if vin.IsNil() {
+				// handle nil maps, eg. map[T]U(nil)
+				vout.Set(vin)
+				break
+			}
+
 			val := reflect.MakeMap(vin.Type())
 			iter := vin.MapRange()
 			for iter.Next() {
@@ -112,6 +118,12 @@ func (pe *ParamExpander) ExpandObject(obj interface{}, out interface{}) error {
 			vout.Set(val.Elem())
 
 		case reflect.Slice:
+			if vin.IsNil() {
+				// handle nil slices, eg. []T(nil)
+				vout.Set(vin)
+				break
+			}
+
 			elemType := vin.Type().Elem()
 			len := vin.Len()
 

diff --git a/pkg/test/param_expander_test.go b/pkg/test/param_expander_test.go
@@ -165,12 +165,18 @@ func TestParamExpander(t *testing.T) {
 
 	t.Run("nulls", func(t *testing.T) {
 		type testObj struct {
-			Str  *string
-			Intf any
+			Str    *string
+			Intf   any
+			Ints   []int
+			IntMap map[int]int
 		}
 
 		// both fields null
 		input := &testObj{}
+		require.Nil(t, input.Str)
+		require.Nil(t, input.Intf)
+		require.Nil(t, input.Ints)
+		require.Nil(t, input.IntMap)
 
 		e := NewParamExpander(target, &mockVars{})
 
@@ -180,5 +186,7 @@ func TestParamExpander(t *testing.T) {
 
 		require.Nil(t, out.Str)
 		require.Nil(t, out.Intf)
+		require.Nil(t, out.Ints)
+		require.Nil(t, out.IntMap)
 	})
 }