package mergo_test import ( "testing" "github.com/imdario/mergo" ) type DstStructIssue84 struct { A int B int C int } type DstNestedStructIssue84 struct { A struct { A int B int C int } B int C int } func TestIssue84MergeMapWithNilValueToStructWithOverride(t *testing.T) { p1 := DstStructIssue84{ A: 0, B: 1, C: 2, } p2 := map[string]interface{}{ "A": 3, "B": 4, "C": 0, } if err := mergo.Map(&p1, p2, mergo.WithOverride); err != nil { t.Errorf("Error during the merge: %v", err) } if p1.C != 0 { t.Error("C field should become '0'") } } func TestIssue84MergeMapWithoutKeyExistsToStructWithOverride(t *testing.T) { p1 := DstStructIssue84{ A: 0, B: 1, C: 2, } p2 := map[string]interface{}{ "A": 3, "B": 4, } if err := mergo.Map(&p1, p2, mergo.WithOverride); err != nil { t.Errorf("Error during the merge: %v", err) } if p1.C != 2 { t.Error("C field should be '2'") } } func TestIssue84MergeNestedMapWithNilValueToStructWithOverride(t *testing.T) { p1 := DstNestedStructIssue84{ A: struct { A int B int C int }{A: 1, B: 2, C: 0}, B: 0, C: 2, } p2 := map[string]interface{}{ "A": map[string]interface{}{ "A": 0, "B": 0, "C": 5, }, "B": 4, "C": 0, } if err := mergo.Map(&p1, p2, mergo.WithOverride); err != nil { t.Errorf("Error during the merge: %v", err) } if p1.B != 4 { t.Error("A.C field should become '4'") } if p1.A.C != 5 { t.Error("A.C field should become '5'") } if p1.A.B != 0 || p1.A.A != 0 { t.Error("A.A and A.B field should become '0'") } }