helper/schema: more tests

helper/schema/schema.go

@@ -143,6 +143,11 @@ func (m schemaMap) diffList(
 		return fmt.Errorf("%s: must be a list", k)
 	}
 
+	// If this field is required, then it must also be non-empty
+	if len(vs) == 0 && schema.Required {
+		return fmt.Errorf("%s: required field is not set", k)
+	}
+
 	// Diff the count no matter what
 	countSchema := &Schema{
 		Type:     TypeInt,

helper/schema/schema_test.go

@@ -355,6 +355,87 @@ func TestSchemaMap_Diff(t *testing.T) {
 
 			Err: false,
 		},
+
+		{
+			Schema: map[string]*Schema{
+				"ingress": &Schema{
+					Type:     TypeList,
+					Required: true,
+					Elem: &Resource{
+						Schema: map[string]*Schema{
+							"from": &Schema{
+								Type:     TypeInt,
+								Required: true,
+							},
+						},
+					},
+				},
+			},
+
+			State: nil,
+
+			Config: map[string]interface{}{},
+
+			Diff: nil,
+
+			Err: true,
+		},
+
+		{
+			Schema: map[string]*Schema{
+				"ingress": &Schema{
+					Type:     TypeList,
+					Required: true,
+					Elem: &Resource{
+						Schema: map[string]*Schema{
+							"from": &Schema{
+								Type:     TypeInt,
+								Required: true,
+							},
+						},
+					},
+				},
+			},
+
+			State: nil,
+
+			Config: map[string]interface{}{
+				"ingress": []interface{}{},
+			},
+
+			Diff: nil,
+
+			Err: true,
+		},
+
+		{
+			Schema: map[string]*Schema{
+				"ingress": &Schema{
+					Type:     TypeList,
+					Required: true,
+					Elem: &Resource{
+						Schema: map[string]*Schema{
+							"from": &Schema{
+								Type:     TypeInt,
+								Required: true,
+							},
+						},
+					},
+				},
+			},
+
+			State: nil,
+
+			Config: map[string]interface{}{
+				"ingress": []interface{}{
+					map[string]interface{}{},
+				},
+			},
+
+			Diff: nil,
+
+			Err: true,
+		},
 	}
 
 	for i, tc := range cases {