From 115b1c38ac45d83b90770ab80e39665e093fe804 Mon Sep 17 00:00:00 2001
From: Guillaume Ballet <gballet@gmail.com>
Date: Tue, 15 Jan 2019 16:45:52 +0100
Subject: [PATCH] accounts/abi: Add tests for reflection ahead of refactor
 (#18434)

---
 accounts/abi/reflect_test.go | 191 +++++++++++++++++++++++++++++++++++
 1 file changed, 191 insertions(+)
 create mode 100644 accounts/abi/reflect_test.go

diff --git a/accounts/abi/reflect_test.go b/accounts/abi/reflect_test.go
new file mode 100644
index 000000000..c425e6e54
--- /dev/null
+++ b/accounts/abi/reflect_test.go
@@ -0,0 +1,191 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"reflect"
+	"testing"
+)
+
+type reflectTest struct {
+	name  string
+	args  []string
+	struc interface{}
+	want  map[string]string
+	err   string
+}
+
+var reflectTests = []reflectTest{
+	{
+		name: "OneToOneCorrespondance",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "MissingFieldsInStruct",
+		args: []string{"fieldA", "fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "MoreFieldsInStructThanArgs",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "MissingFieldInArgs",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int `abi:"fieldB"`
+		}{},
+		err: "struct: abi tag 'fieldB' defined but not found in abi",
+	},
+	{
+		name: "NoAbiDescriptor",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "NoArgs",
+		args: []string{},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+		}{},
+		err: "struct: abi tag 'fieldA' defined but not found in abi",
+	},
+	{
+		name: "DifferentName",
+		args: []string{"fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldB"`
+		}{},
+		want: map[string]string{
+			"fieldB": "FieldA",
+		},
+	},
+	{
+		name: "DifferentName",
+		args: []string{"fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldB"`
+		}{},
+		want: map[string]string{
+			"fieldB": "FieldA",
+		},
+	},
+	{
+		name: "MultipleFields",
+		args: []string{"fieldA", "fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int `abi:"fieldB"`
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+			"fieldB": "FieldB",
+		},
+	},
+	{
+		name: "MultipleFieldsABIMissing",
+		args: []string{"fieldA", "fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+			"fieldB": "FieldB",
+		},
+	},
+	{
+		name: "NameConflict",
+		args: []string{"fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldB"`
+			FieldB int
+		}{},
+		err: "abi: multiple variables maps to the same abi field 'fieldB'",
+	},
+	{
+		name: "Underscored",
+		args: []string{"_"},
+		struc: struct {
+			FieldA int
+		}{},
+		err: "abi: purely underscored output cannot unpack to struct",
+	},
+	{
+		name: "DoubleMapping",
+		args: []string{"fieldB", "fieldC", "fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldC"`
+			FieldB int
+		}{},
+		err: "abi: multiple outputs mapping to the same struct field 'FieldA'",
+	},
+	{
+		name: "AlreadyMapped",
+		args: []string{"fieldB", "fieldB"},
+		struc: struct {
+			FieldB int `abi:"fieldB"`
+		}{},
+		err: "struct: abi tag in 'FieldB' already mapped",
+	},
+}
+
+func TestReflectNameToStruct(t *testing.T) {
+	for _, test := range reflectTests {
+		t.Run(test.name, func(t *testing.T) {
+			m, err := mapArgNamesToStructFields(test.args, reflect.ValueOf(test.struc))
+			if len(test.err) > 0 {
+				if err == nil || err.Error() != test.err {
+					t.Fatalf("Invalid error: expected %v, got %v", test.err, err)
+				}
+			} else {
+				if err != nil {
+					t.Fatalf("Unexpected error: %v", err)
+				}
+				for fname := range test.want {
+					if m[fname] != test.want[fname] {
+						t.Fatalf("Incorrect value for field %s: expected %v, got %v", fname, test.want[fname], m[fname])
+					}
+				}
+			}
+		})
+	}
+}