From e4a1488b2f9b0d8dbe51f8eda067374985d8b188 Mon Sep 17 00:00:00 2001 From: salanfe Date: Mon, 24 Jun 2019 12:52:50 +0200 Subject: abi: adding the method EventByID and its test (#19359) This function searches for an event+parameters in the ABI and returns it if found. Co-authored-by: Victor Tran Co-authored-by: Guillaume Ballet --- accounts/abi/abi.go | 13 +++++++++ accounts/abi/abi_test.go | 68 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+) (limited to 'accounts') diff --git a/accounts/abi/abi.go b/accounts/abi/abi.go index c5fbc1e77..c3d809e5a 100644 --- a/accounts/abi/abi.go +++ b/accounts/abi/abi.go @@ -21,6 +21,8 @@ import ( "encoding/json" "fmt" "io" + + "github.com/ethereum/go-ethereum/common" ) // The ABI holds information about a contract's context and available @@ -165,3 +167,14 @@ func (abi *ABI) MethodById(sigdata []byte) (*Method, error) { } return nil, fmt.Errorf("no method with id: %#x", sigdata[:4]) } + +// EventByID looks an event up by its topic hash in the +// ABI and returns nil if none found. +func (abi *ABI) EventByID(topic common.Hash) (*Event, error) { + for _, event := range abi.Events { + if bytes.Equal(event.Id().Bytes(), topic.Bytes()) { + return &event, nil + } + } + return nil, fmt.Errorf("no event with id: %#x", topic.Hex()) +} diff --git a/accounts/abi/abi_test.go b/accounts/abi/abi_test.go index 60fe10457..fc6ac628b 100644 --- a/accounts/abi/abi_test.go +++ b/accounts/abi/abi_test.go @@ -931,3 +931,71 @@ func TestABI_MethodById(t *testing.T) { t.Errorf("Expected error, nil is short to decode data") } } + +func TestABI_EventById(t *testing.T) { + tests := []struct { + name string + json string + event string + }{ + { + name: "", + json: `[ + {"type":"event","name":"received","anonymous":false,"inputs":[ + {"indexed":false,"name":"sender","type":"address"}, + {"indexed":false,"name":"amount","type":"uint256"}, + {"indexed":false,"name":"memo","type":"bytes"} + ] + }]`, + event: "received(address,uint256,bytes)", + }, { + name: "", + json: `[ + { "constant": true, "inputs": [], "name": "name", "outputs": [ { "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" }, + { "constant": false, "inputs": [ { "name": "_spender", "type": "address" }, { "name": "_value", "type": "uint256" } ], "name": "approve", "outputs": [ { "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" }, + { "constant": true, "inputs": [], "name": "totalSupply", "outputs": [ { "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" }, + { "constant": false, "inputs": [ { "name": "_from", "type": "address" }, { "name": "_to", "type": "address" }, { "name": "_value", "type": "uint256" } ], "name": "transferFrom", "outputs": [ { "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" }, + { "constant": true, "inputs": [], "name": "decimals", "outputs": [ { "name": "", "type": "uint8" } ], "payable": false, "stateMutability": "view", "type": "function" }, + { "constant": true, "inputs": [ { "name": "_owner", "type": "address" } ], "name": "balanceOf", "outputs": [ { "name": "balance", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" }, + { "constant": true, "inputs": [], "name": "symbol", "outputs": [ { "name": "", "type": "string" } ], "payable": false, "stateMutability": "view", "type": "function" }, + { "constant": false, "inputs": [ { "name": "_to", "type": "address" }, { "name": "_value", "type": "uint256" } ], "name": "transfer", "outputs": [ { "name": "", "type": "bool" } ], "payable": false, "stateMutability": "nonpayable", "type": "function" }, + { "constant": true, "inputs": [ { "name": "_owner", "type": "address" }, { "name": "_spender", "type": "address" } ], "name": "allowance", "outputs": [ { "name": "", "type": "uint256" } ], "payable": false, "stateMutability": "view", "type": "function" }, + { "payable": true, "stateMutability": "payable", "type": "fallback" }, + { "anonymous": false, "inputs": [ { "indexed": true, "name": "owner", "type": "address" }, { "indexed": true, "name": "spender", "type": "address" }, { "indexed": false, "name": "value", "type": "uint256" } ], "name": "Approval", "type": "event" }, + { "anonymous": false, "inputs": [ { "indexed": true, "name": "from", "type": "address" }, { "indexed": true, "name": "to", "type": "address" }, { "indexed": false, "name": "value", "type": "uint256" } ], "name": "Transfer", "type": "event" } + ]`, + event: "Transfer(address,address,uint256)", + }, + } + + for testnum, test := range tests { + abi, err := JSON(strings.NewReader(test.json)) + if err != nil { + t.Error(err) + } + + topic := test.event + topicID := crypto.Keccak256Hash([]byte(topic)) + + event, err := abi.EventByID(topicID) + if err != nil { + t.Fatalf("Failed to look up ABI method: %v, test #%d", err, testnum) + } + if event == nil { + t.Errorf("We should find a event for topic %s, test #%d", topicID.Hex(), testnum) + } + + if event.Id() != topicID { + t.Errorf("Event id %s does not match topic %s, test #%d", event.Id().Hex(), topicID.Hex(), testnum) + } + + unknowntopicID := crypto.Keccak256Hash([]byte("unknownEvent")) + unknownEvent, err := abi.EventByID(unknowntopicID) + if err == nil { + t.Errorf("EventByID should return an error if a topic is not found, test #%d", testnum) + } + if unknownEvent != nil { + t.Errorf("We should not find any event for topic %s, test #%d", unknowntopicID.Hex(), testnum) + } + } +} -- cgit v1.2.3