From e4a1488b2f9b0d8dbe51f8eda067374985d8b188 Mon Sep 17 00:00:00 2001
From: salanfe <salanfe@users.noreply.github.com>
Date: Mon, 24 Jun 2019 12:52:50 +0200
Subject: [PATCH] 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 <vu.tran54@gmail.com>
Co-authored-by: Guillaume Ballet <gballet@gmail.com>
---
accounts/abi/abi.go | 13 ++++++++
accounts/abi/abi_test.go | 68 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 81 insertions(+)
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)
+ }
+ }
+}
--
GitLab