From 3c8032ca7d5fa2a41399c555bd2e97236213cf66 Mon Sep 17 00:00:00 2001
From: nanmu42 <i@nanmu.me>
Date: Tue, 20 Nov 2018 16:06:47 +0800
Subject: [PATCH 1/3] [fix] workaround for missing tokenDecimal for tokentx
 calls

Note on a Etherscan bug:
Some ERC20 contract does not have valid decimals information in Etherscan.
When that happen TokenName, TokenSymbol are empty strings,
and TokenDecimal is 0.

More information can be found at:
https://github.com/nanmu42/etherscan-api/issues/8
---
 account.go          |  8 ++++++++
 account_e2e_test.go | 12 ++++++++++++
 client.go           |  7 ++++++-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/account.go b/account.go
index 85d48fa..e5b9f2c 100644
--- a/account.go
+++ b/account.go
@@ -79,6 +79,14 @@ func (c *Client) InternalTxByAddress(address string, startBlock *int, endBlock *
 // contract address and/or from/to address.
 //
 // leave undesired condition to nil.
+//
+// Note on a Etherscan bug:
+// Some ERC20 contract does not have valid decimals information in Etherscan.
+// When that happen TokenName, TokenSymbol are empty strings,
+// and TokenDecimal is 0.
+//
+// More information can be found at:
+// https://github.com/nanmu42/etherscan-api/issues/8
 func (c *Client) ERC20Transfers(contractAddress, address *string, startBlock *int, endBlock *int, page int, offset int) (txs []ERC20Transfer, err error) {
 	param := M{
 		"page":   page,
diff --git a/account_e2e_test.go b/account_e2e_test.go
index c489697..fffd9fa 100644
--- a/account_e2e_test.go
+++ b/account_e2e_test.go
@@ -73,6 +73,7 @@ func TestClient_ERC20Transfers(t *testing.T) {
 	const (
 		wantLen1 = 3
 		wantLen2 = 458
+		wantLen3 = 2
 	)
 
 	var a, b = 3273004, 3328071
@@ -92,6 +93,17 @@ func TestClient_ERC20Transfers(t *testing.T) {
 	if len(txs) != wantLen2 {
 		t.Errorf("got txs length %v, want %v", len(txs), wantLen2)
 	}
+
+	// some ERC20 contract does not have valid decimals information in Etherscan,
+	// which brings errors like `json: invalid use of ,string struct tag, trying to unmarshal "" into uint8`
+	var specialContract = "0x5eac95ad5b287cf44e058dcf694419333b796123"
+	var specialStartHeight = 6024142
+	var specialEndHeight = 6485274
+	txs, err = api.ERC20Transfers(&specialContract, nil, &specialStartHeight, &specialEndHeight, 1, 500)
+	noError(t, err, "api.ERC20Transfers 2")
+	if len(txs) != wantLen3 {
+		t.Errorf("got txs length %v, want %v", len(txs), wantLen3)
+	}
 }
 
 func TestClient_BlocksMinedByAddress(t *testing.T) {
diff --git a/client.go b/client.go
index e7422cd..3750998 100644
--- a/client.go
+++ b/client.go
@@ -134,7 +134,12 @@ func (c *Client) call(module, action string, param map[string]interface{}, outco
 		return
 	}
 
-	err = json.Unmarshal(envelope.Result, outcome)
+	// workaround for missing tokenDecimal for some tokentx calls
+	if action == "tokentx" {
+		err = json.Unmarshal(bytes.Replace(envelope.Result, []byte(`"tokenDecimal":""`), []byte(`"tokenDecimal":"0"`), -1), outcome)
+	} else {
+		err = json.Unmarshal(envelope.Result, outcome)
+	}
 	if err != nil {
 		err = wrapErr(err, "json unmarshal outcome")
 		return

From 58eeb0af190a37817f3754a793e75cccae66a9f6 Mon Sep 17 00:00:00 2001
From: nanmu42 <i@nanmu.me>
Date: Tue, 20 Nov 2018 16:08:21 +0800
Subject: [PATCH 2/3] [dev] add a 30-second timeout for client

---
 client.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/client.go b/client.go
index 3750998..b981d59 100644
--- a/client.go
+++ b/client.go
@@ -15,6 +15,7 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"time"
 )
 
 // Client etherscan API client
@@ -41,7 +42,9 @@ type Client struct {
 // please use pre-defined network value
 func New(network Network, APIKey string) *Client {
 	return &Client{
-		coon:    &http.Client{},
+		coon: &http.Client{
+			Timeout: 30 * time.Second,
+		},
 		network: network,
 		key:     APIKey,
 		baseURL: fmt.Sprintf(`https://%s.etherscan.io/api?`, network.SubDomain()),

From 8f0b304c514eab3a29eb3418a25ebb26867dab94 Mon Sep 17 00:00:00 2001
From: nanmu42 <i@nanmu.me>
Date: Tue, 20 Nov 2018 16:11:39 +0800
Subject: [PATCH 3/3] [fix] typo

---
 account.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/account.go b/account.go
index e5b9f2c..0effe2c 100644
--- a/account.go
+++ b/account.go
@@ -82,7 +82,7 @@ func (c *Client) InternalTxByAddress(address string, startBlock *int, endBlock *
 //
 // Note on a Etherscan bug:
 // Some ERC20 contract does not have valid decimals information in Etherscan.
-// When that happen TokenName, TokenSymbol are empty strings,
+// When that happens, TokenName, TokenSymbol are empty strings,
 // and TokenDecimal is 0.
 //
 // More information can be found at: