From 8bfb6b0a67de384baf6cd55095e0bb80c204558a Mon Sep 17 00:00:00 2001
From: Calvin Lau <38898718+calvinaco@users.noreply.github.com>
Date: Mon, 12 Jul 2021 20:26:33 +0800
Subject: [PATCH] rpc: implement `net_listening` and `net_peerCount` JSON-RPC
 endpoints (#252)

* Add net_listening net_peerCount endpoint

* Add test cases

* Use RPC client from context

* Fix lint issue

* Revert unnecessary changes

* Update JSON RPC documentation
---
 docs/basics/json_rpc.md            | 27 +++++++++++++++++++++--
 ethereum/rpc/namespaces/net/api.go | 27 +++++++++++++++++++++--
 scripts/integration-test-all.sh    |  2 +-
 tests/rpc/net_test.go              | 35 ++++++++++++++++++++++++++++++
 4 files changed, 86 insertions(+), 5 deletions(-)
 create mode 100644 tests/rpc/net_test.go

diff --git a/docs/basics/json_rpc.md b/docs/basics/json_rpc.md
index 37632770..f39d32b8 100644
--- a/docs/basics/json_rpc.md
+++ b/docs/basics/json_rpc.md
@@ -18,8 +18,8 @@ Check the JSON-RPC methods and namespaces supported on Ethermint. {synopsis}
 | [`web3_clientVersion`](#web3-clientversion)                                       | Web3      | ✔           |                           |
 | [`web3_sha3`](#web3-sha3)                                                         | Web3      | ✔           |                           |
 | [`net_version`](#net-version)                                                     | Net       | ✔           |                           |
-| `net_peerCount`                                                                   | Net       |             |                           |
-| `net_listening`                                                                   | Net       |             |                           |
+| [`net_peerCount`](#net-peerCount)                                                 | Net       | ✔           |                           |
+| [`net_listening`](#net-listening)                                                 | Net       | ✔           |                           |
 | [`eth_protocolVersion`](#eth-protocolversion)                                     | Eth       | ✔           |                           |
 | [`eth_syncing`](#eth-syncing)                                                     | Eth       | ✔           |                           |
 | [`eth_gasPrice`](#eth-gasprice)                                                   | Eth       | ✔           |                           |
@@ -199,6 +199,29 @@ curl -X POST --data '{"jsonrpc":"2.0","method":"net_version","params":[],"id":1}
 {"jsonrpc":"2.0","id":1,"result":"8"}
 ```
 
+### net_peerCount
+
+Returns the number of peers currently connected to the client.
+```json
+// Request
+curl -X POST --data '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":1}' -H "Content-Type: application/json" http://localhost:8545
+
+// Result
+{"jsonrpc":"2.0","id":1,"result":23}
+```
+
+### net_listening
+
+Returns if client is actively listening for network connections.
+
+```json
+// Request
+curl -X POST --data '{"jsonrpc":"2.0","method":"net_listening","params":[],"id":1}' -H "Content-Type: application/json" http://localhost:8545
+
+// Result
+{"jsonrpc":"2.0","id":1,"result":true}
+```
+
 ## Eth Methods
 
 ### eth_protocolVersion
diff --git a/ethereum/rpc/namespaces/net/api.go b/ethereum/rpc/namespaces/net/api.go
index 741c18df..a8e679ef 100644
--- a/ethereum/rpc/namespaces/net/api.go
+++ b/ethereum/rpc/namespaces/net/api.go
@@ -1,16 +1,18 @@
 package net
 
 import (
+	"context"
 	"fmt"
 
-	ethermint "github.com/tharsis/ethermint/types"
-
 	"github.com/cosmos/cosmos-sdk/client"
+	rpcclient "github.com/tendermint/tendermint/rpc/client"
+	ethermint "github.com/tharsis/ethermint/types"
 )
 
 // PublicAPI is the eth_ prefixed set of APIs in the Web3 JSON-RPC spec.
 type PublicAPI struct {
 	networkVersion uint64
+	tmClient       rpcclient.Client
 }
 
 // NewPublicAPI creates an instance of the public Net Web3 API.
@@ -23,6 +25,7 @@ func NewPublicAPI(clientCtx client.Context) *PublicAPI {
 
 	return &PublicAPI{
 		networkVersion: chainIDEpoch.Uint64(),
+		tmClient:       clientCtx.Client,
 	}
 }
 
@@ -30,3 +33,23 @@ func NewPublicAPI(clientCtx client.Context) *PublicAPI {
 func (s *PublicAPI) Version() string {
 	return fmt.Sprintf("%d", s.networkVersion)
 }
+
+// Listening returns if client is actively listening for network connections.
+func (s *PublicAPI) Listening() bool {
+	ctx := context.Background()
+	netInfo, err := s.tmClient.NetInfo(ctx)
+	if err != nil {
+		return false
+	}
+	return netInfo.Listening
+}
+
+// PeerCount returns the number of peers currently connected to the client.
+func (s *PublicAPI) PeerCount() int {
+	ctx := context.Background()
+	netInfo, err := s.tmClient.NetInfo(ctx)
+	if err != nil {
+		return 0
+	}
+	return len(netInfo.Peers)
+}
diff --git a/scripts/integration-test-all.sh b/scripts/integration-test-all.sh
index 2e28dca6..3c581ad9 100755
--- a/scripts/integration-test-all.sh
+++ b/scripts/integration-test-all.sh
@@ -61,7 +61,7 @@ fi
 
 # Compile ethermint
 echo "compiling ethermint"
-make build-ethermint
+make build
 
 # PID array declaration
 arr=()
diff --git a/tests/rpc/net_test.go b/tests/rpc/net_test.go
new file mode 100644
index 00000000..15a34ad5
--- /dev/null
+++ b/tests/rpc/net_test.go
@@ -0,0 +1,35 @@
+package rpc
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNet_Version(t *testing.T) {
+	rpcRes := Call(t, "net_version", []string{})
+
+	var res string
+	err := json.Unmarshal(rpcRes.Result, &res)
+	require.NoError(t, err)
+	require.Equal(t, "2", res)
+}
+
+func TestNet_Listening(t *testing.T) {
+	rpcRes := Call(t, "net_listening", []string{})
+
+	var res bool
+	err := json.Unmarshal(rpcRes.Result, &res)
+	require.NoError(t, err)
+	require.True(t, res)
+}
+
+func TestNet_PeerCount(t *testing.T) {
+	rpcRes := Call(t, "net_peerCount", []string{})
+
+	var res int
+	err := json.Unmarshal(rpcRes.Result, &res)
+	require.NoError(t, err)
+	require.Equal(t, 0, res)
+}