module/eth: add Syncing() (#230)

* module/eth: added `Syncing()`

* added doc

---------

Co-authored-by: lmittmann <lmittmann@users.noreply.github.com>

README.md

@@ -194,6 +194,7 @@ List of supported RPC methods for [`w3.Client`](https://pkg.go.dev/github.com/lm
 | `eth_getUncleByBlockNumberAndIndex`       | `eth.UncleByBlockNumberAndIndex(number *big.Int, index uint).Returns(uncle **types.Header)`
 | `eth_getUncleCountByBlockHash`            | `eth.UncleCountByBlockHash(hash common.Hash).Returns(count *uint)`
 | `eth_getUncleCountByBlockNumber`          | `eth.UncleCountByBlockNumber(number *big.Int).Returns(count *uint)`
+| `eth_syncing`                             | `eth.Syncing().Returns(syncing *bool)`
 
 ### [`debug`](https://pkg.go.dev/github.com/lmittmann/w3/module/debug)
 

docs/pages/rpc-methods/eth.mdx

@@ -241,3 +241,12 @@ client.Call(
     eth.UncleCountByBlockNumber(number).Returns(&count),
 )
 ```
+
+## `eth_syncing`
+`Syncing` requests the syncing status of the node.
+```go {3}
+var syncing bool
+client.Call(
+    eth.Syncing().Returns(&syncing),
+)
+```

module/eth/syncing.go

@@ -0,0 +1,30 @@
+package eth
+
+import (
+	"github.com/lmittmann/w3/internal/module"
+	"github.com/lmittmann/w3/w3types"
+)
+
+// Syncing requests the syncing status of the node.
+func Syncing() w3types.RPCCallerFactory[bool] {
+	return module.NewFactory(
+		"eth_syncing",
+		[]any{},
+		module.WithRetWrapper(syncingRetWrapper),
+	)
+}
+
+func syncingRetWrapper(ret *bool) any {
+	return (*syncingBool)(ret)
+}
+
+type syncingBool bool
+
+func (s *syncingBool) UnmarshalJSON(b []byte) error {
+	if string(b) == "false" {
+		*s = false
+	} else {
+		*s = true
+	}
+	return nil
+}

module/eth/syncing_test.go

@@ -0,0 +1,23 @@
+package eth_test
+
+import (
+	"testing"
+
+	"github.com/lmittmann/w3/module/eth"
+	"github.com/lmittmann/w3/rpctest"
+)
+
+func TestSyncing(t *testing.T) {
+	rpctest.RunTestCases(t, []rpctest.TestCase[bool]{
+		{
+			Golden:  "syncing__false",
+			Call:    eth.Syncing(),
+			WantRet: false,
+		},
+		{
+			Golden:  "syncing__true",
+			Call:    eth.Syncing(),
+			WantRet: true,
+		},
+	})
+}

module/eth/testdata/syncing__false.golden

@@ -0,0 +1,2 @@
+> {"jsonrpc":"2.0","id":1,"method":"eth_syncing","params":[]}
+< {"jsonrpc":"2.0","id":1,"result":false}

module/eth/testdata/syncing__true.golden

@@ -0,0 +1,2 @@
+> {"jsonrpc":"2.0","id":1,"method":"eth_syncing","params":[]}
+< {"jsonrpc":"2.0","id":1,"result":{"currentBlock":"0x3cf522","healedBytecodeBytes":"0x0","healedBytecodes":"0x0","healedTrienodes":"0x0","healingBytecode":"0x0","healingTrienodes":"0x0","highestBlock":"0x3e0e41","startingBlock":"0x3cbed5","syncedAccountBytes":"0x0","syncedAccounts":"0x0","syncedBytecodeBytes":"0x0","syncedBytecodes":"0x0","syncedStorage":"0x0","syncedStorageBytes":"0x0"}}