Add Avalanche method spec with eth_baseFee

chains.yaml

@@ -494,6 +494,7 @@ chain-settings:
       label: Avalanche
       type: eth
       settings:
+        method-spec: "avalanche"
         expected-block-time: 2s
         allow-pruning-requirement: true
         options:

docs/method-specs.md

@@ -250,7 +250,7 @@ Grouped by the transports they declare:
 
 | `api-connectors` | Specs |
 | --- | --- |
-| `json-rpc`, `websocket` | `arbitrum`, `avail`, `cronos_zkevm`, `eth-json-rpc`, `fantom`, `filecoin`, `harmony_0`, `harmony_1`, `hyperliquid-eth`, `klaytn-json-rpc`, `linea`, `mantle`, `optimism`, `polkadot-json-rpc`, `polygon`, `polygon_zkevm`, `rootstock`, `scroll`, `sei`, `solana-json-rpc`, `viction`, `zk` |
+| `json-rpc`, `websocket` | `arbitrum`, `avail`, `avalanche`, `cronos_zkevm`, `eth-json-rpc`, `fantom`, `filecoin`, `harmony_0`, `harmony_1`, `hyperliquid-eth`, `klaytn-json-rpc`, `linea`, `mantle`, `optimism`, `polkadot-json-rpc`, `polygon`, `polygon_zkevm`, `rootstock`, `scroll`, `sei`, `solana-json-rpc`, `viction`, `zk` |
 | `json-rpc` | `algorand-json-rpc`, `aztec`, `bitcoin-json-rpc`, `celestia-json-rpc`, `near-json-rpc`, `starknet-json-rpc`, `stellar-json-rpc`, `tron-json-rpc` |
 | `websocket` | `eth-websocket`, `klaytn-websocket`, `polkadot-websocket`, `solana-websocket` |
 | `tendermint` | `cosmos-tendermint` |

pkg/methods/methods_spec_test.go

@@ -427,6 +427,23 @@ func TestAlgorandSpecLoads(t *testing.T) {
 	assert.Equal(t, []string{"12345"}, params)
 }
 
+func TestAvalancheSpecLoads(t *testing.T) {
+	err := specs.NewMethodSpecLoader().Load()
+	assert.NoError(t, err)
+
+	// avalanche's own extension method is available...
+	spec := specs.GetSpecMethod("avalanche", "eth_baseFee")
+	assert.NotNil(t, spec)
+	assert.False(t, spec.IsCacheable())
+
+	// ...on top of every method the imported `eth` spec already provides.
+	spec = specs.GetSpecMethod("avalanche", "eth_blockNumber")
+	assert.NotNil(t, spec)
+
+	spec = specs.GetSpecMethod("avalanche", "ftm_effectiveBaseFee")
+	assert.Nil(t, spec)
+}
+
 func TestLoadSpecGrpcDefaults(t *testing.T) {
 	err := specs.NewMethodSpecLoaderWithFs(os.DirFS("test_specs/grpc")).Load()
 	assert.NoError(t, err)

pkg/methods/specs/avalanche.json

@@ -0,0 +1,27 @@
+{
+  "openrpc": "1.0.0",
+  "info": {
+    "title": "Avalanche C-Chain JSON-RPC methods",
+    "version": "1.0.0"
+  },
+  "spec": {
+    "name": "avalanche",
+    "api-connectors": [
+      "json-rpc",
+      "websocket"
+    ],
+    "type": "plain"
+  },
+  "spec-imports": [
+    "eth"
+  ],
+  "methods": [
+    {
+      "name": "eth_baseFee",
+      "settings": {
+        "cacheable": false
+      },
+      "params": []
+    }
+  ]
+}