feat: Enable PathDB config (#1244)

Author: alarso16

plugin/evm/config/config.md

@@ -255,7 +255,7 @@ Configuration is provided as a JSON object. All fields are optional unless other
 
 ## Database Configuration
 
-> **WARNING**: `firewood` scheme is untested in production. To use `firewood`, you must also set the following config options:
+> **WARNING**: `firewood` and `path` schemes are untested in production. Using `path` is strongly discouraged. To use `firewood`, you must also set the following config options:
 >
 > - `pruning-enabled: true` (enabled by default)
 > - `state-sync-enabled: false`
@@ -266,7 +266,7 @@ Failing to set these options will result in errors on VM initialization. Additio
 | Option | Type | Description | Default |
 |--------|------|-------------|---------|
 | `inspect-database` | bool | Inspect database on startup | `false` |
-| `state-scheme` | string |  EXPERIMENTAL: specifies the database scheme to store state data; can be one of `hash` or `firewood` | `hash` | 
+| `state-scheme` | string |  EXPERIMENTAL: specifies the database scheme to store state data; can be one of `hash`, `firewood`, or `path` | `hash` | 
 
 ## Transaction Indexing
 

plugin/evm/vm.go

@@ -144,7 +144,6 @@ var (
 	errFirewoodSnapshotCacheDisabled     = errors.New("snapshot cache must be disabled for Firewood")
 	errFirewoodOfflinePruningUnsupported = errors.New("offline pruning is not supported for Firewood")
 	errFirewoodStateSyncUnsupported      = errors.New("state sync is not yet supported for Firewood")
-	errPathStateUnsupported              = errors.New("path state scheme is not supported")
 )
 
 var originalStderr *os.File
@@ -410,8 +409,7 @@ func (vm *VM) Initialize(
 		}
 	}
 	if vm.ethConfig.StateScheme == rawdb.PathScheme {
-		log.Error("Path state scheme is not supported. Please use HashDB or Firewood state schemes instead")
-		return errPathStateUnsupported
+		log.Warn("Path state scheme is not supported. Please use HashDB or Firewood state schemes instead")
 	}
 
 	// Create directory for offline pruning

plugin/evm/vm_test.go

@@ -28,6 +28,7 @@ import (
 	"github.com/ava-labs/avalanchego/vms/platformvm/warp/payload"
 	"github.com/ava-labs/libevm/common"
 	"github.com/ava-labs/libevm/common/math"
+	"github.com/ava-labs/libevm/core/rawdb"
 	"github.com/ava-labs/libevm/core/types"
 	"github.com/ava-labs/libevm/crypto"
 	"github.com/ava-labs/libevm/log"
@@ -45,6 +46,7 @@ import (
 	"github.com/ava-labs/coreth/params"
 	"github.com/ava-labs/coreth/params/paramstest"
 	"github.com/ava-labs/coreth/plugin/evm/customheader"
+	"github.com/ava-labs/coreth/plugin/evm/customrawdb"
 	"github.com/ava-labs/coreth/plugin/evm/customtypes"
 	"github.com/ava-labs/coreth/plugin/evm/extension"
 	"github.com/ava-labs/coreth/plugin/evm/message"
@@ -198,7 +200,8 @@ func testVMUpgrades(t *testing.T, scheme string) {
 }
 
 func TestBuildEthTxBlock(t *testing.T) {
-	for _, scheme := range vmtest.Schemes {
+	// This test is done for all schemes to ensure the VM can be started with any scheme.
+	for _, scheme := range []string{rawdb.HashScheme, rawdb.PathScheme, customrawdb.FirewoodScheme} {
 		t.Run(scheme, func(t *testing.T) {
 			testBuildEthTxBlock(t, scheme)
 		})