feat(api-evm): resolve block tag parameter (#856)

* resolve block tag

* Empty commit

* style: resolve style guide violations

packages/api-evm/source/actions/eth-get-block-by-number.ts

@@ -2,6 +2,7 @@ import { inject, injectable } from "@mainsail/container";
 import { Contracts, Identifiers } from "@mainsail/contracts";
 
 import { BlockResource } from "../resources/index.js";
+import { resolveBlockTag } from "../utils/resolve-block-tag.js";
 
 @injectable()
 export class EthGetBlockByNumberAction implements Contracts.Api.RPC.Action {
@@ -26,8 +27,8 @@ export class EthGetBlockByNumberAction implements Contracts.Api.RPC.Action {
 		type: "array",
 	};
 
-	public async handle(parameters: [string, boolean]): Promise<object | null> {
-		const height = parameters[0].startsWith("0x") ? Number.parseInt(parameters[0]) : this.stateStore.getHeight();
+	public async handle(parameters: [string | Contracts.Crypto.BlockTag, boolean]): Promise<object | null> {
+		const height = await resolveBlockTag(this.stateStore, parameters[0]);
 		const transactionObject = parameters[1];
 
 		const block = await this.databaseService.getBlock(height);

packages/api-evm/source/utils/resolve-block-tag.ts

@@ -0,0 +1,21 @@
+import { Contracts } from "@mainsail/contracts";
+
+export const resolveBlockTag = async (
+	stateStore: Contracts.State.Store,
+	tag: string | Contracts.Crypto.BlockTag,
+): Promise<number> => {
+	if (tag.startsWith("0x")) {
+		return Number.parseInt(tag);
+	}
+
+	switch (tag as Contracts.Crypto.BlockTag) {
+		case "finalized":
+		case "latest":
+		case "safe": {
+			return stateStore.getHeight();
+		}
+		default: {
+			throw new Error("invalid blockTag:" + tag);
+		}
+	}
+};

packages/api-evm/source/validation/schemas.ts

@@ -5,7 +5,7 @@ export const schemas: Record<"blockTag", AnySchemaObject> = {
 		$id: "blockTag",
 		anyOf: [
 			{
-				enum: ["latest", "finalized", "safe"],
+				enum: ["latest", "safe", "finalized"],
 				type: "string",
 			},
 			{