Add @ens helper

packages/evmcrispr/src/modules/std/helpers/ens.ts

@@ -0,0 +1,36 @@
+import { createPublicClient, http } from "viem";
+
+import { mainnet } from "viem/chains";
+
+import type { HelperFunction } from "../../../types";
+import { ComparisonType, checkArgsLength } from "../../../utils";
+import type { Std } from "../Std";
+
+import { HelperFunctionError } from "../../../errors";
+
+const mainnetClient = createPublicClient({
+  chain: mainnet,
+  transport: http(),
+});
+
+function _ens(name: string) {
+  return mainnetClient.getEnsAddress({ name });
+}
+
+export const ens: HelperFunction<Std> = async (
+  _,
+  h,
+  { interpretNodes },
+): Promise<string> => {
+  checkArgsLength(h, {
+    type: ComparisonType.Equal,
+    minValue: 1,
+  });
+
+  const [name] = await interpretNodes(h.args);
+  const addr = await _ens(name);
+  if (!addr) {
+    throw new HelperFunctionError(h, `ENS name ${name} not found`);
+  }
+  return addr;
+};

packages/evmcrispr/src/modules/std/helpers/index.ts

@@ -1,6 +1,7 @@
 import type { HelperFunctions } from "../../../types";
 import type { Std } from "../Std";
 import { date } from "./date";
+import { ens } from "./ens";
 import { get } from "./get";
 import { id } from "./id";
 import { namehash } from "./namehash";
@@ -10,6 +11,7 @@ import { token, tokenAmount, tokenBalance } from "./token";
 
 export const helpers: HelperFunctions<Std> = {
   date,
+  ens,
   get,
   id,
   namehash,

packages/evmcrispr/test/modules/std/helpers/ens.test.ts

@@ -0,0 +1,58 @@
+import { expect } from "chai";
+import { viem } from "hardhat";
+
+import type { PublicClient } from "viem";
+
+import { NodeType } from "../../../../src/types";
+import { ComparisonType } from "../../../../src/utils";
+
+import {
+  itChecksInvalidArgsLength,
+  preparingExpression,
+} from "../../../test-helpers/cas11";
+import { expectThrowAsync } from "../../../test-helpers/expects";
+import { HelperFunctionError } from "../../../../src/errors";
+
+describe("Std > helpers > @ens(name)", () => {
+  let client: PublicClient;
+  const lazyClient = () => client;
+
+  before(async () => {
+    client = await viem.getPublicClient();
+  });
+
+  it("return the hashed value", async () => {
+    const [interpret] = await preparingExpression(
+      `@ens('vitalik.eth')`,
+      client,
+    );
+
+    expect(await interpret()).to.equals(
+      "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
+    );
+  });
+
+  it("should fail when ENS name not found", async () => {
+    const [interpret, h] = await preparingExpression(
+      `@ens('_notfound.eth')`,
+      client,
+    );
+    const error = new HelperFunctionError(
+      h,
+      "ENS name _notfound.eth not found",
+    );
+
+    await expectThrowAsync(async () => interpret(), error);
+  });
+
+  itChecksInvalidArgsLength(
+    NodeType.HelperFunctionExpression,
+    "@ens",
+    ["exampleValue"],
+    {
+      type: ComparisonType.Equal,
+      minValue: 1,
+    },
+    lazyClient,
+  );
+});