feat: chain type (#42)

# 🤖 Linear

Closes ZKS-79

## Description

- Add `chainType` logic to `L1MetricsService`
- extract diamond proxy fetching logic into a function called
`fetchDiamondProxyAddress`

libs/metrics/src/exceptions/index.ts

@@ -1,2 +1,3 @@
 export * from "./invalidChainId.exception";
 export * from "./l1MetricsService.exception";
+export * from "./invalidChainType.exception";

libs/metrics/src/exceptions/invalidChainType.exception.ts

@@ -0,0 +1,11 @@
+import { Chains } from "@zkchainhub/shared";
+
+export class InvalidChainType extends Error {
+    constructor(index: number) {
+        super(`Current supported types are [${Chains.join(
+            ", ",
+        )}], but received index ${index}. Verify if supported chains are consistent with https://github.com/matter-labs/era-contracts/blob/8a70bbbc48125f5bde6189b4e3c6a3ee79631678/l1-contracts/contracts/state-transition/chain-deps/ZkSyncHyperchainStorage.sol#L39
+`);
+        this.name = "InvalidChainType";
+    }
+}

libs/metrics/src/l1/l1MetricsService.ts

@@ -12,12 +12,23 @@ import {
     zeroAddress,
 } from "viem";
 
-import { InvalidChainId, L1MetricsServiceException } from "@zkchainhub/metrics/exceptions";
+import {
+    InvalidChainId,
+    InvalidChainType,
+    L1MetricsServiceException,
+} from "@zkchainhub/metrics/exceptions";
 import { bridgeHubAbi, diamondProxyAbi, sharedBridgeAbi } from "@zkchainhub/metrics/l1/abis";
 import { AssetTvl, GasInfo } from "@zkchainhub/metrics/types";
 import { IPricingService, PRICING_PROVIDER } from "@zkchainhub/pricing";
 import { EvmProviderService } from "@zkchainhub/providers";
-import { BatchesInfo, ChainId, L1_CONTRACTS, vitalikAddress } from "@zkchainhub/shared";
+import {
+    BatchesInfo,
+    ChainId,
+    Chains,
+    ChainType,
+    L1_CONTRACTS,
+    vitalikAddress,
+} from "@zkchainhub/shared";
 import { ETH_TOKEN_ADDRESS } from "@zkchainhub/shared/constants";
 import {
     erc20Tokens,
@@ -148,22 +159,8 @@ export class L1MetricsService {
      * @param chainId - The chain id for which to get the batches info
      * @returns commits, verified and executed batches
      */
-    async getBatchesInfo(chainId: ChainId): Promise<BatchesInfo> {
-        let diamondProxyAddress: Address | undefined = this.diamondContracts.get(chainId);
-
-        if (!diamondProxyAddress) {
-            diamondProxyAddress = await this.evmProviderService.readContract(
-                this.bridgeHub.address,
-                this.bridgeHub.abi,
-                "getHyperchain",
-                [chainId],
-            );
-            if (diamondProxyAddress == zeroAddress) {
-                throw new InvalidChainId(`Chain ID ${chainId} doesn't exist on the ecosystem`);
-            }
-            this.diamondContracts.set(chainId, diamondProxyAddress);
-        }
-
+    async getBatchesInfo(chainId: bigint): Promise<BatchesInfo> {
+        const diamondProxyAddress = await this.fetchDiamondProxyAddress(chainId);
         const [commited, verified, executed] = await this.evmProviderService.multicall({
             contracts: [
                 {
@@ -237,9 +234,42 @@ export class L1MetricsService {
         return { ethBalance: balances[addresses.length]!, addressesBalance: balances.slice(0, -1) };
     }
 
-    //TODO: Implement chainType.
-    async chainType(_chainId: ChainId): Promise<"validium" | "rollup"> {
-        return "rollup";
+    async chainType(chainId: ChainId): Promise<ChainType> {
+        const diamondProxyAddress = await this.fetchDiamondProxyAddress(chainId);
+        const chainTypeIndex = await this.evmProviderService.readContract(
+            diamondProxyAddress,
+            diamondProxyAbi,
+            "getPubdataPricingMode",
+            [],
+        );
+        const chainType = Chains[chainTypeIndex];
+        if (!chainType) {
+            throw new InvalidChainType(chainTypeIndex);
+        }
+        return chainType;
+    }
+
+    /**
+     * Fetches the diamond proxy address for the given chain id and caches it for future use.
+     * @param chainId - The chain id for which to fetch the diamond proxy address.
+     * @returns Diamond proxy address.
+     */
+    private async fetchDiamondProxyAddress(chainId: ChainId): Promise<Address> {
+        let diamondProxyAddress: Address | undefined = this.diamondContracts.get(chainId);
+
+        if (!diamondProxyAddress) {
+            diamondProxyAddress = await this.evmProviderService.readContract(
+                this.bridgeHub.address,
+                this.bridgeHub.abi,
+                "getHyperchain",
+                [chainId],
+            );
+            if (diamondProxyAddress == zeroAddress) {
+                throw new InvalidChainId(`Chain ID ${chainId} doesn't exist on the ecosystem`);
+            }
+            this.diamondContracts.set(chainId, diamondProxyAddress);
+        }
+        return diamondProxyAddress;
     }
 
     /**

libs/metrics/test/unit/l1/l1MetricsService.spec.ts

@@ -4,12 +4,22 @@ import { Test, TestingModule } from "@nestjs/testing";
 import { WINSTON_MODULE_PROVIDER } from "nest-winston";
 import { encodeFunctionData, erc20Abi, parseEther, zeroAddress } from "viem";
 
-import { InvalidChainId, L1MetricsServiceException } from "@zkchainhub/metrics/exceptions";
+import {
+    InvalidChainId,
+    InvalidChainType,
+    L1MetricsServiceException,
+} from "@zkchainhub/metrics/exceptions";
 import { L1MetricsService } from "@zkchainhub/metrics/l1/";
 import { bridgeHubAbi, diamondProxyAbi, sharedBridgeAbi } from "@zkchainhub/metrics/l1/abis";
 import { IPricingService, PRICING_PROVIDER } from "@zkchainhub/pricing";
 import { EvmProviderService } from "@zkchainhub/providers";
-import { BatchesInfo, ETH_TOKEN_ADDRESS, L1_CONTRACTS, vitalikAddress } from "@zkchainhub/shared";
+import {
+    BatchesInfo,
+    ChainType,
+    ETH_TOKEN_ADDRESS,
+    L1_CONTRACTS,
+    vitalikAddress,
+} from "@zkchainhub/shared";
 import { nativeToken, WETH } from "@zkchainhub/shared/tokens/tokens";
 
 // Mock implementations of the dependencies
@@ -361,6 +371,47 @@ describe("L1MetricsService", () => {
         });
     });
 
+    describe("fetchDiamondProxyAddress", () => {
+        it("returns address if already exists in the map", async () => {
+            const chainId = 324n; // this is ZKsyncEra chain id
+            const mockedDiamondProxyAddress = "0x1234567890123456789012345678901234567890";
+            l1MetricsService["diamondContracts"].clear();
+            l1MetricsService["diamondContracts"].set(chainId, mockedDiamondProxyAddress);
+
+            const readContractSpy = jest.spyOn(mockEvmProviderService, "readContract");
+            const result = await l1MetricsService["fetchDiamondProxyAddress"](chainId);
+
+            expect(result).toEqual(mockedDiamondProxyAddress);
+            expect(l1MetricsService["diamondContracts"].get(chainId)).toEqual(
+                mockedDiamondProxyAddress,
+            );
+            expect(readContractSpy).toHaveBeenCalledTimes(0);
+        });
+        it("fetches and sets diamond proxy if chainId doesn't exists on map", async () => {
+            const chainId = 324n; // this is ZKsyncEra chain id
+            const mockedDiamondProxyAddress = "0x1234567890123456789012345678901234567890";
+
+            l1MetricsService["diamondContracts"].clear();
+
+            jest.spyOn(mockEvmProviderService, "readContract").mockResolvedValue(
+                mockedDiamondProxyAddress,
+            );
+            const result = await l1MetricsService["fetchDiamondProxyAddress"](chainId);
+
+            expect(result).toEqual(mockedDiamondProxyAddress);
+
+            expect(l1MetricsService["diamondContracts"].get(chainId)).toEqual(
+                mockedDiamondProxyAddress,
+            );
+            expect(mockEvmProviderService.readContract).toHaveBeenCalledWith(
+                l1MetricsService["bridgeHub"].address,
+                l1MetricsService["bridgeHub"].abi,
+                "getHyperchain",
+                [BigInt(chainId)],
+            );
+        });
+    });
+
     describe("tvl", () => {
         it("return the TVL for chain id", async () => {
             const mockBalances = [60_841_657_140641n, 135_63005559n, 123_803_824374847279970609n]; // Mocked balances
@@ -460,9 +511,59 @@ describe("L1MetricsService", () => {
     });
 
     describe("chainType", () => {
-        it("return chainType", async () => {
-            const result = await l1MetricsService.chainType(1n);
-            expect(result).toBe("rollup");
+        it("returns chainType", async () => {
+            const chainId = 324n; // this is ZKsyncEra chain id
+            const mockedDiamondProxyAddress = "0x1234567890123456789012345678901234567890";
+
+            l1MetricsService["diamondContracts"].set(chainId, mockedDiamondProxyAddress);
+            const mockChainType: ChainType = "Rollup";
+
+            const readContractSpy = jest
+                .spyOn(mockEvmProviderService, "readContract")
+                .mockResolvedValue(0);
+
+            const result = await l1MetricsService.chainType(chainId);
+
+            expect(result).toEqual(mockChainType);
+            expect(readContractSpy).toHaveBeenCalledWith(
+                mockedDiamondProxyAddress,
+                diamondProxyAbi,
+                "getPubdataPricingMode",
+                [],
+            );
+        });
+        it("returns chainType", async () => {
+            const chainId = 324n; // this is ZKsyncEra chain id
+            const mockedDiamondProxyAddress = "0x1234567890123456789012345678901234567890";
+
+            l1MetricsService["diamondContracts"].set(chainId, mockedDiamondProxyAddress);
+            const mockChainType: ChainType = "Validium";
+
+            const readContractSpy = jest
+                .spyOn(mockEvmProviderService, "readContract")
+                .mockResolvedValue(1);
+
+            const result = await l1MetricsService.chainType(chainId);
+
+            expect(result).toEqual(mockChainType);
+            expect(readContractSpy).toHaveBeenCalledWith(
+                mockedDiamondProxyAddress,
+                diamondProxyAbi,
+                "getPubdataPricingMode",
+                [],
+            );
+        });
+        it("throws if blockchain returns an out of bounds index", async () => {
+            const chainId = 324n; // this is ZKsyncEra chain id
+            const mockedDiamondProxyAddress = "0x1234567890123456789012345678901234567890";
+
+            l1MetricsService["diamondContracts"].set(chainId, mockedDiamondProxyAddress);
+
+            jest.spyOn(mockEvmProviderService, "readContract").mockResolvedValue(100);
+
+            await expect(l1MetricsService.chainType(chainId)).rejects.toThrowError(
+                InvalidChainType,
+            );
         });
     });
 

libs/shared/src/types/rollup.type.ts

@@ -1,3 +1,4 @@
+// Chains should not change since it is a direct mapping of https://github.com/matter-labs/era-contracts/blob/8a70bbbc48125f5bde6189b4e3c6a3ee79631678/l1-contracts/contracts/state-transition/chain-deps/ZkSyncHyperchainStorage.sol#L39
 /**
  * An array of supported chain types.
  * @readonly