Added new view-function-multi-chain EA (#3217)

* add view-function-multi-chain EA

* update test-payload

.changeset/dry-laws-hang.md

@@ -0,0 +1,5 @@
+---
+'@chainlink/view-function-multi-chain-adapter': major
+---
+
+Initial version of the EA

packages/scripts/src/generate-readme/readmeBlacklist.json

@@ -57,6 +57,7 @@
     "the-graph",
     "token-allocation",
     "vesper",
+    "view-function-multi-chain",
     "xsushi-price"
   ]
 }

packages/sources/view-function-multi-chain/README.md

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+# VIEW_FUNCTION_MULTI_CHAIN
+
+![v3](https://img.shields.io/badge/framework%20version-v3-blueviolet)
+
+## Environment Variables
+
+| Required? |         Name          |                                        Description                                        |  Type  | Options | Default |
+| :-------: | :-------------------: | :---------------------------------------------------------------------------------------: | :----: | :-----: | :-----: |
+|    ✅     |  {NETWORK}\_RPC_URL   |           RPC url for a NETWORK. NETWORK is the value of `network` input param            | string |         |         |
+|    ✅     |  {NETWORK}\_CHAIN_ID  |           Chain id for a NETWORK. NETWORK is the value of `network` input param           | number |         |         |
+|           | BACKGROUND_EXECUTE_MS | The amount of time the background execute should sleep before performing the next request | number |         | `10000` |
+
+---
+
+## Data Provider Rate Limits
+
+There are no rate limits for this adapter.
+
+---
+
+## Input Parameters
+
+| Required? |   Name   |     Description     |  Type  |            Options             |  Default   |
+| :-------: | :------: | :-----------------: | :----: | :----------------------------: | :--------: |
+|           | endpoint | The endpoint to use | string | [function](#function-endpoint) | `function` |
+
+## Function Endpoint
+
+`function` is the only supported name for this endpoint.
+
+### Input Params
+
+| Required? |    Name     |  Aliases   |                                                                         Description                                                                         |   Type   | Options | Default | Depends On | Not Valid With |
+| :-------: | :---------: | :--------: | :---------------------------------------------------------------------------------------------------------------------------------------------------------: | :------: | :-----: | :-----: | :--------: | :------------: |
+|    ✅     |  signature  | `function` | Function signature. Should be formatted as [human readable ABI](https://docs.ethers.io/v5/single-page/#/v5/getting-started/-%23-getting-started--contracts) |  string  |         |         |            |                |
+|    ✅     |   address   | `contract` |                                                                   Address of the contract                                                                   |  string  |         |         |            |                |
+|           | inputParams |            |                                                            Array of function parameters in order                                                            | string[] |         |         |            |                |
+|    ✅     |   network   |            |                                                                      RPC network name                                                                       |  string  |         |         |            |                |
+
+### Example
+
+Request:
+
+```json
+{
+  "data": {
+    "endpoint": "function",
+    "signature": "function latestAnswer() view returns (int256)",
+    "address": "0x779877A7B0D9E8603169DdbD7836e478b4624789",
+    "network": "ETHEREUM_GOERLI"
+  }
+}
+```
+
+---
+
+MIT License

packages/sources/view-function-multi-chain/package.json

@@ -0,0 +1,41 @@
+{
+  "name": "@chainlink/view-function-multi-chain-adapter",
+  "version": "0.0.0",
+  "description": "Chainlink view-function-multi-chain adapter.",
+  "keywords": [
+    "Chainlink",
+    "LINK",
+    "blockchain",
+    "oracle",
+    "view-function-multi-chain"
+  ],
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "repository": {
+    "url": "https://github.com/smartcontractkit/external-adapters-js",
+    "type": "git"
+  },
+  "license": "MIT",
+  "scripts": {
+    "clean": "rm -rf dist && rm -f tsconfig.tsbuildinfo",
+    "prepack": "yarn build",
+    "build": "tsc -b",
+    "server": "node -e 'require(\"./index.js\").server()'",
+    "server:dist": "node -e 'require(\"./dist/index.js\").server()'",
+    "start": "yarn server:dist"
+  },
+  "devDependencies": {
+    "@types/jest": "27.5.2",
+    "@types/node": "16.11.68",
+    "nock": "13.2.9",
+    "typescript": "5.0.4"
+  },
+  "dependencies": {
+    "@chainlink/external-adapter-framework": "0.33.4",
+    "ethers": "^5.4.6",
+    "tslib": "2.4.1"
+  }
+}

packages/sources/view-function-multi-chain/src/config/index.ts

@@ -0,0 +1,10 @@
+import { AdapterConfig } from '@chainlink/external-adapter-framework/config'
+
+export const config = new AdapterConfig({
+  BACKGROUND_EXECUTE_MS: {
+    description:
+      'The amount of time the background execute should sleep before performing the next request',
+    type: 'number',
+    default: 10_000,
+  },
+})

packages/sources/view-function-multi-chain/src/endpoint/function.ts

@@ -0,0 +1,47 @@
+import { AdapterEndpoint } from '@chainlink/external-adapter-framework/adapter'
+import { InputParameters } from '@chainlink/external-adapter-framework/validation'
+import { config } from '../config'
+import { multiChainFunctionTransport } from '../transport/function'
+
+export const inputParameters = new InputParameters({
+  signature: {
+    type: 'string',
+    aliases: ['function'],
+    required: true,
+    description:
+      'Function signature. Should be formatted as [human readable ABI](https://docs.ethers.io/v5/single-page/#/v5/getting-started/-%23-getting-started--contracts)',
+  },
+  address: {
+    aliases: ['contract'],
+    required: true,
+    description: 'Address of the contract',
+    type: 'string',
+  },
+  inputParams: {
+    array: true,
+    description: 'Array of function parameters in order',
+    type: 'string',
+  },
+  network: {
+    required: true,
+    description: 'RPC network name',
+    type: 'string',
+  },
+})
+
+export type BaseEndpointTypes = {
+  Parameters: typeof inputParameters.definition
+  Response: {
+    Data: {
+      result: string
+    }
+    Result: string
+  }
+  Settings: typeof config.settings
+}
+
+export const endpoint = new AdapterEndpoint({
+  name: 'function',
+  transport: multiChainFunctionTransport,
+  inputParameters,
+})

packages/sources/view-function-multi-chain/src/endpoint/index.ts

@@ -0,0 +1 @@
+export { endpoint as functionEndpoint } from './function'

packages/sources/view-function-multi-chain/src/index.ts

@@ -0,0 +1,13 @@
+import { expose, ServerInstance } from '@chainlink/external-adapter-framework'
+import { Adapter } from '@chainlink/external-adapter-framework/adapter'
+import { config } from './config'
+import { functionEndpoint } from './endpoint'
+
+export const adapter = new Adapter({
+  defaultEndpoint: functionEndpoint.name,
+  name: 'VIEW_FUNCTION_MULTI_CHAIN',
+  config,
+  endpoints: [functionEndpoint],
+})
+
+export const server = (): Promise<ServerInstance | undefined> => expose(adapter)

packages/sources/view-function-multi-chain/src/transport/function.ts

@@ -0,0 +1,110 @@
+import { TransportDependencies } from '@chainlink/external-adapter-framework/transports'
+import { AdapterResponse, makeLogger, sleep } from '@chainlink/external-adapter-framework/util'
+import { SubscriptionTransport } from '@chainlink/external-adapter-framework/transports/abstract/subscription'
+import { EndpointContext } from '@chainlink/external-adapter-framework/adapter'
+import { ethers, utils } from 'ethers'
+import { BaseEndpointTypes, inputParameters } from '../endpoint/function'
+import { AdapterInputError } from '@chainlink/external-adapter-framework/validation/error'
+
+const logger = makeLogger('View Function Multi Chain')
+
+export type MultiChainFunctionTransportTypes = BaseEndpointTypes
+
+type RequestParams = typeof inputParameters.validated
+
+export class MultiChainFunctionTransport extends SubscriptionTransport<MultiChainFunctionTransportTypes> {
+  providers: Record<string, ethers.providers.JsonRpcProvider> = {}
+
+  async initialize(
+    dependencies: TransportDependencies<MultiChainFunctionTransportTypes>,
+    adapterSettings: MultiChainFunctionTransportTypes['Settings'],
+    endpointName: string,
+    transportName: string,
+  ): Promise<void> {
+    await super.initialize(dependencies, adapterSettings, endpointName, transportName)
+  }
+
+  async backgroundHandler(
+    context: EndpointContext<MultiChainFunctionTransportTypes>,
+    entries: RequestParams[],
+  ) {
+    await Promise.all(entries.map(async (param) => this.handleRequest(param)))
+    await sleep(context.adapterSettings.BACKGROUND_EXECUTE_MS)
+  }
+
+  async handleRequest(param: RequestParams) {
+    let response: AdapterResponse<MultiChainFunctionTransportTypes['Response']>
+    try {
+      response = await this._handleRequest(param)
+    } catch (e: unknown) {
+      const errorMessage = e instanceof Error ? e.message : 'Unknown error occurred'
+      logger.error(e, errorMessage)
+      response = {
+        statusCode: (e as AdapterInputError)?.statusCode || 502,
+        errorMessage,
+        timestamps: {
+          providerDataRequestedUnixMs: 0,
+          providerDataReceivedUnixMs: 0,
+          providerIndicatedTimeUnixMs: undefined,
+        },
+      }
+    }
+    await this.responseCache.write(this.name, [{ params: param, response }])
+  }
+
+  async _handleRequest(
+    param: RequestParams,
+  ): Promise<AdapterResponse<MultiChainFunctionTransportTypes['Response']>> {
+    const { address, signature, inputParams, network } = param
+
+    const networkName = network.toUpperCase()
+    const networkEnvName = `${networkName}_RPC_URL`
+    const chainIdEnvName = `${networkName}_CHAIN_ID`
+
+    const rpcUrl = process.env[networkEnvName]
+    const chainId = Number(process.env[chainIdEnvName])
+
+    if (!rpcUrl || isNaN(chainId)) {
+      throw new AdapterInputError({
+        statusCode: 400,
+        message: `Missing '${networkEnvName}' or '${chainIdEnvName}' environment variables.`,
+      })
+    }
+
+    if (!this.providers[networkName]) {
+      this.providers[networkName] = new ethers.providers.JsonRpcProvider(rpcUrl, chainId)
+    }
+
+    const iface = new utils.Interface([signature])
+    const fnName = iface.functions[Object.keys(iface.functions)[0]].name
+
+    const encoded = iface.encodeFunctionData(fnName, [...(inputParams || [])])
+
+    const providerDataRequestedUnixMs = Date.now()
+    const result = await this.providers[networkName].call({
+      to: address,
+      data: encoded,
+    })
+
+    return {
+      data: {
+        result,
+      },
+      statusCode: 200,
+      result,
+      timestamps: {
+        providerDataRequestedUnixMs,
+        providerDataReceivedUnixMs: Date.now(),
+        providerIndicatedTimeUnixMs: undefined,
+      },
+    }
+  }
+
+  getSubscriptionTtlFromConfig(
+    adapterSettings: MultiChainFunctionTransportTypes['Settings'],
+  ): number {
+    return adapterSettings.WARMUP_SUBSCRIPTION_TTL
+  }
+}
+
+export const multiChainFunctionTransport = new MultiChainFunctionTransport()

packages/sources/view-function-multi-chain/test-payload.json

@@ -0,0 +1,7 @@
+{
+ "requests": [{
+  "contract": "0x2c1d072e956AFFC0D435Cb7AC38EF18d24d9127c",
+  "function": "function latestAnswer() view returns (int256)",
+  "network": "ETHEREUM_MAINNET"
+ }]
+}