Feat/OPDATA-5851 truflation (#4749)

* OPDATA-5851 truflation EA initial commit

* OPDATA-5851 truflation EA initial commit - 2

* remove unused generated file

* add changeset

* add test and update error message

---------

Co-authored-by: app-token-issuer-data-feeds[bot] <134377064+app-token-issuer-data-feeds[bot]@users.noreply.github.com>

Author: mmcallister-cll

.changeset/chubby-aliens-follow.md

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+---
+'@chainlink/truflation-adapter': major
+---
+
+Truflation initial release

.pnp.cjs

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+# Chainlink External Adapter for truflation
+
+This README will be generated automatically when code is merged to `main`. If you would like to generate a preview of the README, please run `yarn generate:readme truflation`.

packages/sources/truflation/CHANGELOG.md

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+{
+  "name": "@chainlink/truflation-adapter",
+  "version": "0.0.0",
+  "description": "Chainlink truflation adapter.",
+  "keywords": [
+    "Chainlink",
+    "LINK",
+    "blockchain",
+    "oracle",
+    "truflation"
+  ],
+  "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": "^29.5.14",
+    "@types/node": "22.14.1",
+    "nock": "13.5.6",
+    "typescript": "5.8.3"
+  },
+  "dependencies": {
+    "@chainlink/external-adapter-framework": "2.13.1",
+    "tslib": "2.4.1"
+  }
+}

packages/sources/truflation/README.md

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+import { AdapterConfig } from '@chainlink/external-adapter-framework/config'
+
+export const config = new AdapterConfig({
+  API_KEY: {
+    description: 'An API key for Data Provider',
+    type: 'string',
+    required: true,
+    sensitive: true,
+  },
+  API_ENDPOINT: {
+    description: 'An API endpoint for Data Provider',
+    type: 'string',
+    default:
+      'https://api.truflation.com/api/v1/feed/truflation/macro-data-us/truflation_us_cpi_frozen_index',
+  },
+})

packages/sources/truflation/package.json

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+import { AdapterEndpoint } from '@chainlink/external-adapter-framework/adapter'
+import { InputParameters } from '@chainlink/external-adapter-framework/validation'
+import { config } from '../config'
+import { httpTransport } from '../transport/cpi'
+
+export const inputParameters = new InputParameters({})
+
+export type BaseEndpointTypes = {
+  Parameters: typeof inputParameters.definition
+  Response: {
+    Result: number
+    Data: {
+      date: string
+      cpi: number
+    }
+  }
+  Settings: typeof config.settings
+}
+
+export const endpoint = new AdapterEndpoint({
+  name: 'cpi',
+  transport: httpTransport,
+  inputParameters,
+})

packages/sources/truflation/src/config/index.ts

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+export { endpoint as cpi } from './cpi'

packages/sources/truflation/src/endpoint/cpi.ts

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+import { expose, ServerInstance } from '@chainlink/external-adapter-framework'
+import { Adapter } from '@chainlink/external-adapter-framework/adapter'
+import { config } from './config'
+import { cpi } from './endpoint'
+
+export const adapter = new Adapter({
+  defaultEndpoint: cpi.name,
+  name: 'TRUFLATION',
+  config,
+  endpoints: [cpi],
+  rateLimiting: {
+    tiers: {
+      default: {
+        rateLimit1m: 6,
+      },
+    },
+  },
+})
+
+export const server = (): Promise<ServerInstance | undefined> => expose(adapter)

packages/sources/truflation/src/endpoint/index.ts

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+import {
+  HttpTransport,
+  HttpTransportConfig,
+} from '@chainlink/external-adapter-framework/transports'
+import { BaseEndpointTypes } from '../endpoint/cpi'
+
+export interface ResponseSchema {
+  index: string[] // dates as string
+  truflation_us_cpi_frozen_index: number[]
+  start_date: string
+}
+
+export type HttpTransportTypes = BaseEndpointTypes & {
+  Provider: {
+    RequestBody: never
+    ResponseBody: ResponseSchema
+  }
+}
+
+const transportConfig: HttpTransportConfig<HttpTransportTypes> = {
+  prepareRequests: (params, config) => {
+    return params.map((param) => {
+      return {
+        params: [param],
+        request: {
+          baseURL: config.API_ENDPOINT,
+          headers: {
+            Authorization: config.API_KEY,
+          },
+        },
+      }
+    })
+  },
+  parseResponse: (params, response) => {
+    const data = response.data
+    if (
+      !data?.index?.length ||
+      !data?.truflation_us_cpi_frozen_index?.length ||
+      data.index.length !== data.truflation_us_cpi_frozen_index.length
+    ) {
+      return params.map((param) => {
+        return {
+          params: param,
+          response: {
+            errorMessage: `Invalid data provider response: index and truflation_us_cpi_frozen_index arrays must contain data and have equal length`,
+            statusCode: 502,
+          },
+        }
+      })
+    }
+
+    const originalIndexArrayCopy = Array.from(data.index)
+    // filter response, .sort() sorts ascending by default
+    const sortedIndexArray = originalIndexArrayCopy.sort()
+    const latestDate = sortedIndexArray[sortedIndexArray.length - 1]
+    const mappedIndex = data.index.indexOf(latestDate)
+    const result = data.truflation_us_cpi_frozen_index[mappedIndex]
+
+    return params.map((param) => {
+      return {
+        params: param,
+        response: {
+          result,
+          data: {
+            date: latestDate,
+            cpi: result,
+          },
+        },
+      }
+    })
+  },
+}
+
+export class CpiTransport extends HttpTransport<HttpTransportTypes> {
+  constructor() {
+    super(transportConfig)
+  }
+}
+
+export const httpTransport = new CpiTransport()