Migrate to ESM (#291)

* Migrate to ESM

* Migrate to eslint flat config

eslint.config.js

@@ -0,0 +1,21 @@
+// @ts-check
+
+import eslint from '@eslint/js'
+import jest from 'eslint-plugin-jest'
+import tseslint from 'typescript-eslint'
+
+export default tseslint.config(
+  {
+    ignores: ['.git/', 'node_modules/', 'dist/', 'eslint.config.js'],
+  },
+  eslint.configs.recommended,
+  ...tseslint.configs.recommendedTypeChecked,
+  jest.configs['flat/recommended'],
+  {
+    languageOptions: {
+      parserOptions: {
+        project: true,
+      },
+    },
+  },
+)

jest.config.js

@@ -1,7 +1,9 @@
-module.exports = {
-  preset: 'ts-jest',
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+export default {
+  preset: 'ts-jest/presets/default-esm',
   clearMocks: true,
-  testEnvironment: 'node',
-  testMatch: ['**/*.test.ts'],
-  verbose: true
+  // https://kulshekhar.github.io/ts-jest/docs/guides/esm-support/
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1',
+  },
 }

package.json

@@ -2,10 +2,11 @@
   "private": true,
   "scripts": {
     "format": "prettier --write **/*.ts",
-    "lint": "eslint **/*.ts",
+    "lint": "eslint .",
     "build": "ncc build --source-map --license licenses.txt src/main.ts",
     "test": "jest"
   },
+  "type": "module",
   "dependencies": {
     "@actions/core": "1.10.1",
     "@actions/glob": "0.4.0",
@@ -15,14 +16,13 @@
     "@tsconfig/node20": "20.1.4",
     "@types/jest": "29.5.12",
     "@types/node": "20.12.5",
-    "@typescript-eslint/eslint-plugin": "7.5.0",
-    "@typescript-eslint/parser": "7.5.0",
     "@vercel/ncc": "0.38.1",
     "eslint": "9.0.0",
     "eslint-plugin-jest": "28.2.0",
     "jest": "29.7.0",
     "prettier": "3.2.5",
     "ts-jest": "29.1.2",
-    "typescript": "5.4.4"
+    "typescript": "5.4.4",
+    "typescript-eslint": "^7.6.0"
   }
 }

src/csv.ts

@@ -3,15 +3,14 @@ import * as fs from 'fs/promises'
 import * as glob from '@actions/glob'
 import { v1 } from '@datadog/datadog-api-client'
 import assert from 'assert'
-import { Series } from '@datadog/datadog-api-client/dist/packages/datadog-api-client-v1'
 
 export type MetricsFromCsvInputs = {
   metricsCsvPath: string
 }
 
 export const sendMetricsFromCsv = async (api: v1.MetricsApi, inputs: MetricsFromCsvInputs) => {
   const unixTime = Date.now() / 1000
-  const series: Series[] = []
+  const series: v1.Series[] = []
 
   const csvGrobber = await glob.create(inputs.metricsCsvPath, { matchDirectories: false })
   for await (const csvPath of csvGrobber.globGenerator()) {
@@ -24,8 +23,8 @@ export const sendMetricsFromCsv = async (api: v1.MetricsApi, inputs: MetricsFrom
   core.info(`Sent the metrics: ${String(metricsResponse.status)}`)
 }
 
-export const parseMetricsCsv = async (csvPath: string, unixTime: number): Promise<Series[]> => {
-  const series: Series[] = []
+export const parseMetricsCsv = async (csvPath: string, unixTime: number): Promise<v1.Series[]> => {
+  const series: v1.Series[] = []
   const f = await fs.open(csvPath, 'r')
   for await (const line of f.readLines()) {
     const columns = line.split(',')