test: fix code coverage reporting

Author: mlaursen

jest.config.cjs jest.config.tsjest.config.cjs renamed to jest.config.ts

@@ -1,22 +1,32 @@
-/** @type {import('@jest/types').Config.InitialOptions} */
-module.exports = {
+import type { Config } from "jest";
+
+const config: Config = {
   testEnvironment: "jsdom",
   transform: {
-    "^.+\\.(t|j)sx?$": ["@swc/jest"],
+    "^.+\\.(t|j)sx?$": "@swc/jest",
   },
+  setupFilesAfterEnv: ["<rootDir>/testSetup/init.ts"],
   moduleNameMapper: {
     // https://github.com/microsoft/accessibility-insights-web/pull/5421#issuecomment-1109168149
     "^nanoid": require.resolve("nanoid"),
     "\\.scss$": "identity-obj-proxy",
   },
-  setupFilesAfterEnv: ["<rootDir>/testSetup/init.ts"],
-  collectCoverageFrom: [
-    "<rootDir>/src/**/*.{ts,tsx}",
-    "!<rootDir>/src/index.ts",
-  ],
+
+  testPathIgnorePatterns: ["/node_modules/", "/cypress/"],
+
   watchPlugins: [
     "jest-watch-typeahead/filename",
     "jest-watch-typeahead/testname",
   ],
-  testPathIgnorePatterns: ["/node_modules/", "/cypress/"],
+
+  // this is required to get the correct line coverage when using swc for some
+  // reason.
+  coverageProvider: "v8",
+
+  collectCoverageFrom: [
+    "<rootDir>/src/**/*.{ts,tsx}",
+    "!<rootDir>/src/index.ts",
+  ],
 };
+
+export default config;