Update typechecking and testing config

* Make typechecking stricter, and have it apply for the `test/`
  directory
* Only run tests with `*.test*` in their name, so that Jest doesn't
  try to run the `dataset.ts` file

jest.config.js

@@ -1,6 +1,12 @@
+/*
+ * Unless explicitly stated otherwise all files in this repository are licensed
+ * under the Apache 2.0 license (see LICENSE).
+ * This product includes software developed at Datadog (https://www.datadoghq.com/).
+ * Copyright 2020 Datadog, Inc.
+ */
+
 module.exports = {
     preset: 'ts-jest',
     testEnvironment: 'node',
-    testMatch: ['<rootDir>/test/**/*.[jt]s']
+    testMatch: ['<rootDir>/test/**/*.test.[jt]s']
 };
-

prettier.config.js

@@ -1,3 +1,10 @@
+/*
+ * Unless explicitly stated otherwise all files in this repository are licensed
+ * under the Apache 2.0 license (see LICENSE).
+ * This product includes software developed at Datadog (https://www.datadoghq.com/).
+ * Copyright 2020 Datadog, Inc.
+ */
+
 module.exports = {
     printWidth: 80,
     tabWidth: 4,

tsconfig.json

@@ -4,11 +4,17 @@
     "module": "commonjs",
     "declaration": true,
     "strict": true,
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "strictFunctionTypes": true,
+    "noImplicitThis": true,
+    "alwaysStrict": true,
+    "noFallthroughCasesInSwitch": true,
     "esModuleInterop": true,
     "forceConsistentCasingInFileNames": true,
     "outDir": "./dist"
   },
   "include": [
-    "./src"
+    "./src", "./test"
   ]
 }