Typecheck tests

Makefile

@@ -5,8 +5,8 @@ else
 	/ := /
 endif
 
-build: clean  # builds the production version
-	@node_modules$/.bin$/tsc -p .
+build: # builds the production version
+	@node_modules$/.bin$/tsc -p tsconfig-build.json
 
 clean:  # removes all build artifacts
 	@rm -rf dist

tsconfig-build.json

@@ -0,0 +1,4 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": ["./test/**/*.ts"]
+}

tsconfig.json

@@ -1,5 +1,5 @@
 {
-  "include": ["src/*.ts"],
+  "include": ["src/*.ts", "test/**/*.ts"],
   "compilerOptions": {
     /* Basic Options */
     "target": "es2016" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */,