build: Add separate tsconfig for test script

The definitions for `require` and `module` clash with `@types/node`,
which is needed to run the test script (`run-tests.ts`).
To keep the setup working, separate `tsconfig.json` into two files:

- `tsconfig.json` is used to compile `src/` and `test-d/`.
- `tsconfig.test.json` is used to compiel `run-tests.ts`.

Also make ts-node use `tsconfig.test.json` for this.
(Hopefully, all this mess can be removed once #21 is merged.)

package.json

@@ -21,7 +21,7 @@
   "scripts": {
     "lint": "gts lint",
     "fix": "gts fix",
-    "test": "ts-node run-tests.ts",
+    "test": "ts-node --project tsconfig.test.json run-tests.ts",
     "posttest": "npm run lint"
   },
   "repository": {

tsconfig.json

@@ -1,6 +1,8 @@
 {
   "extends": "./node_modules/gts/tsconfig-google.json",
   "compilerOptions": {
-    "resolveJsonModule": true
-  }
+    // We don't want @types/node to interfere with our own types (e.g. require())
+    "types": []
+  },
+  "include": ["src", "test-d"]
 }

tsconfig.test.json

@@ -0,0 +1,7 @@
+{
+  "extends": "gts/tsconfig-google.json",
+  "compilerOptions": {
+    "resolveJsonModule": true
+  },
+  "exclude": ["src", "test-d"]
+}