Reconfigure TypeScript compiler

.gitignore

@@ -3,4 +3,6 @@ node_modules
 package-lock.json
 
 # TypeScript
-/build
+/build
+**/*.d.ts
+**/*.js

package.json

@@ -4,8 +4,8 @@
   "description": "A few useful functions for signing ethereum data",
   "main": "index.js",
   "scripts": {
-    "build": "tsc -d",
-    "test": "npm run build && ts-node test/index.ts"
+    "build": "tsc --project .",
+    "test": "npm run build && node test/index.js"
   },
   "repository": {
     "type": "git",
@@ -22,7 +22,7 @@
   },
   "homepage": "https://github.com/MetaMask/eth-sig-util#readme",
   "dependencies": {
-    "@types/node": "^13.1.2",
+    "@types/node": "^10",
     "buffer": "^5.2.1",
     "elliptic": "^6.4.0",
     "ethereumjs-abi": "0.6.5",
@@ -32,7 +32,6 @@
   },
   "devDependencies": {
     "tape": "^4.9.1",
-    "ts-node": "^8.5.4",
-    "typescript": "3.4.3"
+    "typescript": "3.7.4"
   }
 }

test/index.ts

@@ -509,7 +509,7 @@ test('signedTypeData with V3 string', (t) => {
             { name: 'contents', type: 'string' }
         ],
     },
-    primaryType: 'Mail' as 'Mail',
+    primaryType: 'Mail' as const,
     domain: {
         name: 'Ether Mail',
         version: '1',
@@ -581,7 +581,7 @@ test('signedTypeData_v4', (t) => {
         chainId: 1,
         verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
     },
-    primaryType: 'Mail' as 'Mail',
+    primaryType: 'Mail' as const,
     message: {
         from: {
             name: 'Cow',

tsconfig.json

@@ -1,9 +1,10 @@
 {
   "compilerOptions": {
-    "outDir": "./build",
+    "declaration": true,
     "target": "es5"
   },
   "include": [
+    "./test/**/*",
     "./index.ts",
     "./utils/**/*"
   ]