feat: TS v4, tslint -> eslint, add cspell support (#240)

Update all dependencies, migrate from tslint (deprecated) to typescript-eslint, and add support for
cspell.

BREAKING CHANGE: migrated from tslint (deprecated) to eslint.

src/lib/hash.ts

@@ -1,5 +1,6 @@
 import { createHash } from 'crypto';
-import shaJs from 'sha.js';
+
+import { binToHex, instantiateSha256, utf8ToBin } from '@bitauth/libauth';
 
 /**
  * Calculate the sha256 digest of a string.
@@ -7,32 +8,34 @@ import shaJs from 'sha.js';
  * ### Example (es imports)
  * ```js
  * import { sha256 } from 'typescript-starter'
- * sha256('test')
- * // => '9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08'
+ *
+ * (async () => {
+ *   console.log(await sha256('test'));
+ *   // => '9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08'
+ * });
  * ```
  *
+ * @param message - the string to hash
  * @returns sha256 message digest
  */
-export function sha256(message: string): string {
-  return shaJs('sha256')
-    .update(message)
-    .digest('hex');
-}
+export const sha256 = async (message: string) => {
+  const sha256 = await instantiateSha256();
+  return binToHex(sha256.hash(utf8ToBin(message)));
+};
 
 /**
- * A faster implementation of [[sha256]] which requires the native Node.js module. Browser consumers should use [[sha256]], instead.
+ * A synchronous implementation of `sha256` which uses the native Node.js
+ * module. (Browser consumers should use the `sha256` method.)
  *
  * ### Example (es imports)
  * ```js
  * import { sha256Native as sha256 } from 'typescript-starter'
- * sha256('test')
+ * console.log(sha256('test'));
  * // => '9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08'
  * ```
- *
+ * @param message - the string to hash
  * @returns sha256 message digest
  */
-export function sha256Native(message: string): string {
-  return createHash('sha256')
-    .update(message)
-    .digest('hex');
-}
+export const sha256Native = (message: string) => {
+  return createHash('sha256').update(message).digest('hex');
+};