add simpleHash function & tests, add coverage

.run/ts-mocha.run.xml

@@ -0,0 +1,14 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="ts-mocha" type="mocha-javascript-test-runner">
+    <node-interpreter>project</node-interpreter>
+    <node-options />
+    <mocha-package>$PROJECT_DIR$/node_modules/ts-mocha</mocha-package>
+    <working-directory>$PROJECT_DIR$</working-directory>
+    <pass-parent-env>true</pass-parent-env>
+    <ui>bdd</ui>
+    <extra-mocha-options />
+    <test-kind>PATTERN</test-kind>
+    <test-pattern>$PROJECT_DIR$/test/*.spec.ts</test-pattern>
+    <method v="2" />
+  </configuration>
+</component>

package.json

@@ -5,6 +5,10 @@
   "repository": "https://github.com/tornadocash/fixed-merkle-tree.git",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
+  "engines": {
+    "node": "14.17",
+    "npm": "6"
+  },
   "scripts": {
     "test": "ts-mocha 'test/*.spec.ts'",
     "build": "tsc",
@@ -22,7 +26,6 @@
   "files": [
     "src/*"
   ],
-  "dependencies": {},
   "devDependencies": {
     "@types/expect": "^24.3.0",
     "@types/mocha": "^9.1.0",
@@ -31,6 +34,7 @@
     "chai": "^4.2.0",
     "eslint": "^8.9.0",
     "eslint-config-prettier": "^8.3.0",
+    "nyc": "^15.1.0",
     "mocha": "^9.2.1",
     "ts-mocha": "^9.0.2",
     "typescript": "^4.5.5"

test/simpleHash.spec.ts

@@ -0,0 +1,18 @@
+import simpleHash from '../src/simpleHash'
+import { it } from 'mocha'
+import { should } from 'chai'
+
+describe('SimpleHash', () => {
+  it('should return correct hash string with default params', () => {
+    const hash = simpleHash([1, 2, 3])
+    return should().equal(hash, '3530513397947785053296897142557895557120')
+  })
+  it('should return correct hash string with length param', () => {
+    const hash = simpleHash([1, 2, 3], null, 77)
+    return should().equal(hash, '1259729275322113643079999203492506359813191573070980317691663537897682854338069790720')
+  })
+  it('should return correct hash string with seed param', () => {
+    const hash = simpleHash(['1', '2', '3'], 123)
+    return should().equal(hash, '1371592418687375416654554138100746944512')
+  })
+})