fix: #247 throw an error in case of a missing object value

src/parse.ts

@@ -63,6 +63,10 @@ export function parse(
         eatColon()
         const value = parseValue()
 
+        if (value === undefined) {
+          throwObjectValueExpected()
+        }
+
         // TODO: test deep equal instead of strict equal
         if (Object.prototype.hasOwnProperty.call(object, key) && !isDeepEqual(value, object[key])) {
           // Note that we could also test `if(key in object) {...}`
@@ -291,6 +295,10 @@ export function parse(
     throw new SyntaxError(`Invalid escape character '${chars}' ${pos()}`)
   }
 
+  function throwObjectValueExpected() {
+    throw new SyntaxError(`Object value expected after ':' ${pos()}`)
+  }
+
   function throwInvalidUnicodeCharacter(start: number) {
     let end = start + 2
     while (/\w/.test(text[end])) {

test/parse.test.ts

@@ -344,6 +344,10 @@ describe('throw meaningful exceptions', () => {
       input: '{"a",',
       expectedError: "Colon ':' expected after property name but got ',' at position 4"
     },
+    {
+      input: '{"a":}',
+      expectedError: "Object value expected after ':' at position 5"
+    },
     { input: '{a:2}', expectedError: "Quoted object key expected but got 'a' at position 1" },
     { input: '{"a":2,}', expectedError: "Quoted object key expected but got '}' at position 7" },
     {
@@ -361,6 +365,7 @@ describe('throw meaningful exceptions', () => {
         "Array item or end of array ']' expected but reached end of input at position 1"
     },
     { input: '[2,]', expectedError: "Array item expected but got ']' at position 3" },
+    { input: '[2,,3]', expectedError: "Array item expected but got ',' at position 3" },
     { input: '[2 3]', expectedError: "Comma ',' expected after value but got '3' at position 3" },
     { input: '2.3.4', expectedError: "Expected end of input but got '.' at position 3" },
     {