Fixed parsing issue, added more tests

package.json

@@ -1,6 +1,6 @@
 {
   "name": "kd20",
-  "version": "0.3.6",
+  "version": "0.3.7",
   "description": "A simple dice roller that can handle complex die sequences",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",

src/index.ts

@@ -25,16 +25,23 @@ export const parse = (s: string): ParsedBlock[] => {
     cell = cell.toLowerCase()
     cell = cell.replaceAll('(plus)', '+').replaceAll('(minus)', '-')
     if (cell.includes('d')) {
-      const tmp = cell.split('d')
-      if(isNaN(+tmp[0]) || isNaN(+tmp[1])) throw new ParsingError(cell)
-      const isNegative = tmp[0][0] === '-'
+      if(cell[0] === 'd') cell = '1' + cell
+      const splitString = cell.split('d')
+      if(
+        isNaN(+splitString[0]) ||
+        isNaN(+splitString[1]) ||
+        splitString.length !== 2 ||
+        splitString[0] === '' ||
+        splitString[1] === ''
+      ) throw new ParsingError(cell)
+      const isNegative = splitString[0][0] === '-'
       if (isNegative) {
-        tmp[0] = tmp[0].substring(1)
+        splitString[0] = splitString[0].substring(1)
       }
-      for (let i = 0; i < parseInt(tmp[0]); i++) {
+      for (let i = 0; i < parseInt(splitString[0]); i++) {
         res.push({
           type: 'die',
-          maxValue: parseInt(tmp[1]),
+          maxValue: parseInt(splitString[1]),
           negative: isNegative
         })
       }

tests/parse.test.ts

@@ -18,6 +18,11 @@ test('Parse a negative value or die correctly', () => {
   expect(result2).toEqual([{ type: 'fixed', maxValue: -3 }])
 })
 
+test('Parse d20 (implicit 1d20)', () => {
+  const result = parse('d20')
+  expect(result).toEqual([{ type: 'die', maxValue: 20, negative: false }])
+})
+
 test('Parse a complex string', () => {
   const result = parse('3d6 + 1d4 - 5 - 2d4 + 1')
   expect(result).toEqual([
@@ -37,5 +42,11 @@ test('Throw an exception for an invalid string', () => {
   expect(() => parse('+f')).toThrow(ParsingError)
   expect(() => parse('3dz')).toThrow(ParsingError)
   expect(() => parse('4d4sss')).toThrow(ParsingError)
+  expect(() => parse('dd20')).toThrow(ParsingError)
+  expect(() => parse('2dd20')).toThrow(ParsingError)
+  expect(() => parse('2d')).toThrow(ParsingError)
+  expect(() => parse('2dd')).toThrow(ParsingError)
+  expect(() => parse('2d   2d')).toThrow(ParsingError)
+  expect(() => parse('d1d4')).toThrow(ParsingError)
 })