Add support for version numbers with a v prefix

Author: socsieng

src/util/version.spec.ts

@@ -4,6 +4,7 @@ describe('Parse', () => {
   test.each([
     ['1', '1'],
     ['1.0', '1.0'],
+    ['v1.0', '1.0'],
     ['1.0-beta', '1.0-beta'],
     ['1.10.3', '1.10.3'],
     ['1.10.3.4', '1.10.3.4'],
@@ -23,6 +24,7 @@ describe('Parse', () => {
     ['0x1'],
     ['.1'],
     ['0.1..'],
+    ['b0.1'],
     ['1.10.3.5.alpha'],
   ])('should fail to parse version %s', (versionNumber) => {
     expect(() => {
@@ -36,6 +38,8 @@ describe('Compare', () => {
   test.each([
     ['1', '1', 0],
     ['1.0', '1', 0],
+    ['v1.0', '1', 0],
+    ['v1.0', '1.0', 0],
     ['1.01-beta', '1.1-beta', 0],
     ['1.1', '1.1-beta', -1],
     ['1.10', '1.10.3', -1],

src/util/version.ts

@@ -1,4 +1,4 @@
-const VersionExpression = /^(\d)+(\.(\d+))?(\.(\d+))?(\.(\d+))?(-([\w][\w.-]*))?$/;
+const VersionExpression = /^v?(\d)+(\.(\d+))?(\.(\d+))?(\.(\d+))?(-([\w][\w.-]*))?$/;
 
 export default class Version {
   readonly major: number;