fix: preserve build in raw after inc

Fixes: #562

Author: lukekarrys

Diff for: classes/semver.js

@@ -291,8 +291,10 @@ class SemVer {
       default:
         throw new Error(`invalid increment argument: ${release}`)
     }
-    this.format()
-    this.raw = this.version
+    this.raw = this.format()
+    if (this.build.length) {
+      this.raw += `+${this.build.join('.')}`
+    }
     return this
   }
 }

Diff for: test/classes/semver.js

@@ -81,7 +81,7 @@ test('invalid version numbers', (t) => {
 })
 
 test('incrementing', t => {
-  t.plan(increments.length)
+  t.plan(increments.length + 1)
   increments.forEach(([
     version,
     inc,
@@ -97,6 +97,18 @@ test('incrementing', t => {
       t.equal(new SemVer(version, options).inc(inc, id, base).version, expect)
     }
   }))
+  t.test('preserve build in raw', t => {
+    // https://github.com/npm/node-semver/issues/562
+    t.plan(2)
+    t.equal(
+      new SemVer('1.0.0-rc.1+build.4').inc('prerelease', 'rc').raw,
+      '1.0.0-rc.2+build.4'
+    )
+    t.equal(
+      new SemVer('1.0.0-rc.1').inc('prerelease', 'rc').raw,
+      '1.0.0-rc.2'
+    )
+  })
 })
 
 test('compare main vs pre', (t) => {