fix(bump): harden prerelease and releaseAs behaviour

lib/lifecycles/bump.js

@@ -20,16 +20,46 @@ async function Bump (args, version) {
   configsToUpdate = {}
 
   if (args.skip.bump) return version
+
+  if (args.releaseAs && !(['major', 'minor', 'patch'].includes(args.releaseAs.toLowerCase()) || semver.valid(args.releaseAs))) {
+    throw new Error("releaseAs must be one of 'major', 'minor' or 'patch', or a valid semvar version.")
+  }
+
   let newVersion = version
   await runLifecycleScript(args, 'prerelease')
   const stdout = await runLifecycleScript(args, 'prebump')
-  if (stdout && stdout.trim().length) args.releaseAs = stdout.trim()
-  const release = await bumpVersion(args.releaseAs, version, args)
+  if (stdout?.trim().length) {
+    const prebumpString = stdout.trim()
+    if (semver.valid(prebumpString)) args.releaseAs = prebumpString
+  }
   if (!args.firstRelease) {
-    const releaseType = getReleaseType(args.prerelease, release.releaseType, version)
-    const releaseTypeAsVersion = releaseType === 'pre' + release.releaseType ? semver.valid(release.releaseType + '-' + args.prerelease + '.0') : semver.valid(releaseType)
+    if (semver.valid(args.releaseAs)) {
+      const releaseAs = new semver.SemVer(args.releaseAs)
+      if (isString(args.prerelease) && releaseAs.prerelease.length && releaseAs.prerelease.slice(0, -1).join('.') !== args.prerelease) {
+        // If both releaseAs and the prerelease identifier are supplied, they must match. The behavior
+        // for a mismatch is undefined, so error out instead.
+        throw new Error('releaseAs and prerelease have conflicting prerelease identifiers')
+      } else if (isString(args.prerelease) && releaseAs.prerelease.length) {
+        newVersion = releaseAs.version
+      } else if (isString(args.prerelease)) {
+        newVersion = `${releaseAs.major}.${releaseAs.minor}.${releaseAs.patch}-${args.prerelease}.0`
+      } else {
+        newVersion = releaseAs.version
+      }
+
+      // Check if the previous version is the same version and prerelease, and increment if so
+      if (isString(args.prerelease) && ['prerelease', null].includes(semver.diff(version, newVersion)) && semver.lte(newVersion, version)) {
+        newVersion = semver.inc(version, 'prerelease', args.prerelease)
+      }
 
-    newVersion = releaseTypeAsVersion || semver.inc(version, releaseType, args.prerelease)
+      // Append any build info from releaseAs
+      newVersion = semvarToVersionStr(newVersion, releaseAs.build)
+    } else {
+      const release = await bumpVersion(args.releaseAs, version, args)
+      const releaseType = getReleaseType(args.prerelease, release.releaseType, version)
+
+      newVersion = semver.inc(version, releaseType, args.prerelease)
+    }
     updateConfigs(args, newVersion)
   } else {
     checkpoint(args, 'skip version bump on first release', [], chalk.red(figures.cross))
@@ -42,6 +72,16 @@ Bump.getUpdatedConfigs = function () {
   return configsToUpdate
 }
 
+/**
+ * Convert a semver object to a full version string including build metadata
+ * @param {string} semverVersion The semvar version string
+ * @param {string[]} semverBuild An array of the build metadata elements, to be joined with '.'
+ * @returns {string}
+ */
+function semvarToVersionStr(semverVersion, semverBuild) {
+  return [semverVersion, semverBuild.join('.')].filter(Boolean).join('+')
+}
+
 function getReleaseType (prerelease, expectedReleaseType, currentVersion) {
   if (isString(prerelease)) {
     if (isInPrerelease(currentVersion)) {

package.json

@@ -56,6 +56,7 @@
   },
   "devDependencies": {
     "chai": "^4.2.0",
+    "chai-as-promised": "^7.1.1",
     "eslint": "^8.16.0",
     "eslint-config-standard": "^17.0.0",
     "eslint-plugin-import": "^2.26.0",

test/config-files.spec.js

@@ -8,7 +8,9 @@ const { Readable } = require('stream')
 const mockery = require('mockery')
 const stdMocks = require('std-mocks')
 
-require('chai').should()
+const chai = require('chai')
+const expect = chai.expect
+chai.use(require('chai-as-promised'))
 
 function exec () {
   const cli = require('../command')
@@ -168,12 +170,7 @@ describe('config files', () => {
   it('throws an error when a non-object is returned from .versionrc.js', async function () {
     mock({ bump: 'minor' })
     fs.writeFileSync('.versionrc.js', 'module.exports = 3', 'utf-8')
-    try {
-      await exec()
-      /* istanbul ignore next */
-      throw new Error('Unexpected success')
-    } catch (error) {
-      error.message.should.match(/Invalid configuration/)
-    }
+
+    expect(exec).to.throw(/Invalid configuration/)
   })
 })