Perform partial build if BUILD_REFNAME is HEAD

Closes gh-31

lib/partial-build-extension.js

@@ -39,7 +39,7 @@ module.exports.register = function ({ config = {} }) {
     }
     if (isBranch && version.endsWith('-SNAPSHOT')) version = version.slice(0, -9)
     const versionsInManifest = Object.values(siteManifestData.components)[0].versions
-    if (!(version in versionsInManifest && isBranch === !!versionsInManifest[version].prerelease)) {
+    if (!isAuthorMode && !(version in versionsInManifest && isBranch === !!versionsInManifest[version].prerelease)) {
       const category = require('path').basename(module.id, '.js')
       await fsp.writeFile(ospath.join(playbook.dir, '.full-build'), '')
       console.log(`${category}: version ${version} not previously built; reverting to full build`)

test/partial-build-extension-test.js

@@ -181,6 +181,28 @@ describe('partial-build-extension', () => {
       })
     })
 
+    it('should rewrite content sources when SNAPSHOT version not found if refname is HEAD', async () => {
+      const playBookDir = WORK_DIR
+      await fsp.mkdir(ospath.join(WORK_DIR, '.git'), { recursive: true })
+      await runScenario({
+        refname: 'HEAD',
+        version: '7.0.0-SNAPSHOT',
+        expectedRefs: { branches: ['HEAD'], tags: [], url: '.' },
+        playbookDir: playBookDir,
+      })
+    })
+
+    it('should rewrite content sources when release version not found if refname is HEAD', async () => {
+      const playBookDir = WORK_DIR
+      await fsp.mkdir(ospath.join(WORK_DIR, '.git'), { recursive: true })
+      await runScenario({
+        refname: 'HEAD',
+        version: '7.0.0',
+        expectedRefs: { branches: ['HEAD'], tags: [], url: '.' },
+        playbookDir: playBookDir,
+      })
+    })
+
     it('should error if refname is HEAD and version undefined', async () => {
       expect(await trapAsyncError(() => runScenario({ refname: 'HEAD' }))).to.throw(
         'When using author mode version is required. Specify config.version or env BUILD_VERSION'