changes to support ghes alpha release (#199)

src/url-helper.ts

@@ -0,0 +1,28 @@
+import * as assert from 'assert'
+import {IGitSourceSettings} from './git-source-settings'
+import {URL} from 'url'
+
+export function getApiUrl(): string {
+  return process.env['GITHUB_API_URL'] || 'https://api.github.com'
+}
+
+export function getFetchUrl(settings: IGitSourceSettings): string {
+  assert.ok(
+    settings.repositoryOwner,
+    'settings.repositoryOwner must be defined'
+  )
+  assert.ok(settings.repositoryName, 'settings.repositoryName must be defined')
+  const serviceUrl = getServerUrl()
+  const encodedOwner = encodeURIComponent(settings.repositoryOwner)
+  const encodedName = encodeURIComponent(settings.repositoryName)
+  if (settings.sshKey) {
+    return `git@${serviceUrl.hostname}:${encodedOwner}/${encodedName}.git`
+  }
+
+  // "origin" is SCHEME://HOSTNAME[:PORT]
+  return `${serviceUrl.origin}/${encodedOwner}/${encodedName}`
+}
+
+export function getServerUrl(): URL {
+  return new URL(process.env['GITHUB_URL'] || 'https://github.com')
+}