fix: throw on missing info during release prep (#519)

lib/prepare_release.js

@@ -31,6 +31,12 @@ class ReleasePreparation {
     this.date = '';
     this.config = getMergedConfig(this.dir);
 
+    // Ensure the preparer has set an upstream and username.
+    if (this.warnForMissing()) {
+      cli.error('Failed to begin the release preparation process.');
+      return;
+    }
+
     // Allow passing optional new version.
     if (argv.newVersion) {
       const newVersion = semver.clean(argv.newVersion);
@@ -224,6 +230,33 @@ class ReleasePreparation {
     return this.config.username;
   }
 
+  warnForMissing() {
+    const { cli, upstream, username } = this;
+
+    const missing = !username || !upstream;
+    if (!upstream) {
+      cli.warn('You have not told git-node the remote you want to sync with.');
+      cli.separator();
+      cli.info(
+        'For example, if your remote pointing to nodejs/node is' +
+        ' `remote-upstream`, you can run:\n\n' +
+        '  $ ncu-config set upstream remote-upstream');
+      cli.separator();
+      cli.setExitCode(1);
+    }
+    if (!username) {
+      cli.warn('You have not told git-node your username.');
+      cli.separator();
+      cli.info(
+        'To fix this, you can run: ' +
+        '  $ ncu-config set username <your_username>');
+      cli.separator();
+      cli.setExitCode(1);
+    }
+
+    return missing;
+  }
+
   calculateNewVersion() {
     let newVersion;