Handle offline scenarios more gracefully (#305)

If a Yarn install command fails due to connectivity issues, we should
provide actionable advice on next steps to the user.

Author: 72636c

.changeset/mean-rice-film.md

@@ -0,0 +1,5 @@
+---
+'skuba': patch
+---
+
+**configure, init:** Improve error messaging in offline scenarios

src/cli/configure/index.ts

@@ -106,12 +106,29 @@ export const configure = async () => {
       streamStdio: 'yarn',
     });
 
-    log.plain('Installing dependencies...');
-    await exec('yarn', 'install', '--silent');
+    log.newline();
+    try {
+      await exec('yarn', 'install');
+    } catch {
+      log.newline();
+      log.warn(log.bold('✗ Failed to install dependencies. Resume with:'));
+
+      log.newline();
+      log.plain(log.bold('yarn install'));
+      log.plain(log.bold('yarn format'));
+
+      log.newline();
+      process.exit(1);
+    }
   }
 
   if (fixConfiguration || fixDependencies) {
     log.newline();
-    log.ok(`Try running ${log.bold('yarn format')}.`);
+    log.ok(log.bold('✔ All done! Try running:'));
+
+    log.newline();
+    log.plain(log.bold('yarn format'));
   }
+
+  log.newline();
 };

src/cli/init/index.ts

@@ -79,22 +79,37 @@ export const init = async () => {
   log.newline();
   await initialiseRepo(exec, templateData);
 
-  log.plain('Installing dependencies...');
-  await exec(
-    'yarn',
-    'add',
-    '--dev',
-    '--exact',
-    '--silent',
-    `skuba@${skubaVersionInfo.local}`,
-  );
+  const skubaSlug = `skuba@${skubaVersionInfo.local}`;
+
+  let depsInstalled = false;
+  try {
+    await exec('yarn', 'add', '--dev', skubaSlug);
+    depsInstalled = true;
+  } catch {}
 
   await commitChanges(exec, `Clone ${templateName}`);
 
+  if (!depsInstalled) {
+    log.newline();
+    log.warn(log.bold('✗ Failed to install dependencies. Resume with:'));
+
+    log.newline();
+    log.plain(log.bold('cd', destinationDir));
+    log.plain(log.bold('yarn add --dev', skubaSlug));
+    log.plain(log.bold('git add --all'));
+    log.plain(log.bold('git commit --message', `'Pin ${skubaSlug}'`));
+    log.plain(log.bold('git push --set-upstream origin master'));
+
+    log.newline();
+    process.exit(1);
+  }
+
+  log.newline();
+  log.ok(log.bold('✔ All done! Try running:'));
+
   log.newline();
-  log.ok('✔ All done! Try running:');
+  log.plain(log.bold('cd', destinationDir));
+  log.plain(log.bold('git push --set-upstream origin master'));
 
   log.newline();
-  log.ok(log.bold('cd', destinationDir));
-  log.ok(log.bold('git push --set-upstream origin master'));
 };

src/utils/exec.ts

@@ -10,6 +10,33 @@ import npmWhich from 'npm-which';
 import { ConcurrentlyErrors, isErrorWithCode } from './error';
 import { log } from './logging';
 
+class YarnSpamFilter extends stream.Transform {
+  silenced = false;
+
+  _transform(
+    chunk: any,
+    _encoding: BufferEncoding,
+    callback: stream.TransformCallback,
+  ) {
+    const str = Buffer.from(chunk).toString();
+
+    // Yarn spews the entire installed dependency tree after this message
+    if (str.startsWith('info Direct dependencies')) {
+      this.silenced = true;
+    }
+
+    if (
+      !this.silenced &&
+      // This isn't very useful given the command generates a lockfile
+      !str.startsWith('info No lockfile found')
+    ) {
+      this.push(chunk);
+    }
+
+    callback();
+  }
+}
+
 class YarnWarningFilter extends stream.Transform {
   _transform(
     chunk: any,
@@ -54,10 +81,11 @@ const runCommand = (command: string, args: string[], opts?: ExecOptions) => {
 
   switch (opts?.streamStdio) {
     case 'yarn':
-      const filter = new YarnWarningFilter();
+      const stderrFilter = new YarnWarningFilter();
+      const stdoutFilter = new YarnSpamFilter();
 
-      subprocess.stderr?.pipe(filter).pipe(process.stderr);
-      subprocess.stdout?.pipe(process.stdout);
+      subprocess.stderr?.pipe(stderrFilter).pipe(process.stderr);
+      subprocess.stdout?.pipe(stdoutFilter).pipe(process.stdout);
 
       break;