fix: await function template downloads in functions-create

[jherr]

Two bugs in downloadFromURL (src/commands/functions/functions-create.ts), both on the netlify functions:create --url path.

Template downloads were never awaited. Files were written with res.body?.pipe(dest) — no await, so Promise.all resolved before any write had finished. The cp.exec('npm i', ...) that immediately follows could therefore run against a partially-written function directory. await pipeline(res.body, dest) closes the race.

A failed download was written to disk as the template. There was no res.ok check, so a 404 or 500 from GitHub had its error-page body piped into the function file and the command reported success. That's now an explicit throw, which the surrounding catch turns into the existing Error while retrieving ${downloadUrl} message.

 const res = await fetch(downloadUrl)
+if (!res.ok || !res.body) {
+  throw new Error(`HTTP ${res.status.toString()}: ${res.statusText}`)
+}
 const fileName = path.basename(name)
 const finalName = path.basename(fileName, '.js') === functionName ? `${nameToUse}.js` : fileName
 const dest = fs.createWriteStream(path.join(fnFolder, finalName))
-res.body?.pipe(dest)
+await pipeline(res.body, dest)

The node-fetch import is unchanged — node-fetch v3's res.body is a Node Readable typed NodeJS.ReadableStream | null, which satisfies PipelineSource, so this is purely the bug fix.

Verification

• npm run typecheck, npm run lint, npm run format:check — clean
• npm run test:unit — 499/500, matching the baseline on unmodified main exactly (the generate-autocompletion snapshot failure is pre-existing; I reproduced it on main at 97fd77d3c)

No package-lock.json change.

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Split out of #8453, which bundled this with unrelated work.

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Run ID: 2da71e25-cb14-445e-a465-f5740913ed36

📥 Commits

Reviewing files that changed from the base of the PR and between 97fd77d and 65c4504.

📒 Files selected for processing (1)

• src/commands/functions/functions-create.ts

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📝 Summary

Summary by CodeRabbit

• Bug Fixes
  • Improved reliability when downloading GitHub templates by detecting failed or empty responses.
  • Ensured template files finish writing before the download process completes.

Walkthrough

The template download flow now validates HTTP responses and requires a response body. It throws an HTTP error for failed or empty responses. It awaits pipeline to complete each file write.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to 65c45

URL-based function template downloads now reject invalid responses and wait for file writes to finish, preventing incomplete or error-content templates. The change is ready to merge.

Suggested reviewers: amun-sihra

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description check	✅ Passed	The description clearly explains the two download bugs, the implementation changes, and the verification results. It is directly related to the changeset.
Title check	✅ Passed	The title clearly and concisely identifies the main change: awaiting function template downloads in functions-create.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 1…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 1 files.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/functions-create-await-downloads

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📊 Benchmark results

Comparing with 97fd77d

• Dependency count: 1,088 (no change)
• Package size: 441 MB ⬆️ 0.00% increase vs. 97fd77d
• Number of ts-expect-error directives: 346 (no change)

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commit: 65c4504