refactor(cli): replace spawnSync("sleep") with native wait utility

[jyaunches]

Summary

Credit: This PR is based on the original work by @ksapru in #2027. Rebased on current main to incorporate recent security hardening (#1915), NGC login prompt (#2043), installer integrity check (#2046), and docs fixes (#2106).

Replaces all spawnSync("sleep", ...) subprocess calls with a native Node.js sleepSeconds() utility backed by Atomics.wait. This eliminates the overhead of spawning a child process for every delay and removes a platform dependency on the sleep binary.

Related Issue

Refs #2001 (Phase 2: replace sleeps with event-driven waits)
Supersedes #2027

Changes

• New: src/lib/wait.ts — sleepMs() and sleepSeconds() primitives using Atomics.wait(SharedArrayBuffer) for CPU-friendly synchronous blocking
• Refactored: Replaced spawnSync("sleep", ...) in src/nemoclaw.ts, src/lib/onboard.ts, src/lib/deploy.ts, src/lib/agent-onboard.ts, and src/lib/nim.ts
• Tests: test/wait.test.ts — timing accuracy, edge cases (zero, negative, NaN, Infinity)

Type of Change

• Code change (feature, bug fix, or refactor)
• Code change with doc updates
• Doc only (prose changes, no code sample modifications)
• Doc only (includes code sample changes)

Verification

• npx prek run --all-files passes
• npm test passes
• Tests added or updated for new or changed behavior
• No secrets, API keys, or credentials committed
• Docs updated for user-facing behavior changes

AI Disclosure

• AI-assisted — tool: Claude (pi agent)

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Signed-off-by: Test User test@example.com

Summary by CodeRabbit

• Refactor

  • Replaced ad-hoc OS-level sleeps with a single internal wait utility to standardize delays used in polling and retry flows across the CLI.

• Tests

  • Added tests verifying the wait utility's timing and edge-case behavior to ensure predictable delays during operations.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between b3ec7c4 and 821bfa9.

📒 Files selected for processing (1)

• src/lib/nim.ts

🚧 Files skipped from review as they are similar to previous changes (1)

• src/lib/nim.ts

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📝 Walkthrough

Walkthrough

Replaces ad-hoc OS-level sleep calls with a shared blocking sleep utility (sleepMs / sleepSeconds implemented with SharedArrayBuffer + Atomics.wait) and updates callers to use sleepSeconds() for delays in health/probe and retry loops.

Changes

Cohort / File(s)	Summary
Wait Module src/lib/wait.ts	Adds sleepMs(ms: number): void and sleepSeconds(seconds: number): void implemented with SharedArrayBuffer + Atomics.wait(), including input validation for non-positive and non-finite values.
Sleep Implementation Migration src/lib/agent-onboard.ts, src/lib/deploy.ts, src/lib/nim.ts, src/lib/onboard.ts, src/nemoclaw.ts	Replaces local/inline spawnSync("sleep", ...) invocations with imported sleepSeconds(); preserves existing loop bounds, retry logic, and timeouts.
Tests test/wait.test.ts	Adds Vitest suite validating timing behavior for sleepMs() and sleepSeconds() (positive durations) and quick-return behavior for non-positive/non-finite inputs.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

🐇 I tap the buffer, still and small,

Atomics hush — I hear no call.
No spawned shells to wake the night,
One quiet wait keeps timing right.
Hops in sync, the code feels light.

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 40.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: replacing spawnSync("sleep") calls with a native wait utility, which is the primary objective of this refactor.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

🧹 Nitpick comments (1)

src/lib/nim.ts (1)

276-277: Remove stale ESLint suppression near the new sleep call.

The suppression targets no-require-imports, but this line no longer uses require.

🧹 Proposed cleanup

-    // eslint-disable-next-line `@typescript-eslint/no-require-imports`
     sleepSeconds(intervalSec);

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/lib/nim.ts` around lines 276 - 277, Remove the stale ESLint suppression
placed directly above the sleepSeconds call: delete the comment "//
eslint-disable-next-line `@typescript-eslint/no-require-imports`" that precedes
sleepSeconds(intervalSec); in the code (referencing the sleepSeconds invocation)
so the file no longer silences a rule that isn’t relevant; if other nearby lines
still require suppressions, replace with the appropriate rule only where needed.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@src/lib/nim.ts`:
- Around line 276-277: Remove the stale ESLint suppression placed directly above
the sleepSeconds call: delete the comment "// eslint-disable-next-line
`@typescript-eslint/no-require-imports`" that precedes sleepSeconds(intervalSec);
in the code (referencing the sleepSeconds invocation) so the file no longer
silences a rule that isn’t relevant; if other nearby lines still require
suppressions, replace with the appropriate rule only where needed.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: a25186c7-8d8b-4293-92f3-8fd79ab6378f

📥 Commits

Reviewing files that changed from the base of the PR and between ed38d45 and 7fda280.

📒 Files selected for processing (7)

• src/lib/agent-onboard.ts
• src/lib/deploy.ts
• src/lib/nim.ts
• src/lib/onboard.ts
• src/lib/wait.ts
• src/nemoclaw.ts
• test/wait.test.ts

[wscurran]

✨
Possibly related open PRs:

• #2027 refactor(cli): replace spawnSync("sleep") with native wait utility
• #2046 fix(security): add SHA-256 integrity verification for k8s installer download
• #1915 fix(security): migrate remaining shell-string callsites to argv arrays

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Possibly related open PRs:

• #2027 refactor(cli): replace spawnSync("sleep") with native wait utility
• #2046 fix(security): add SHA-256 integrity verification for k8s installer download
• #1915 fix(security): migrate remaining shell-string callsites to argv arrays

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Possibly related open issues:

• #2001 perf: investigate and reduce networking latency during onboard and validation