---
title: "Validate shared declarations once without losing file boundaries"
description: "Validate shared declarations in one pass, and keep each file's own syntax check."
url: https://starsling.dev/ci-playbooks/techniques/batch-semantic-validation
canonicalUrl: https://starsling.dev/ci-playbooks/techniques/batch-semantic-validation
---

# Validate shared declarations once without losing file boundaries

Validate shared declarations in one pass, and keep each file's own syntax check.

## How to choose an approach

This technique currently has one documented company example. Validate its prerequisites, tradeoffs and original CI environment against your repository before adapting it.

- **[OpenAI](https://starsling.dev/ci-playbooks/openai#batch-semantic-validation)**: Use it when A declaration validator analyzes the same reopened namespaces again for every file. Check before adopting: Concatenation can make invalid files look valid together or leak file-scoped directives. Keep the per-file fallback with exact diagnostics.

## Apply this technique

````text
Evaluate and apply this CI technique to my repository: Validate shared declarations once without losing file boundaries.

Validate shared declarations in one pass, and keep each file's own syntax check.

Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/batch-semantic-validation.md

Inspect this repository’s CI workflows, build and test commands, dependencies, and recent run timings. Identify where this technique applies and explain the expected benefit using this repository’s evidence.
Measure a baseline from recent comparable runs: elapsed time, queue time, runner minutes and failures where available. If data is unavailable, say what cannot be measured.
Compare relevant company approaches, checking prerequisites, platform differences and tradeoffs. Rank applicable options by evidence, fit and measurable opportunity; do not present company results as predictions for this repo.
Recommend the smallest safe change, show what checks and fallback paths remain, and ASK ME WHICH CHANGE TO APPROVE BEFORE EDITING ANY FILES.
Only after approval, work on a new feature branch, make one reversible change, and open a reviewable pull request. Never merge or push to a default or protected branch.
Keep required checks, test coverage, deployment and release behavior intact. Validate the change and compare equivalent runs where possible; report limitations and what should be monitored after merge.
````

## How OpenAI used this technique

Read what OpenAI changed and follow the original sources.

### OpenAI: Validate shared declarations once without losing file boundaries

The Ruby SDK parses each of its 1,209 RBS files on its own, then runs one consolidated Steep pass for semantics. If any file has NUL bytes or file-scoped directives, the whole job takes the per-file path, and any error in the fast path reruns the original files for exact diagnostics.

Evidence: Source PR/commit evidence

Complete local validator: per-file Steep run 52.38s to 6.22s consolidated ([Source](https://github.com/openai/openai-ruby/pull/333))

Use it when: A declaration validator analyzes the same reopened namespaces again for every file.

Before applying it: Concatenation can make invalid files look valid together or leak file-scoped directives. Keep the per-file fallback with exact diagnostics.

[Read more in the OpenAI playbook](https://starsling.dev/ci-playbooks/openai#batch-semantic-validation)

[Primary source](https://github.com/openai/openai-ruby/pull/333)

## CI optimization is continuous work.

Apply this technique yourself, or use StarSling Runners for faster GitHub Actions and optional agent-driven optimization PRs, which teams on eligible paid plans can turn on.

[Get self-improving CI](https://starsling.dev/products/runners)

## Company Playbooks

### [Anthropic](https://starsling.dev/ci-playbooks/anthropic)

Run only affected tests

### [DoorDash](https://starsling.dev/ci-playbooks/doordash)

Run build and test in parallel, sharded across CI agents

### [Linear](https://starsling.dev/ci-playbooks/linear)

Benchmark the same job on faster hardware

### [Mastra](https://starsling.dev/ci-playbooks/mastra)

StarSling runners for the slowest test workflow

### [OpenAI](https://starsling.dev/ci-playbooks/openai)

Rank CI fixes by the minutes they save

### [Ramp](https://starsling.dev/ci-playbooks/ramp)

Move a CPU-bound test suite to a faster CPU

### [Shopify](https://starsling.dev/ci-playbooks/shopify)

Let an agent iterate against one CI metric

### [Spotify](https://starsling.dev/ci-playbooks/spotify)

Build arm64 on native arm64 runners

### [Stripe](https://starsling.dev/ci-playbooks/stripe)

Run only the tests a change can reach

### [Uber](https://starsling.dev/ci-playbooks/uber)

Build the merge-queue speculations most likely to be needed