Running one named test file, matching a partial filename, passing a test-file option, and testing files in the Iress Design System components package.

They remove uncertainty about how to target a single test instead of running every test. They also point out that test files must be inside the package’s src directory.

How iress/design-system configures GitHub Copilot

Q: What is design-system testing-single-files.instructions.md?

Instructions for running one test file in a Yarn workspace, where a workspace is one package inside a larger monorepo. They show direct commands, filename matching, required test-file locations, and extra command options.

Reuse

Borrowing it

Nothing to install: this file belongs to iress/design-system. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/iress/design-system/main/.github/instructions/testing-single-files.instructions.md

Clone the repo

git clone --depth 1 https://github.com/iress/design-system

Made for: GitHub Copilot.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/iress/design-system/testing-single-files/github.svg)](https://agentmods.dev/instructions/iress/design-system/testing-single-files)

Your own site

<a href="https://agentmods.dev/instructions/iress/design-system/testing-single-files"><img src="https://agentmods.dev/badge/instructions/iress/design-system/testing-single-files/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/iress/design-system/testing-single-files"><img src="https://agentmods.dev/badge/instructions/iress/design-system/testing-single-files.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 533 This file is loaded in full into every session.

When invoked 533 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00533	$0.00533
Opus 5.5	$0.00213	$0.00213
Sonnet 5.5	$0.00107	$0.00107
Haiku 4.5	$0.00053	$0.00053

Measured 2mo ago against content hash cf34aea4d357, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

design-system testing-single-files.instructions.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.github/instructions/testing-single-files.instructions.md · 62 lines

How it starts

The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Running Single Tests with Yarn Workspaces

🎯 Direct Yarn Workspace Commands (Recommended):

# Run a specific test file using --testFile flag
yarn workspace @iress-oss/ids-components run test:coverage -- --testFile MyComponent.test.tsx

# Run any project with a specific file
yarn workspace <package-name> run test:coverage -- --testFile <filename>

🔧 Additional Test Command Options:

# Method 1: Using --testFile flag
yarn workspace @iress-oss/ids-components run test:coverage -- --testFile MyComponent.test.tsx

# Method 2: Using positional argument (regex pattern)
yarn workspace @iress-oss/ids-components run test:coverage -- MyComponent.test.tsx

# Method 3: Using partial filename matching
yarn workspace @iress-oss/ids-components run test:coverage -- MyComponent

📂 File Structure Requirements:

Test files must be in the project's src/ directory:

✅ packages/components/src/MyComponent.test.tsx
❌ packages/components/MyComponent.test.tsx (wrong location)

🚀 Real Examples:

# Test our example files
yarn workspace @iress-oss/ids-components run test:coverage -- --testFile test-file-2.test.ts

# Or using the shortcuts
yarn test:components:file test-file-2.test.ts

💡 Pro Tips:

Regex matching: yarn workspace @iress-oss/ids-components run test -- Button will match Button.test.tsx, ButtonGroup.test.tsx, etc.
Watch mode: Add --watch to any command for continuous testing
UI mode: Add --ui to any command for the Vitest UI
Coverage: Tests run with coverage by default in this project

🔥 Most Common Usage:

# Quick test of a specific component
yarn workspace @iress-oss/ids-components run test:coverage -- --testFile Button.test.tsx

# Watch mode while developing
yarn workspace @iress-oss/ids-components run test:coverage -- --testFile Button.test.tsx --watch

# UI mode for debugging
yarn workspace @iress-oss/ids-components run test:coverage -- --testFile Button.test.tsx --ui

Read the full file on GitHub · 62 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 62 lines · 533 tokens per session scan A cf34aea4d357

Subscribe to this mod's changes

design-system testing-single-files.instructions.md is an instructions file published in the GitHub repository iress/design-system (1 stars, last pushed 2d ago), licensed Apache-2.0. It adds 533 tokens to every session, about $0.0021 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Testing

design-system testing-single-files.instructions.md next to 6 instructions from other repositories
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design-system testing-single-files.instructions.mdiress/design-system	Instructions file	1	2d ago	Apache-2.0	A	533	GitHub Copilot
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vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

design-system: Instructions file for GitHub Copilot