use-internals-di-seam-pattern-for-test-injectable-functions

use-internals-di-seam-pattern-for-test-injectable-functions is a skill for OpenCode from ZaxbyHub/opencode-swarm. It costs 27 tokens per session (478 once invoked), scanned A, original, MIT.

A testing guideline for making functions easier to replace with controlled test versions and avoiding shared mock state between test files.

In plain words
What is it for?
Designing testable functions, isolating Bun test mocks, and checking behavior across combined test runs.
Why use it?
It prevents tests from passing alone but failing when the full test suite runs together.

Skill for OpenCode

Written for OpenCode: installed under .opencode/. Also seen: mentions OpenCode.

Good fit Designing testable functions, isolating Bun test mocks, and checking behavior across combined test runs.

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Install with agentmods
npx agentmods add skills/zaxbyhub/opencode-swarm/use-internals-di-seam-pattern-for-test-injectable-functions
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add ZaxbyHub/opencode-swarm --skill use-internals-di-seam-pattern-for-test-injectable-functions
Clone the repo
git clone --depth 1 https://github.com/ZaxbyHub/opencode-swarm

Made for: OpenCode.

Wrote this? Show the measurements

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Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 478 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00027 $0.00478
Opus 5.5 $0.00011 $0.00191
Sonnet 5.5 $0.00005 $0.00096
Haiku 4.5 $0.00003 $0.00048

Measured 14d ago against content hash b23aa92dc8ea, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

use-internals-di-seam-pattern-for-test-injectable-functions scanned grade A with 1 finding 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 14d 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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

- 8a374ec6-734e-4b34-9119-1b6148db3a1e — In Bun's shared test-runner process, mock.module() leaks across test files. Always use _internals DI seams or spread-real-exports for node:fs/child_process mocks instead of bare m
.opencode/skills/generated/use-internals-di-seam-pattern-for-test-injectable-functions/SKILL.md · 52 lines

What it actually says

use _internals DI seam pattern for test-injectable functions

Trigger

  • (no explicit trigger metadata; cluster derived from category/tags)

Required Procedure

  • use _internals DI seam pattern for test-injectable functions
  • spread real module exports when mocking node built-ins (import * as real from 'node:module'; mock.module('node:module', () => ({ ...real, targetFn: mockFn })))
  • verify mock isolation by running test files in combined mode, not individually

Forbidden Shortcuts

  • rely on mock.module() isolation between test files in bun:test
  • declare a test passing based solely on individual file execution

Delegation Template

When delegating a task affected by this skill, include:

SKILLS: file:.opencode/skills/generated/use-internals-di-seam-pattern-for-test-injectable-functions/SKILL.md

Reviewer Checks

  • Verify each required action above appears in the diff.

Test Engineer Checks

  • Add or update tests covering the trigger condition and the forbidden shortcut.

Source Knowledge IDs

  • 8a374ec6-734e-4b34-9119-1b6148db3a1e — In Bun's shared test-runner process, mock.module() leaks across test files. Always use _internals DI seams or spread-real-exports for node:fs/child_process mocks instead of bare mock.module().
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.

  1. 14d ago Changed · -1 lines b23aa92dc8ea
  2. 1mo ago First seen · 53 lines · 27 tokens per session scan A c5aa8b68fdc8

Subscribe to this mod's changes

use-internals-di-seam-pattern-for-test-injectable-functions is a skill published in the GitHub repository ZaxbyHub/opencode-swarm (513 stars, last pushed today), licensed MIT. It adds 27 tokens to every session and 478 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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