What is dotnet-testing-advanced-testcontainers-database?

Guidance for integration tests that use Testcontainers, a library that starts real services in temporary Docker containers, with databases such as SQL Server, PostgreSQL, or MySQL.

Use it to test EF Core or Dapper code against real database instances, including setup, migrations, isolation, and cleanup.

It helps catch database behavior that an in-memory substitute cannot reproduce, such as transactions, SQL differences, constraints, and concurrency.

dotnet-testing-advanced-testcontainers-database — Skill for Claude Code and Codex by kevintsengtw: Guidance for integration tests that use T

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.

agentmods

npx agentmods add skills/kevintsengtw/dotnet-testing-agent-skills/dotnet-testing-advanced-testcontainers-database

Any agent

npx skills add kevintsengtw/dotnet-testing-agent-skills --skill dotnet-testing-advanced-testcontainers-database

Clone the repo

git clone --depth 1 https://github.com/kevintsengtw/dotnet-testing-agent-skills

Made for: Claude Code, Codex.

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/skills/kevintsengtw/dotnet-testing-agent-skills/dotnet-testing-advanced-testcontainers-database.svg)](https://agentmods.dev/skills/kevintsengtw/dotnet-testing-agent-skills/dotnet-testing-advanced-testcontainers-database)

Your own site

<a href="https://agentmods.dev/skills/kevintsengtw/dotnet-testing-agent-skills/dotnet-testing-advanced-testcontainers-database"><img src="https://agentmods.dev/badge/skills/kevintsengtw/dotnet-testing-agent-skills/dotnet-testing-advanced-testcontainers-database.svg" alt="Measured on agentmods" height="20"></a>

Per session 199 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,553 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

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	$0.00199	$0.02553
Opus 5	$0.00100	$0.01277
Sonnet 5	$0.00040	$0.00511
Haiku 4.5	$0.00020	$0.00255

Measured 6d ago against content hash 77991bf44e70, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

dotnet-testing-advanced-testcontainers-database 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 6d 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.

skills/dotnet-testing-advanced-testcontainers-database/SKILL.md · 181 lines

How it starts

The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Testcontainers 資料庫整合測試指南

EF Core InMemory 的限制

在選擇測試策略前，必須了解 EF Core InMemory 資料庫的重大限制：

1. 交易行為與資料庫鎖定

不支援資料庫交易 (Transactions)：SaveChanges() 後資料立即儲存，無法進行 Rollback
無資料庫鎖定機制：無法模擬並發 (Concurrency) 情境下的行為

2. LINQ 查詢差異

查詢翻譯差異：某些 LINQ 查詢（複雜 GroupBy、JOIN、自訂函數）在 InMemory 中可執行，但轉換成 SQL 時可能失敗
Case Sensitivity：InMemory 預設不區分大小寫，但真實資料庫依賴校對規則 (Collation)
效能模擬不足：無法模擬真實資料庫的效能瓶頸或索引問題

3. 資料庫特定功能

InMemory 模式無法測試：預存程序、Triggers、Views、外鍵約束、檢查約束、資料類型精確度、Concurrency Tokens 等。

結論：當需要驗證複雜交易邏輯、並發處理、資料庫特定行為時，應使用 Testcontainers 進行整合測試。

Testcontainers 核心概念

Testcontainers 是一個測試函式庫，提供輕量好用的 API 來啟動 Docker 容器，專門用於整合測試。

核心優勢

真實環境測試：使用真實資料庫，測試實際 SQL 語法與資料庫限制
環境一致性：確保測試環境與正式環境使用相同服務版本
清潔測試環境：每個測試有獨立乾淨的環境，容器自動清理
簡化開發環境：開發者只需 Docker，不需安裝各種服務

必要套件

<ItemGroup>
  <!-- 測試框架 -->
  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
  <PackageReference Include="xunit" Version="2.9.3" />
  <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />
  <PackageReference Include="AwesomeAssertions" Version="9.4.0" />

  <!-- Testcontainers 核心套件 -->
  <PackageReference Include="Testcontainers" Version="4.11.0" />

  <!-- 資料庫容器 -->
  <PackageReference Include="Testcontainers.PostgreSql" Version="4.11.0" />
  <PackageReference Include="Testcontainers.MsSql" Version="4.11.0" />

  <!-- Entity Framework Core -->
  <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.0" />
  <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="9.0.0" />
  <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.0" />

  <!-- Dapper (可選) -->
  <PackageReference Include="Dapper" Version="2.1.72" />
  <PackageReference Include="Microsoft.Data.SqlClient" Version="7.0.0" />
</ItemGroup>

重要：使用 Microsoft.Data.SqlClient 而非舊版 System.Data.SqlClient，提供更好的效能與安全性。

環境需求

Windows 10 版本 2004+，啟用 WSL 2，8GB RAM（建議 16GB+），64GB 磁碟空間
Docker Desktop 建議設定：Memory 6GB、CPUs 4 cores、Swap 2GB、Disk 64GB

Read the full file on GitHub · 181 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

6d ago First seen · 181 lines · 199 tokens per session scan A 77991bf44e70

Subscribe to this mod's changes

dotnet-testing-advanced-testcontainers-database is a skill published in the GitHub repository kevintsengtw/dotnet-testing-agent-skills (28 stars, last pushed 21d ago), licensed MIT. It adds 199 tokens to every session and 2,553 once invoked, about $0.0010 per session on Opus 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 2026-08-30.

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