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title: You don't need the base app to run your unit tests
summary: Unit tests for self-contained Business Central logic do not require the base application to run. By structuring code as isolated sub-extensions with their own app.json files and only platform dependencies, developers can significantly reduce container startup time and pipeline costs.
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  - performance optimization
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    title: You don't need the base app to run your unit tests
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    title: You don't need the base app to run your unit tests
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    quote: If your tests are truly testing a unit, they should not need the entire application stack as their environment.
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    title: You don't need the base app to run your unit tests
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    quote: Eight minutes down to under two is not a marginal improvement. It changes how often you run tests and how fast you can iterate.
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post_id: https://stefanmaron.com/posts/unittestswithoutbaseapp/
source_id: stefanmaron-com
source_name: Stefan Maron
url: https://stefanmaron.com/posts/unittestswithoutbaseapp/
published_at: "2026-05-24T22:00:00.000Z"
author: Stefan Maron
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words: 850
quotes:
  - text: If your tests are truly testing a unit, they should not need the entire application stack as their environment.
    why_it_matters: This principle establishes why isolated testing is both valid and efficient - it's fundamental to unit test philosophy
  - text: Eight minutes down to under two is not a marginal improvement. It changes how often you run tests and how fast you can iterate.
    why_it_matters: Quantifies the practical benefit, showing that performance gains directly impact development workflow and feedback loops
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---

# You don't need the base app to run your unit tests

[Read the post](https://stefanmaron.com/posts/unittestswithoutbaseapp/) · Stefan Maron (Stefan Maron, MVP) · 2026-05-24 · 850 words · tier community · reviewed (checked by Opus)

> Unit tests for self-contained Business Central logic do not require the base application to run. By structuring code as isolated sub-extensions with their own app.json files and only platform dependencies, developers can significantly reduce container startup time and pipeline costs.

## Key points

- Isolate business logic and its tests in sub-extensions with no application dependency, only platform dependency
- Use nested app.json files as compilation scopes - the AL compiler picks up only the app.json at the root folder it targets
- Deploy isolated sub-extensions to containers without the base app to match test scope with environment scope
- Test pipeline execution time reduced from 8 minutes to under 2 minutes by eliminating unnecessary base app overhead
- This pattern mirrors Microsoft's own application stack structure but requires code to be architected for isolation from the start

## Quotes

- "If your tests are truly testing a unit, they should not need the entire application stack as their environment." (This principle establishes why isolated testing is both valid and efficient - it's fundamental to unit test philosophy)
- "Eight minutes down to under two is not a marginal improvement. It changes how often you run tests and how fast you can iterate." (Quantifies the practical benefit, showing that performance gains directly impact development workflow and feedback loops)

## Context

- Features: sub-extension compilation, isolated test environments, base app removal, container configuration, pipeline optimization
- Versions: 27, 28

Source: Stefan Maron, community blog. Summary, key points and quotes are derived (CONTENT-NOTICE.md); read the original for the full text.