---
title: "Test Power BI"
description: "What CAT can test in Power BI — a file open in Power BI Desktop, a semantic model in a workspace — how to set it up, and which tests pay off"
url: "https://docs.justcat.it/how-to-guides/data-platforms/power-bi/test-power-bi/"
---
# Test Power BI


## What you can test

| Where the model is | Provider | Guide |
|---|---|---|
| A `.pbix` or `.pbip` file open in **Power BI Desktop** on your machine | [PowerBI@2](https://docs.justcat.it/reference/data-sources/providers/powerbi-2/ "PowerBI@2") — the open file's name is the whole connection | [Test a Power BI Desktop file](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/test-a-power-bi-desktop-file/ "Test a Power BI Desktop file") |
| A **semantic model published to a workspace** — Power BI or Microsoft Fabric | [Dax@2](https://docs.justcat.it/reference/data-sources/providers/dax-2/ "Dax@2") over the workspace's XMLA endpoint | [Test a semantic model in a workspace](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/test-a-semantic-model-in-a-workspace/ "Test a semantic model in a workspace") |
| A tabular model in **Azure Analysis Services** or **SQL Server Analysis Services** | [Dax@2](https://docs.justcat.it/reference/data-sources/providers/dax-2/ "Dax@2") | the same guide — only the connection string differs |

In every case the test's query is **DAX**, not SQL — a tabular model does not speak SQL. You need a little DAX, and there are three easy ways to get the query you need without writing it: [Get the DAX query behind a visual](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/get-the-dax-query-behind-a-visual/ "Get the DAX query behind a visual"). [DAX for SQL people](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/sql-to-dax/ "DAX for SQL people") covers the rest.

## Set it up in CAT Studio

The quickest way to a working Power BI data source is CAT Studio: **Data sources → New data source**, pick the technology — *Power BI Desktop*, *Power BI Semantic Model*, *MS Fabric Semantic Model*, *Azure Analysis Services*, *SQL Server Analysis Services* — and the dialog asks for exactly the values that technology needs (the open file's name; the workspace, the model, the service principal) and writes the connection string for you. On the **Tests** page the query editor runs DAX against it, so you see the result of your query before you wrap an expectation around it. [CAT Pilot](https://docs.justcat.it/reference/cat-studio/cat-pilot/ "CAT Pilot") — Studio's AI assistant — writes the DAX for you from a sentence, and turns a query into a named, described, tagged test.

Everything Studio writes is an ordinary project file, so the same tests run from the command line and in pipelines. Without Studio, the two guides above show the YAML.

## Which tests pay off

A Power BI model is a copy of data that lives somewhere else, shaped by measures someone wrote. The tests worth having check exactly those two things:

* **The model matches its source.** A `sets match` test with the DAX on one side and the SQL on the other — customers in the model against customers in the warehouse, sales per month in the model against sales per month in the source. This is the test only a tool that speaks both DAX and SQL can run, and it catches the refresh that did not happen, the filter somebody left in Power Query, the relationship that drops rows.
* **The measures are right.** Total sales from the measure against `SUM` from the warehouse, per year, with a [Tolerance](https://docs.justcat.it/reference/tests/tolerance/ "Tolerance") for rounding; a measure that must never be blank; the number a visual shows, taken straight from the report with Performance Analyzer, against the number the business expects. See [Test measures](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/test-measures/ "Test measures").
* **The model is complete.** Every dimension loaded (`set is not empty`), every expected member present, no orphan keys — smoke tests that take a minute to write and run on every refresh.

Test the file while you build it, test the published model on a schedule — the project file is the same; only the data source changes.

## Related

* [Test a Power BI Desktop file](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/test-a-power-bi-desktop-file/ "Test a Power BI Desktop file") · [Test a semantic model in a workspace](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/test-a-semantic-model-in-a-workspace/ "Test a semantic model in a workspace") · [Test measures](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/test-measures/ "Test measures")
* [Get the DAX query behind a visual](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/get-the-dax-query-behind-a-visual/ "Get the DAX query behind a visual") · [DAX for SQL people](https://docs.justcat.it/how-to-guides/data-platforms/power-bi/sql-to-dax/ "DAX for SQL people")
* [PowerBI@2](https://docs.justcat.it/reference/data-sources/providers/powerbi-2/ "PowerBI@2") · [Dax@2](https://docs.justcat.it/reference/data-sources/providers/dax-2/ "Dax@2") — the providers in the reference.