Data-driven Testing Using CSV and JSON Files

What Is Data-driven Testing?

Data-driven testing runs the same request multiple times, each time with a different set of input values pulled from an external file, instead of hardcoding values into the request.

Supported File Formats

FormatStructure
CSVColumn headers become variable names; each row is one iteration
JSONArray of objects; each object's keys become variable names

Using a Data File in the Runner

When starting a run in the Collection Runner, you can select a CSV or JSON file. Postman then runs the collection once per row/object, substituting the values wherever a matching variable is referenced.

Benefits

This approach lets you test many combinations of inputs - like different user accounts or product IDs - without duplicating requests or scripts.

Once data files are set up, scripts can read and act on that data during each iteration - let's look at how to iterate over data files in tests.

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