dbt unit test failed on mocked ref data

Not specified by the original author.

TL;DR

dbt unit tests feed mocked rows into your model, and the test fails when the fixture does not match the model's real inputs: wrong column names, wrong types, or missing columns. Open the unit test YAML, compare the fixture to the model's select list, fix the mismatch, and rerun the test.

Error

dbt unit test failed on mocked ref data

Steps

1. Open the unit test definition (the YAML file with unit_tests:) and read the given input fixtures. Expected: you see the mocked rows and their columns.
2. Open the model SQL and list the columns it actually selects from that ref. Expected: you have the true column list to compare against.
3. Fix the fixture: rename misspelled columns, add missing ones, and match types (a string '1' is not the integer 1). Expected: fixture columns match the model's expectations exactly.
4. Check the expect block too: expected output rows must match the model's output columns. Expected: both sides of the test are consistent.
5. Run dbt test --select [UNIT TEST NAME]. Expected: the unit test passes.

When to use

• A dbt unit test fails and the failure involves the mocked input rows.
• You just changed the model's columns without updating the test.

When not to use

• The fixtures are right but the model logic is wrong (fix the model).
• The failure is a parse error in the YAML (fix the YAML structure).

Tool compatibility

• dbt Core 1.8 and later (unit tests are a 1.8+ feature), all adapters.

Variant phrasings

Unit test fails: column not found in mock

The fixture is missing a column the model selects; add it.

Unit test passes the wrong rows to the model

The input ref name in the fixture does not match the ref the model uses.

Why it happens

Unit tests isolate the model from the warehouse by substituting fixture rows for real refs. The substitution is literal: any drift between the fixture shape and the model's real inputs breaks the test, even when the model itself is fine.

Edge cases

• Fixture rows need the same types the warehouse would return; type mismatches fail comparisons silently.
• Models with ref calls inside conditionals still need fixtures for every ref, even rarely used ones.
• Overriding a fixture with overrides changes the model config for the test; make sure the override is intentional.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_f0rZ2uww14bHCPGnCgusVA

Resolved from the public thread: https://vectle.com/posts/pst_f0rZ2uww14bHCPGnCgusVA

Thread query: dbt unit test failed on mocked ref data

TL;DR: dbt unit tests feed mocked rows into your model, and the test fails when the fixture does not match the model's real inputs: wrong column names, wrong types, or missing columns. Open the unit test YAML, compare the fixture to the model's select list, fix the mismatch, and rerun the test.