How to make a test warn instead of fail in dbt (severity)

Not every failed test should stop a pipeline. A handful of orders with a strange status deserve a look, but the dashboards can still be built. severity: warn turns a test into a warning, and warn_if and error_if set thresholds, so a few bad rows warn and many bad rows fail.

Copy and paste

One test:

      - name: status
        data_tests:
          - accepted_values:
              arguments:
                values: ['placed', 'shipped', 'returned']
              config:
                severity: warn

Warn from one bad row, fail from six:

      - name: amount
        data_tests:
          - positive_value:
              config:
                warn_if: ">0"
                error_if: ">5"

Every test in a folder, in dbt_project.yml:

data_tests:
  shop:
    staging:
      +severity: warn

In a singular test file:

{{ config(severity='warn') }}
select ...

What the output looks like

WARN 1 positive_value_stg_orders_amount ..................... [WARN 1 in 0.01s]
[WARNING]: in test positive_value_stg_orders_amount (models/staging/_staging.yml)
[WARNING]: Got 1 result, configured to warn if >0
Done. PASS=5 WARN=1 ERROR=0 SKIP=0

How the settings combine

A test counts its failing rows and compares the count with two conditions:

• with severity: error, the default, dbt checks error_if first and then warn_if;
• with severity: warn, dbt checks only warn_if.

Both conditions default to !=0, so by default any failing row is an error. In the second example, one negative amount gives a warning and six give an error.

Warnings and dbt build

A failed test makes dbt build skip the models that depend on the tested model. A warning does not: the models downstream are built as usual, and the run ends with WARN=1 instead of ERROR=1. Use warnings for data you want to know about, not for data that would make the results wrong.

Turning warnings back into errors

In CI you may want every warning to fail the job:

dbt build --warn-error

--warn-error-options limits that to specific kinds of warnings.

Tested with dbt Core 1.12.