[CT-1908] [Regression] exposure_content referenced incorrectly

[Mathyoub]

Is this a regression in a recent version of dbt-core?

• I believe this is a regression in dbt-core functionality
• I have searched the existing issues, and I could not find an existing issue for this regression

Current Behavior

local variable 'exposure_content' referenced before assignment error due to exposure_content being referenced instead of source_content

Expected/Previous Behavior

This is new in 1.4.0
dbt deps will not fail with error above

Steps To Reproduce

• you're doing state comparison (--state <old_manifest>)
  or
• your old project has sources defined in it (our automated test for cross-version state comparison compatibility does not include sources)

Relevant log output

see current behavior

Environment

- OS:
- Python:
- dbt (working version): 1.3.2
- dbt (regression version): 1.4.0

Which database adapter are you using with dbt?

No response

Additional Context

No response

[jtcohen6]

Specifically, this would affect any project with sources defined, that is doing a manifest comparison across v1.3 → v1.4. If their last dbt run was on v1.3 (or earlier), and they use a manifest from that run in a state:modified run with v1.4, they will run into this error.

This method exists to make that cross-version comparison possible. There was a bug in the method.

To catch this in the future, let's update this automated test to include a complex project, with more resource types: https://github.com/dbt-labs/dbt-core/blob/main/tests/functional/artifacts/test_previous_version_state.py