Compare effective values

Distinguish equal, changed, missing and unexpected keys.

Type: Build Languages: Go Stage: 3 of 4 Prerequisites: Basic functions, collections, JSON and the previous stages when applicable. Time: ~2 hours

What you build

Compare expected resolved values with the observed scalar map. Emit one sorted row per union key. A missing key is different from a present null. Evaluate equality before redacting so two different secret values still report changed.

Worked example

The effective timeout is 5 but observed timeout is 30, so kind is changed. api_token also changes, but both displayed values and every history value become [REDACTED]. region stays equal.

Implement the contract

Compare(in Input) Report returns schemaVersion:1, drift:boolean, and sorted changes. Each row has key, kind, expected, observed, history, redacted. Sensitive keys match password/secret/token/api-key/credential case-insensitively or the explicit sensitive list.

Reject malformed input before producing a partial artifact. The tests include held-out records separate from the demonstration fixture.

Run your work

python3 scripts/project_test.py configuration-drift-explainer --init /tmp/configuration-drift-explainer-work
python3 scripts/project_test.py configuration-drift-explainer --stage 3 --path /tmp/configuration-drift-explainer-work --strict

Initialization copies cumulative scaffolding without replacing your work. Implement the TODO functions in the first-stage starter; later-stage starter notes describe the new behavior. Tests import the learner workspace. Run the command in the README against your own input after passing the stage.

Inspect and extend

Add an explicit allowlist for a CI consumer that only considers selected drift rows blocking.

Go standard library and Node standard library. All fixtures and implementations are original.