Load named configuration layers

Reject ambiguous configuration before comparing environments.

Type: Build Languages: Go Stage: 1 of 4 Prerequisites: Basic functions, collections, JSON and the previous stages when applicable. Time: ~2 hours

What you build

Build Load for a one-MiB JSON object containing ordered layers, required observed, and optional sensitive exact key names. Layer names must be unique. This tool uses flat, scalar keys; flatten nested configurations explicitly before use.

Worked example

The fixture declares timeout 30 in defaults.json, then timeout 5 in env:TIMEOUT. Both values survive input parsing. A nested timeout object is rejected because this contract does not imply a deep-merge policy.

Implement the contract

Load(data []byte) (Input, error) returns typed Layer{Name, Values} records. Reject unknown top-level/layer fields, trailing JSON, null maps, duplicate names and blank keys. Scalars may be null, string, boolean or number.

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 1 --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 a separate JSON-flattening adapter and specify whether arrays should be atomic values.

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