map-diff

$map diff

Trace the downstream impact of staged git changes using the committed coco-map.json. Shows which other functions, evaluation sets, and capability definitions are affected before the commit lands.

Preconditions

• .cocoplus/ must be initialized
• .cocoplus/map/coco-map.json must exist (run $map first)
• Staged git changes must exist (git diff --staged must be non-empty)

Step-by-Step Behavior

1. Verify initialization: Check .cocoplus/ exists. If not, output: "CocoPlus not initialized. Run $pod init first." and exit.

2. Verify map exists: Check .cocoplus/map/coco-map.json exists. If not, output:

   No function knowledge graph found. Run $map first to build it.
   

   and exit.

3. Read staged changes: Run git diff --staged --name-only to get the list of staged files.

   • If no staged changes, output: "No staged changes found. Stage changes with git add before running $map diff." and exit.

4. Read coco-map.json: Load the structural dependency graph from coco-map.json.

5. Identify modified functions: For each staged file path, check if any function in coco-map.json has a matching file path. Collect the set of modified functions.

6. Trace downstream dependents: For each modified function, traverse the dependency graph in coco-map.json:

   • Find all functions that list the modified function as a dependency (direct dependents)
   • Find their dependents (transitive — stop at 5 hops)
   • Collect the full impact set

7. Check shared evaluation sets: Identify whether any modified function shares an evaluation set with other functions. If so, those other functions are also affected — they may produce different results after the change.

8. Check capability definitions: Identify whether the modified functions belong to any named business capabilities in the domain section. If a capability definition changes, note it.

9. Build impact report and display:

CocoMap Impact Analysis — [timestamp]
Staged files: [N]

Modified functions: [N]
  - [function-name] ([file-path])
  - ...

Downstream impact:
  Direct dependents: [N]
    - [dependent-function] — depends on [modified-function] via [dependency-type]
  Transitive dependents (up to 5 hops): [N]
    - [transitive-function] — [hop-count] hops from modified

Shared evaluation sets affected:
  - [eval-set-name] — also used by [other-functions] (those evaluations may produce different results)
  [or: "None"]

Business capabilities affected:
  - [capability-name]: [description of what changes]
  [or: "None"]

Gaps surfaced:
  - [any new gaps the change would introduce, e.g. adding a dependency on an unevaluated function]
  [or: "None"]

Recommendation: [brief summary of what to review before committing]