Testing this Resolver

Step 1: Understand what to test

Read the entry point code (cyan/index.ts or equivalent) to find:

• What input.config keys the resolver reads (e.g., config.strategy, config.preserveKeys)
• What resolution strategy it uses (last-wins, deep-merge, priority-based)
• How it uses FileOrigin (template name, layer number)

Step 2: Prepare input directories

Create separate directories for each template/layer's version of the conflicting file(s):

inputs/
└── deep-merge/
    ├── template-a/
    │   └── package.json
    └── template-b/
        └── package.json

Each directory contains the files as produced by that template/layer.

Step 3: Write test.cyan.yaml

Create a test.cyan.yaml file in the resolver root:

tests:
  - name: 'merge-two-files'
    expected:
      type: snapshot
      value:
        path: ./snapshots/merge-two-files
    resolver_inputs:
      - path: ./inputs/deep-merge/template-a
        origin:
          template: template-a
          layer: 0
      - path: ./inputs/deep-merge/template-b
        origin:
          template: template-b
          layer: 1
    config:
      strategy: deep-merge

resolver_inputs

Each entry specifies a directory path containing conflicting files and the origin metadata:

resolver_inputs:
  - path: ./inputs/deep-merge/template-a
    origin:
      template: template-a
      layer: 0
  - path: ./inputs/deep-merge/template-b
    origin:
      template: template-b
      layer: 1

• path: directory containing the template's files
• origin.template: which template produced these files (string)
• origin.layer: layer number (number, NOT string — do NOT quote it)

config

Keys must match the input.config keys your resolver actually reads. Extract them from the entry point code — do NOT invent fictional config keys.

expected

Declares expected resolved output using a snapshot path:

expected:
  type: snapshot
  value:
    path: ./snapshots/merge-two-files

Step 4: Run and iterate

# Run all resolver tests
cyanprint test resolver .

# Update snapshots after intentional changes
cyanprint test resolver . --update-snapshots

Commutativity Testing

Always include tests that verify the resolver produces the same output regardless of input order:

Note: There is no official commutativity checker. You must manually verify commutativity by writing tests with swapped input order that snapshot to the same output directory:

tests:
  - name: 'commutativity-order-1'
    expected:
      type: snapshot
      value:
        path: ./snapshots/commutative-result
    resolver_inputs:
      - path: ./inputs/commutative/template-a
        origin:
          template: template-a
          layer: 0
      - path: ./inputs/commutative/template-b
        origin:
          template: template-b
          layer: 1
    config:
      strategy: deep-merge

  - name: 'commutativity-order-2'
    expected:
      type: snapshot
      value:
        path: ./snapshots/commutative-result
    resolver_inputs:
      - path: ./inputs/commutative/template-b
        origin:
          template: template-b
          layer: 1
      - path: ./inputs/commutative/template-a
        origin:
          template: template-a
          layer: 0
    config:
      strategy: deep-merge

Both tests snapshot to the same commutative-result directory.

See reference.md for complete examples.