Select Files & Types

Constago filters input in stages: files, structs, then fields.

Select files

input.dir is the root for glob matching. Include patterns add files, and exclude patterns remove them.

input:
  dir: "."
  include:
    - "**/*.go"
    - "internal/model/*.go"
    - "package:domain"
  exclude:
    - "**/*_test.go"
    - "**/testdata/*.go"
    - "package:fixtures"

Patterns support recursive ** globs. A package:NAME selector walks input.dir, parses Go package clauses, and selects files whose declared package name equals NAME.

Exclude the configured output filename explicitly so later runs do not scan previously generated code:

input:
  exclude:
    - "**/*_test.go"
    - "**/constago.gen.go"

Select structs

By default, exported structs are selected. Unexported structs are skipped unless include_unexported is true or the struct has an include directive.

input:
  struct:
    explicit: false
    include_unexported: false
    only: "^(User|Account)$"
    except: "DTO$"

• only is a regular-expression allowlist.
• except is a regular-expression denylist applied after only.
• explicit: true requires an include directive.

Put directives immediately above a type declaration:

//constago:include
type internalRecord struct {
  ID string
}

// constago:exclude
type GeneratedDTO struct {
  ID string
}

An include directive can select an unexported struct even when include_unexported is false. An exclude directive always wins. A struct with both directives is skipped and recorded as a scan error.

Select fields

By default, exported named fields are selected. Use the constago struct tag for per-field control:

type User struct {
  ID       string `json:"id"`
  Password string `json:"password" constago:"exclude"`
  internal string `json:"internal" constago:"include"`
}

input:
  field:
    explicit: false
    include_unexported: false
    only: "^(ID|Name|Email)$"
    except: "Password$"

constago:"exclude" always excludes a field. constago:"include" includes it before exported-name and regex checks.

With field.explicit: true, fields need a constago tag. In practice, use constago:"include" on selected fields:

type User struct {
  ID   string `json:"id" constago:"include"`
  Name string `json:"name"`
}

Anonymous embedded fields are ignored and do not produce elements or getters.