# `MishkaGervaz.Form.Verifiers.ValidateSource`
[🔗](https://github.com/mishka-group/mishka_gervaz/blob/v0.0.1-alpha.3/lib/mishka_gervaz/form/verifiers/validate_source.ex#L1)

Validates the `source` section of MishkaGervaz form DSL.

Ensures every required action (`create`, `update`, `read`) is defined
either on the resource or inherited from the domain — compilation fails
when both are nil. Resource overrides win when both are set.

The verifier short-circuits when no fields are declared (a form without
fields has no source to consume).

The `master_check` requirement is enforced upstream by
`MishkaGervaz.Form.Transformers.MergeDefaults.merge_master_check_default/1`,
which always persists a fallback MFA when neither resource nor domain
defines one — the verifier no longer guards that path.

See `MishkaGervaz.Form.Dsl.Source`,
`MishkaGervaz.Form.Transformers.MergeDefaults`,
`MishkaGervaz.Form.Verifiers.Helpers`, and sibling verifiers.

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*Consult [api-reference.md](api-reference.md) for complete listing*