Contrary to documentation, loading a file from JSON performs validation

[benarena]

I noticed this when trying to load an ACH file from JSON using file.UnmarshalJSON.

The documentation states that the resulting file should be validated, as it may be invalid.

ach/file.go

Lines 98 to 103 in 85a464f

	// FileFromJSON attempts to return a *File object assuming the input is valid JSON.
	//
	// Callers should always check for a nil-error before using the returned file.
	//
	// The File returned may not be valid and callers should confirm with Validate().
	// Invalid files may be rejected by other Financial Institutions or ACH tools.

However, before returning a successful file, validation is called resulting in an error:

ach/file.go

Lines 166 to 168 in 85a464f

	if err := file.Validate(); err != nil {
	return file, err
	}

I'd like to be able to validate my parsed file on my own after unmarshalling from JSON, and preferably without duplicating the behavior already present. My recommendation is to remove the validation, or at a minimum, update the documentation to more specifically address the behavior of the function.

[adamdecaf]

I can see where removing this check helps to keep errors from unmarshaling and validation isolated. It'd need to be in a new minor release.

return file, err was meant to return the entire file even if Validation errors occurred, but it's non-trivial to detect which type of error was returned.