Function checkVideoReferenceImages

internal/attachments/references.go:187–204

checkVideoReferenceImages returns an error naming every video the markdown embeds through a reference definition. Rewriting one would produce an image embed of a video, which renders as a broken image.

(refs []attachmentRef, attachmentArgs []attachmentArg)

// embeds through a reference definition. Rewriting one would produce an image
// embed of a video, which renders as a broken image.
func checkVideoReferenceImages(refs []attachmentRef, attachmentArgs []attachmentArg) error {
	var paths []string
	seen := map[int]bool{}
	for _, r := range refs {
		if !r.referenceStyle() || !r.isEmbed {
			continue
		}
		if !attachmentArgs[r.attachmentArg].RendersAsPlayer || seen[r.attachmentArg] {
			continue
		}
		seen[r.attachmentArg] = true
		paths = append(paths, attachmentArgs[r.attachmentArg].Path)
	}
	if len(paths) == 0 {
		return nil
	}
	return fmt.Errorf("cannot embed a video as a reference-style image: %s", strings.Join(paths, ", "))
}

// attachmentRef is one markdown reference to an attached file: the markdown
// half of this package, paired to an argument by attachmentArgForDestination.