convy/internal/check/suite.go

package check

import (
	"regexp"
	"sort"

	"git.vakhrushev.me/av/convy/internal/manifest"
	"git.vakhrushev.me/av/convy/internal/suite"
)

// Suite runs every check of a suite and returns the report.
func Suite(s *suite.Suite) *Report {
	rep := &Report{}
	checkManifest(s, rep)
	checkTopicNames(s, rep)
	checkBaseLayers(s, rep)
	checkSelfGoverning(s, rep)

	for _, d := range s.Docs {
		checkForm(s, d, rep)
		checkLinks(s, d, rep)
		if d.Front.Topic != "" {
			checkSpread(s, d, rep)
		}
	}
	return rep
}

// checkManifest checks the manifest itself: the shape of prefixes, live and
// retired not overlapping, the declared files being present and no undeclared
// ones lying around.
func checkManifest(s *suite.Suite, rep *Report) {
	m := s.Manifest

	for _, key := range m.Undecoded {
		rep.Warnf(Manifest, manifest.Name, 0, "the key %s is unknown to the tool", key)
	}
	for _, name := range []string{m.Language.Description, m.Language.Reading} {
		if name != "" && !s.Exists(name) {
			rep.Errorf(Manifest, manifest.Name, 0, "the [language] section declares the document %q, and the file is missing", name)
		}
	}

	byPath := make(map[string][]string)
	for _, prefix := range m.LivePrefixes() {
		if err := manifest.ValidPrefix(prefix); err != nil {
			rep.Errorf(Manifest, manifest.Name, 0, "%s", err)
		}
		if m.PrefixRetired(prefix) {
			rep.Errorf(Manifest, manifest.Name, 0,
				"prefix %s is listed both live and retired: a retired one is never reissued", prefix)
		}
		path := m.Prefixes.Live[prefix]
		byPath[path] = append(byPath[path], prefix)
	}
	for _, path := range sortedKeys(byPath) {
		if prefixes := byPath[path]; len(prefixes) > 1 {
			sort.Strings(prefixes)
			rep.Errorf(Manifest, manifest.Name, 0,
				"the file %q has several prefixes declared for it (%v): a prefix belongs to one file", path, prefixes)
		}
	}
	for prefix := range m.Prefixes.Retired {
		if err := manifest.ValidPrefix(prefix); err != nil {
			rep.Errorf(Manifest, manifest.Name, 0, "among the retired ones: %s", err)
		}
	}

	for _, prefix := range sortedKeys(s.Missing) {
		rep.Errorf(Manifest, manifest.Name, 0,
			"prefix %s is assigned to the file %q, which the suite does not hold", prefix, s.Missing[prefix])
	}
	for _, path := range s.Unregistered {
		rep.Errorf(Manifest, path, 1,
			"the file is written in the conventions language yet not declared in the suite manifest: for the suite it does not exist")
	}
	for _, err := range s.Broken {
		rep.Errorf(Manifest, manifest.Name, 0, "%s", err)
	}

	for _, topic := range m.LiveTopics() {
		if m.TopicRetired(topic) {
			rep.Errorf(Manifest, manifest.Name, 0,
				"topic %q is listed both live and retired", topic)
		}
		if len(s.Layers(topic)) == 0 {
			rep.Errorf(Manifest, manifest.Name, 0,
				"topic %q is declared live while the suite holds no layer of it: a topic lives as long as at least one layer does", topic)
		}
	}
}

var (
	// topicNameRe is the hard bound: a topic name reaches the file system of
	// a consumer, so it has to be usable as a file name — Latin letters,
	// digits and the plain separators.
	topicNameRe = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9._-]*$`)
	// kebabRe is the recommended shape, and only a recommendation.
	kebabRe = regexp.MustCompile(`^[a-z0-9]+(-[a-z0-9]+)*$`)
)

// checkTopicNames checks the shape of topic names. A name lands both in a
// consumer's file system and in their manifest, which is where the hard bound
// comes from; lower kebab-case on top of that is a recommendation and speaks as
// a warning.
func checkTopicNames(s *suite.Suite, rep *Report) {
	for _, topic := range s.Manifest.LiveTopics() {
		switch {
		case !topicNameRe.MatchString(topic):
			rep.Errorf(Manifest, manifest.Name, 0,
				"the topic name %q is not usable as a file name: a name is written in Latin letters and travels into the file system of a consumer", topic)
		case !kebabRe.MatchString(topic):
			rep.Warnf(Manifest, manifest.Name, 0,
				"the topic name %q is not lower kebab-case, which is the recommended shape", topic)
		}
	}
}

// checkSelfGoverning guards the document without a topic.
//
// A topic-less document is the one the suite governs itself by: it travels
// nowhere and cannot be subscribed to, so it gets no spread checks. Nothing in
// the manifest tells it from a convention that lost its topic key, and the
// silent loss is the expensive one — the file keeps every check of form while
// quietly dropping every check about travelling to a consumer. Two markers make
// that loss visible: such a document is one per suite, and it has no layer of
// its own, hence neither axis keys nor a base.
func checkSelfGoverning(s *suite.Suite, rep *Report) {
	var topicless []string
	for _, d := range s.Docs {
		if d.Front.Topic != "" {
			continue
		}
		topicless = append(topicless, d.Path)

		if d.Front.Axis() || d.Front.Extends != "" {
			rep.Errorf(Manifest, d.Path, d.Front.At["prefix"],
				"the file declares no topic yet carries the keys of a layer: a document without a topic is the one the suite governs itself by, and it is nobody's layer — the topic key looks lost")
		}
	}
	if len(topicless) > 1 {
		sort.Strings(topicless)
		for _, path := range topicless[1:] {
			rep.Errorf(Manifest, path, 1,
				"the suite holds more than one document without a topic (%v): only the one the suite governs itself by may lack a topic, so the rest have lost the key",
				topicless)
		}
	}
}

// checkBaseLayers checks that a topic holds no more than one layer without axis
// keys. The base layer is the only one of its kind: it reaches every copy, and a
// second such layer would mean two base texts in one assembled file.
func checkBaseLayers(s *suite.Suite, rep *Report) {
	for _, topic := range s.Manifest.LiveTopics() {
		var base []string
		for _, d := range s.Layers(topic) {
			if !d.Front.Axis() {
				base = append(base, d.Path)
			}
		}
		if len(base) > 1 {
			sort.Strings(base)
			for _, path := range base[1:] {
				rep.Errorf(Spread, path, 1,
					"topic %q holds more than one layer without axis keys: the base layer is the only one of its kind, and the candidates are %v",
					topic, base)
			}
		}
	}
}

func sortedKeys[V any](m map[string]V) []string {
	keys := make([]string, 0, len(m))
	for k := range m {
		keys = append(keys, k)
	}
	sort.Strings(keys)
	return keys
}