node to page: Make Kind a string

Having a custom string type isn't worth it when it doesn't work
with `where`, `eq` etc.

Fixes #2689
Updates #2297

7 files changed, 58 insertions, 62 deletions

diff --git a/hugolib/hugo_sites.go b/hugolib/hugo_sites.go
index 0783f47ce..78137f6c1 100644
--- a/hugolib/hugo_sites.go
+++ b/hugolib/hugo_sites.go
@@ -192,7 +192,7 @@ func (h *HugoSites) renderCrossSitesArtifacts() error {
 func (h *HugoSites) assignMissingTranslations() error {
 	// This looks heavy, but it should be a small number of nodes by now.
 	allPages := h.findAllPagesByNodeTypeNotIn(KindPage)
-	for _, nodeType := range []Kind{KindHome, KindSection, KindTaxonomy, KindTaxonomyTerm} {
+	for _, nodeType := range []string{KindHome, KindSection, KindTaxonomy, KindTaxonomyTerm} {
 		nodes := h.findPagesByNodeTypeIn(nodeType, allPages)
 
 		// Assign translations
@@ -304,7 +304,7 @@ func (h *HugoSites) createMissingPages() error {
 
 // TODO(bep) np move
 // Move the new* methods after cleanup in site.go
-func (s *Site) newNodePage(typ Kind) *Page {
+func (s *Site) newNodePage(typ string) *Page {
 	return &Page{
 		Kind: typ,
 		Node: Node{
@@ -566,19 +566,19 @@ func (s *Site) updateBuildStats(page *Page) {
 }
 
 // TODO(bep) np remove
-func (h *HugoSites) findAllPagesByNodeType(n Kind) Pages {
+func (h *HugoSites) findAllPagesByNodeType(n string) Pages {
 	return h.Sites[0].findAllPagesByNodeType(n)
 }
 
-func (h *HugoSites) findPagesByNodeTypeNotIn(n Kind, inPages Pages) Pages {
+func (h *HugoSites) findPagesByNodeTypeNotIn(n string, inPages Pages) Pages {
 	return h.Sites[0].findPagesByNodeTypeNotIn(n, inPages)
 }
 
-func (h *HugoSites) findPagesByNodeTypeIn(n Kind, inPages Pages) Pages {
+func (h *HugoSites) findPagesByNodeTypeIn(n string, inPages Pages) Pages {
 	return h.Sites[0].findPagesByNodeTypeIn(n, inPages)
 }
 
-func (h *HugoSites) findAllPagesByNodeTypeNotIn(n Kind) Pages {
+func (h *HugoSites) findAllPagesByNodeTypeNotIn(n string) Pages {
 	return h.findPagesByNodeTypeNotIn(n, h.Sites[0].AllPages)
 }
 
diff --git a/hugolib/node.go b/hugolib/node.go
index 87ca6b726..21bdbba5b 100644
--- a/hugolib/node.go
+++ b/hugolib/node.go
@@ -291,7 +291,7 @@ func sectionsFromFilename(filename string) []string {
 }
 
 // TODO(bep) np node identificator
-func nodeTypeFromFilename(filename string) Kind {
+func kindFromFilename(filename string) string {
 	if !strings.Contains(filename, "_index") {
 		return KindPage
 	}
diff --git a/hugolib/page.go b/hugolib/page.go
index 698725635..73924587b 100644
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -49,53 +49,35 @@ var (
 	cjk = regexp.MustCompile(`\p{Han}|\p{Hangul}|\p{Hiragana}|\p{Katakana}`)
 )
 
-// Kind is the discriminator that identifies the different page types
-// in the different page collections. This can, as an example, be used
-// to to filter regular pages, find sections etc.
-// NOTE: THe exported constants below are used to filter pages from
-// templates in the wild, so do not change the values!
-type Kind string
-
 const (
-	KindPage Kind = "page"
+	KindPage = "page"
 
 	// The rest are node types; home page, sections etc.
-	KindHome         Kind = "home"
-	KindSection      Kind = "section"
-	KindTaxonomy     Kind = "taxonomy"
-	KindTaxonomyTerm Kind = "taxonomyTerm"
+	KindHome         = "home"
+	KindSection      = "section"
+	KindTaxonomy     = "taxonomy"
+	KindTaxonomyTerm = "taxonomyTerm"
 
 	// Temporary state.
-	kindUnknown Kind = "unknown"
+	kindUnknown = "unknown"
 
 	// The following are (currently) temporary nodes,
 	// i.e. nodes we create just to render in isolation.
-	kindSitemap   Kind = "sitemap"
-	kindRobotsTXT Kind = "robotsTXT"
-	kind404       Kind = "404"
+	kindSitemap   = "sitemap"
+	kindRobotsTXT = "robotsTXT"
+	kind404       = "404"
 )
 
-// IsNode returns whether this is an item of one of the list types in Hugo,
-// i.e. not a regular content page.
-func (k Kind) IsNode() bool {
-	return k != KindPage
-}
-
-// IsHome returns whether this is the home page.
-func (k Kind) IsHome() bool {
-	return k == KindHome
-}
-
-// IsPage returns whether this is a regular content page.
-func (k Kind) IsPage() bool {
-	return k == KindPage
-}
-
 type Page struct {
 
+	// Kind is the discriminator that identifies the different page types
+	// in the different page collections. This can, as an example, be used
+	// to to filter regular pages, find sections etc.
 	// Kind will, for the pages available to the templates, be one of:
 	// page, home, section, taxonomy and taxonomyTerm.
-	Kind
+	// It is of string type to make it easy to reason about in
+	// the templates.
+	Kind string
 
 	// Since Hugo 0.18 we got rid of the Node type. So now all pages are ...
 	// pages (regular pages, home page, sections etc.).
@@ -171,6 +153,22 @@ type Page struct {
 	site *Site
 }
 
+// IsNode returns whether this is an item of one of the list types in Hugo,
+// i.e. not a regular content page.
+func (p *Page) IsNode() bool {
+	return p.Kind != KindPage
+}
+
+// IsHome returns whether this is the home page.
+func (p *Page) IsHome() bool {
+	return p.Kind == KindHome
+}
+
+// IsPage returns whether this is a regular content page.
+func (p *Page) IsPage() bool {
+	return p.Kind == KindPage
+}
+
 type Source struct {
 	Frontmatter []byte
 	Content     []byte
@@ -485,7 +483,7 @@ func (p *Page) getRenderingConfig() *helpers.Blackfriday {
 
 func newPage(filename string) *Page {
 	page := Page{
-		Kind:         nodeTypeFromFilename(filename),
+		Kind:         kindFromFilename(filename),
 		contentType:  "",
 		Source:       Source{File: *source.NewFile(filename)},
 		Node:         Node{Keywords: []string{}, Sitemap: Sitemap{Priority: -1}},
@@ -1378,7 +1376,7 @@ func (p *Page) updatePageDates() {
 	// TODO(bep) np there is a potential issue with page sorting for home pages
 	// etc. without front matter dates set, but let us wrap the head around
 	// that in another time.
-	if !p.Kind.IsNode() {
+	if !p.IsNode() {
 		return
 	}
 
diff --git a/hugolib/page_collections.go b/hugolib/page_collections.go
index 4d29f23e0..84e77bdd7 100644
--- a/hugolib/page_collections.go
+++ b/hugolib/page_collections.go
@@ -61,11 +61,11 @@ func newPageCollectionsFromPages(pages Pages) *PageCollections {
 
 // TODO(bep) np clean and remove finders
 
-func (c *PageCollections) findPagesByNodeType(n Kind) Pages {
+func (c *PageCollections) findPagesByNodeType(n string) Pages {
 	return c.findPagesByNodeTypeIn(n, c.Pages)
 }
 
-func (c *PageCollections) getPage(typ Kind, path ...string) *Page {
+func (c *PageCollections) getPage(typ string, path ...string) *Page {
 	pages := c.findPagesByNodeTypeIn(typ, c.Pages)
 
 	if len(pages) == 0 {
@@ -94,11 +94,11 @@ func (c *PageCollections) getPage(typ Kind, path ...string) *Page {
 	return nil
 }
 
-func (c *PageCollections) findIndexNodesByNodeType(n Kind) Pages {
+func (c *PageCollections) findIndexNodesByNodeType(n string) Pages {
 	return c.findPagesByNodeTypeIn(n, c.indexPages)
 }
 
-func (*PageCollections) findPagesByNodeTypeIn(n Kind, inPages Pages) Pages {
+func (*PageCollections) findPagesByNodeTypeIn(n string, inPages Pages) Pages {
 	var pages Pages
 	for _, p := range inPages {
 		if p.Kind == n {
@@ -108,7 +108,7 @@ func (*PageCollections) findPagesByNodeTypeIn(n Kind, inPages Pages) Pages {
 	return pages
 }
 
-func (*PageCollections) findPagesByNodeTypeNotIn(n Kind, inPages Pages) Pages {
+func (*PageCollections) findPagesByNodeTypeNotIn(n string, inPages Pages) Pages {
 	var pages Pages
 	for _, p := range inPages {
 		if p.Kind != n {
@@ -118,11 +118,11 @@ func (*PageCollections) findPagesByNodeTypeNotIn(n Kind, inPages Pages) Pages {
 	return pages
 }
 
-func (c *PageCollections) findAllPagesByNodeType(n Kind) Pages {
+func (c *PageCollections) findAllPagesByNodeType(n string) Pages {
 	return c.findPagesByNodeTypeIn(n, c.Pages)
 }
 
-func (c *PageCollections) findRawAllPagesByNodeType(n Kind) Pages {
+func (c *PageCollections) findRawAllPagesByNodeType(n string) Pages {
 	return c.findPagesByNodeTypeIn(n, c.rawAllPages)
 }
 
diff --git a/hugolib/page_test.go b/hugolib/page_test.go
index 7792be3dc..8530759d6 100644
--- a/hugolib/page_test.go
+++ b/hugolib/page_test.go
@@ -1278,17 +1278,15 @@ func TestIndexPageSimpleMethods(t *testing.T) {
 	}
 }
 
-func TestPageType(t *testing.T) {
+func TestKind(t *testing.T) {
 
 	// Add tests for these constants to make sure they don't change
-	require.Equal(t, Kind("page"), KindPage)
-	require.Equal(t, Kind("home"), KindHome)
-	require.Equal(t, Kind("section"), KindSection)
-	require.Equal(t, Kind("taxonomy"), KindTaxonomy)
-	require.Equal(t, Kind("taxonomyTerm"), KindTaxonomyTerm)
-
-	require.False(t, KindPage.IsNode())
-	require.True(t, KindHome.IsNode())
+	require.Equal(t, "page", KindPage)
+	require.Equal(t, "home", KindHome)
+	require.Equal(t, "section", KindSection)
+	require.Equal(t, "taxonomy", KindTaxonomy)
+	require.Equal(t, "taxonomyTerm", KindTaxonomyTerm)
+
 }
 
 func TestChompBOM(t *testing.T) {
diff --git a/hugolib/pagination.go b/hugolib/pagination.go
index c1f19212d..3e3bb59c6 100644
--- a/hugolib/pagination.go
+++ b/hugolib/pagination.go
@@ -260,7 +260,7 @@ func splitPageGroups(pageGroups PagesGroup, size int) []paginatedElement {
 // Paginator gets this Node's paginator if it's already created.
 // If it's not, one will be created with all pages in Data["Pages"].
 func (n *Page) Paginator(options ...interface{}) (*Pager, error) {
-	if !n.Kind.IsNode() {
+	if !n.IsNode() {
 		return nil, fmt.Errorf("Paginators not supported for pages of type %q (%q)", n.Kind, n.Title)
 	}
 	pagerSize, err := resolvePagerSize(options...)
@@ -303,7 +303,7 @@ func (n *Page) Paginator(options ...interface{}) (*Pager, error) {
 // If it's not, one will be created with the qiven sequence.
 // Note that repeated calls will return the same result, even if the sequence is different.
 func (n *Page) Paginate(seq interface{}, options ...interface{}) (*Pager, error) {
-	if !n.Kind.IsNode() {
+	if !n.IsNode() {
 		return nil, fmt.Errorf("Paginators not supported for pages of type %q (%q)", n.Kind, n.Title)
 	}
 
diff --git a/hugolib/site.go b/hugolib/site.go
index e7f009ac7..c8d38b909 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -1561,7 +1561,7 @@ func (s *Site) assembleSections() {
 	}
 }
 
-func (s *Site) nodeTypeFromSections(sections []string) Kind {
+func (s *Site) nodeTypeFromSections(sections []string) string {
 	if _, isTaxonomy := s.Taxonomies[sections[0]]; isTaxonomy {
 		if len(sections) == 1 {
 			return KindTaxonomyTerm
@@ -1662,7 +1662,7 @@ func (s *Site) Stats() {
 // This will return nil when no page could be found.
 //
 // The valid page types are: home, section, taxonomy and taxonomyTerm
-func (s *SiteInfo) GetPage(typ Kind, path ...string) *Page {
+func (s *SiteInfo) GetPage(typ string, path ...string) *Page {
 	return s.getPage(typ, path...)
 }