go-bananas/internal/seed/consolidated_test.go

package seed_test

import (
	"strings"
	"testing"

	"github.com/urpi/go-bananas/internal/domain"
	"github.com/urpi/go-bananas/internal/seed"
	"github.com/urpi/go-bananas/internal/tokenengine"
)

// TestGoTellSlugsAreSeeded is the one that matters for adoption.
//
// go-tell's theme switcher offers cyberpunk, nordic, obsidian and terminal, and its
// stylesheet keys on html[data-theme="<slug>"]. If any of those slugs is missing from
// the service, selecting it sets an attribute that resolves to nothing and the
// application falls back to whichever rule happens to match last. That is invisible in
// a smoke test and obvious to a user, so it is asserted here.
func TestGoTellSlugsAreSeeded(t *testing.T) {
	want := []string{"cyberpunk", "nordic", "obsidian", "terminal"}

	have := map[string]bool{}
	for _, slug := range seed.Slugs() {
		have[slug] = true
	}

	for _, slug := range want {
		if !have[slug] {
			t.Errorf("go-tell's %q palette is not seeded, so selecting it would do nothing", slug)
		}
	}
}

// TestEveryConsolidatedPaletteResolvesInBothAppearances is the property the contract
// depends on, and it is expressed through the engine rather than through the token
// document's shape.
//
// The shape is deliberately not the assertion. In this schema the base document *is*
// the light scheme and `$appearances` carries only the dark override, so a theme with
// both schemes still has one key under `$appearances`. What matters is that resolving
// a consolidated palette in each appearance yields a different background, which is
// what makes the appearance control do anything at all.
func TestEveryConsolidatedPaletteResolvesInBothAppearances(t *testing.T) {
	for _, def := range seed.All() {
		if !strings.Contains(def.Description, "go-") {
			continue // an original go-bananas theme, not a consolidated one
		}

		theme := def.Theme()
		light := tokenengine.Resolve(theme, domain.AppearanceLight)
		dark := tokenengine.Resolve(theme, domain.AppearanceDark)

		read := func(doc *tokenengine.Doc, path string) string {
			token, ok := doc.Lookup(path)
			if !ok {
				return ""
			}
			return token.CSS
		}

		lightBg := read(light, "color.semantic.background")
		darkBg := read(dark, "color.semantic.background")

		if lightBg == "" || darkBg == "" {
			t.Errorf("%s does not resolve a background in both appearances (light=%q dark=%q)",
				def.Slug, lightBg, darkBg)
			continue
		}
		if lightBg == darkBg {
			t.Errorf("%s resolves the same background in both appearances (%s), "+
				"so the appearance control would do nothing for it", def.Slug, lightBg)
		}

		// Text has to differ too, or a palette with a dark background and dark text
		// would pass the background check and be unreadable.
		if read(light, "color.semantic.text") == read(dark, "color.semantic.text") {
			t.Errorf("%s resolves the same text colour in both appearances", def.Slug)
		}
	}
}