Add configuration

theme_test.go

@@ -0,0 +1,20 @@
+package main
+
+import "testing"
+
+func TestApplyThemeChangesAllRenderingThemes(t *testing.T) {
+	defer func() {
+		if err := applyTheme("dark"); err != nil {
+			t.Fatal(err)
+		}
+	}()
+	if err := applyTheme("light"); err != nil {
+		t.Fatal(err)
+	}
+	if markdownStyleName != "light" || codeHighlightTheme != "github" {
+		t.Fatalf("light theme did not propagate: markdown=%q code=%q", markdownStyleName, codeHighlightTheme)
+	}
+	if err := applyTheme("unknown"); err == nil {
+		t.Fatal("unknown theme was accepted")
+	}
+}