add tests as documentation

langutil_test.go

@@ -0,0 +1,58 @@
+package span
+
+import "testing"
+
+func TestDetectLang3(t *testing.T) {
+	var cases = []struct {
+		in  string
+		out string
+		err error
+	}{
+		// Hits.
+		{"", "", nil},
+		{"indivisible, with liberty and justice for all", "eng", nil},
+		{"in Hoffnung den Grund und die rechte Tieffe darinnen zu finden", "deu", nil},
+		{"uomo di cultura e appassionato di astronomia", "ita", nil},
+		{"С Востока свет, с Востока силы!", "rus", nil},
+		{"Tiam drako estis simbolo de la supernatura", "epo", nil},
+		{"Le long du vieux faubourg, où pendent aux masures", "fra", nil},
+		{"Hello World: Eine Einführung", "deu", nil},
+		{"Reflections on Gestalt therapy", "eng", nil},
+		// Misses.
+		{"Hello World", "nld", nil},
+		{"Samedi soir", "nno", nil},
+		{"Samedi soir, je viendrai dîner avec mon amie.", "nno", nil},
+	}
+	for _, c := range cases {
+		result, err := DetectLang3(c.in)
+		if result != c.out {
+			t.Fatalf("got %v, want %v", result, c.out)
+		}
+		if err != c.err {
+			t.Fatalf("got %v, want %v", err, c.err)
+		}
+	}
+}
+
+func TestLanguageIdentifier(t *testing.T) {
+	var cases = []struct {
+		in  string
+		out string
+	}{
+		// Hits.
+		{"German", "deu"},
+		{"de", "deu"},
+		{"ger", "deu"},
+		{"serbo-croatian", "hbs"},
+		{"Albanian", "sqi"},
+		// Misses.
+		{"Deutsch", ""},
+		{"de_DE", ""},
+	}
+	for _, c := range cases {
+		result := LanguageIdentifier(c.in)
+		if result != c.out {
+			t.Fatalf("got %v, want %v", result, c.out)
+		}
+	}
+}