console/frontend: better error formatting

common/helpers/strings_test.go

@@ -0,0 +1,22 @@
+package helpers
+
+import "testing"
+
+func TestCapitalize(t *testing.T) {
+	cases := []struct {
+		In  string
+		Out string
+	}{
+		{"", ""},
+		{"Hello", "Hello"},
+		{"bye", "Bye"},
+		{" nothing", " nothing"},
+		{"école", "École"},
+	}
+	for _, tc := range cases {
+		got := Capitalize(tc.In)
+		if diff := Diff(got, tc.Out); diff != "" {
+			t.Errorf("Capitalize(%q) (-got, +want):\n%s", tc.In, diff)
+		}
+	}
+}