(trial judge had discretion to require proof of liability); Metric Investment, Inc. v. Patterson, 98 N.J.Super. 130, 133, 236 A.2d 187 (Law Div.1967) (the entry of default does, not necessarily obviate the obligation of plaintiff to furnish proof on the issue of liability), affd 101 N.J.Super. 301, 244 A.2d 311 (App.Div.1968). Cf. also Prickett v. Allard, 126 N.J.Super. 438, 440, 315 A.2d 51 (App.Div.) (denying default judgment to foreclose a tax sale certificate on grounds of failure to state a claim when plaintiffs complaint on its face demonstrated that the action was barred by the statute of limitations), aff'd o.b., 66 N.J. 6, 326 A.2d 688 (1974); In re Estate of Sharp, 151 N.J.Super. 579, 582, 377 A.2d 730 (Ch.Div.1977), mod. 163 N.J.Super. 148, 394 A.2d 381 (App.Div. 1978) (<HOLDING>). We do not rule at this time that Newman’s
holding that the court may sua sponte refuse to enter judgment for plaintiff if the complaint on its face fails to state a cause of action as to which relief can be granted holding that a court may rely on documents incorporated into the complaint by reference and matters of which a court may take judicial notice in deciding whether a complaint fails to state a claim upon which relief may be granted recognizing that a district court may sua sponte dismiss a complaint for failure to serve after notice to the plaintiff holding that amendment is futile if the proposed amended complaint does not state a claim upon which relief can be granted holding that the court can raise res judicata sua sponte even on appeal