What is the test for obtaining consent to search a drug dealer's home?

In Vale v. Louisiana, Supra, 399 U.S. 30, 90 S.Ct. 1969, 26 L.Ed.2d 409, the police officers, possessing warrants for appellant's arrest, were watching the house where he resided. They observed what they suspected was an exchange of narcotics between a known addict and appellant outside the house, after appellant had gone into the house and brought something out to the addict. They arrested appellant at the front steps and announced that they would search the house. No consent was given by appellant.