Testament of a Generation: The Journalism of Vera Brittain and Winifred Holtby, edited by Paul Berry and Alan Bishop. London: Virago Press, imported by Salem House. 390 pp. Illustrated. $9.95. Paperback. The friendship Vera Brittain commemorated in her book ``Testament of Friendship'' (1940) began with mutual dislike in 1919 at Oxford and ended only with Winifred Holtby's early death in 1935. In addition to the sustaining power it had in their personal lives, this warm and supportive relationship had a wonderfully beneficial effect on their separate, but equally impressive, journalistic careers. For, although Brittain is best remembered for her autobiographical ``Testaments,'' and Holtby for her novels (most notably, ``South Riding''), the two women were outstanding journalists, who read and encouraged each other's writing. This well-edited collection reflects their shared interests in feminism, socialism, and pacificism, as well as Holtby's concern for the plight of blacks in South Africa (which she first visited in 1926) and Brittain's concern about the evils of saturation bombing in World War II. The writings of both women show humor, sanity, grace under pressure -- of deadlines and other constraints -- and maintain a standard of accuracy and intelligence. It is amazing how so many of these pieces read as freshly today as when they were written and how many of the issues we ponder were also deliberated by Brittain or Holtby in essays that can still shed light upon them.