attest
at + test (测试) = 写软件的时候做测试就是为了证明能不能用
To attest something or attest to something means to say, show, or prove that it is true.
Her outstanding abilities were attested by her rapid promotion. 她杰出的才干已经由她获得迅速提升而得到证明。
test做词根的单词还有testify，testament。
testify
证明，证实；If one testifies to another, it supports the belief that the second thing is true.
Recent excavations testify to the presence of cultivated inhabitants on the hill during the Arthurian period. 最近几次发掘证实了亚瑟王时期这座山上有农耕人口居住过。
(法庭上)作证，证明 When someone testifies in a court of law, they give a statement of what they saw someone do or what they know of a situation, after having promised to tell the truth.
Several eyewitnesses testified that they saw the officers hit Miller in the face… 几位目击证人证明他们看见那几个警官打了米勒的脸。
testament
（名词）证据，证明
If one thing is a testament to another, it shows that the other thing exists or is true.
The fact that these scandals are now public is testament to the relative openness of America’s government. 这些丑闻如今公之于众的事实说明了美国政府的相对透明。
最新遗嘱;[尤指]临终遗嘱,临终遗言
Someone’s last will and testament is the most recent will that they have made, especially the last will that they make before they die.