The phrase "a clear test of" is correct and usable in written English.
It can be used when discussing an evaluation or assessment that is straightforward and unambiguous in measuring a particular quality or ability.
Example: "The final exam serves as a clear test of the students' understanding of the course material."
Alternatives: "an unequivocal measure of" or "a definitive assessment of".
Such a meeting, he said, would provide a clear test of whether Mr. Arafat had put violence behind him.
The Russians would be likely to embrace such a proposal for commercial and political reasons, and the Iranians would be confronted with a clear test of whether they harbor nuclear weapons ambitions.
It found the "invention" (a way of hedging commodity risks) too abstract to be patentable, but failed to provide a clear test of what constituted an abstract idea for judges in lower courts to apply.
That entanglement is less because of the film's production costs — about $150 million, after the financial incentives of Louisiana, where it was mostly filmed — than because it provides a clear test of Mr. Grey's determination to occasionally serve art and commerce in the same picture.
Six specific access or information issues will be addressed over the next three months, offering a clear test of Iran's willingness to provide greater clarity about its activities, says the BBC's diplomatic correspondent Jonathan Marcus.
Our engagement on human trafficking is a clear test of which rules we value, and the kind of leadership we will express through our trade policy.
In view of the Corsican factor, yielding over SNCM does not necessarily imply that the government will go soft on other fronts.The one-day national strike was a clearer test of the government's will-power.
Measuring profits the good old single bottom line offers a pretty clear test of business success.
And rather than a clear test case, Baltimore is a reminder of how complicated policing issues are and how hard it can be to draw solid conclusions from a month or two of crime and police response.
There could hardly be a clearer test case of what, if anything, 12 years of bruising encounters with public-sector reform have taught it.
Whether or not Bannon remains in the White House, one clear test of whether Trumpism means anything more than the scapegoating of non-whites is whether the Republican Congress's ambitious fall legislative agenda takes a more economically populist turn.
