Syntactic Sugar for TestReports

Question

Seems to me that VerificationTests are a bit verbose:

TestReport[{VerificationTest[StringFreeQ["apple", "lp"], True], 
  VerificationTest[StringFreeQ["apple", "a" ~~ __ ~~ "e"], False], 
  VerificationTest[StringFreeQ["apple", "ap"], False], 
  VerificationTest[StringFreeQ["apple", "x"], True], 
  VerificationTest[StringFreeQ["", "asd"], True]}]

This was the first obvious thing that I tried:

args := {{"apple", "lp"}, {"apple", "a" ~~ __ ~~ "e"}, {"apple", "ap"}, {"apple", "x"}, {"", "asd"}};
results := {True, False, (Pause[2]; False), True, True};

tr = TestReport[
  VerificationTest @@@ Thread[{StringFreeQ @@@ args, results}], 
  TimeConstraint -> Quantity[1, "Seconds"]]

But this solution has many problems:

Timing specs and information aren't enforced and preserved
Evaluations may leak

What are some elegant ways to cut down the verbosity here without messing with evaluation mechanics of the arguments to VerificationTest?

score 11 · Accepted Answer · answered May 08 '16 at 02:33

You can make it look somewhat more pleasant by using simple expression parsers. For example, define an auxiliary head Tests, as follows:

ClearAll[transformTest];
SetAttributes[transformTest, {HoldAll, Listable}];
transformTest[lhs_ -> rhs_] := Hold[VerificationTest[lhs, rhs]];
transformTest[Tests[tests___]] := Thread[transformTest[{tests}], Hold];


ClearAll[Tests];
SetAttributes[Tests, HoldAll];
Tests /: TestReport[t_Tests, args___] :=
  Replace[
    transformTest[t],
    Hold[tests___] :> TestReport[tests, args]
  ];

And now you can use the following syntax:

TestReport @ Tests[
  StringFreeQ["apple", "lp"] -> True, 
  StringFreeQ["apple", "a" ~~ __ ~~ "e"] -> False,
  StringFreeQ["apple", "ap"] -> False, 
  StringFreeQ["apple", "x"] -> True,
  StringFreeQ["", "asd"] -> True
]

which looks a little nicer to me.

score 3 · Answer 2 · edited Apr 13 '17 at 12:55

You can make your own code work simply enough by controlling evaluating with e.g. Inactive

Inactive[TestReport][
  Inactive[VerificationTest] @@@ 
   Thread[{Inactive[StringFreeQ] @@@ args, results}]] // Activate

or Block:

Block[{StringFreeQ, VerificationTest, TestReport},
  TestReport[VerificationTest @@@ Thread[{StringFreeQ @@@ args, results}]]
]

If writing this myself I would probably use my own heldCases and this:

heldCases[
  Thread @ {args, results},
  {{a_, b_}, r_} :>
    VerificationTest[StringFreeQ[a, b], r]
] /. _[x__] :> TestReport[{x}]

I prefer Leonid's more general approach however.

Syntactic Sugar for TestReports

2 Answers2