Demonstrate any support for Unit testing built into the language implementation.

See https://en.wikipedia.org/wiki/Unit_testing for more information.

Clearly state whether this support is internal, or external to the interpreter or compiler used.

Jsish

Jsish supports an internal -u command line option to run unit tests, as part of the base implementation. These tests can include trial inputs and expected outputs in special comment blocks within a source file. Other command line options determine the level of verbosity and logging used when running tests. Being inside comment sections, unit tests do not affect the normal operation of a script (besides the negligible time taken for the interpreter to read in and skip over the comment sections). When in -u test-mode, source lines starting and ending with semi-colons ; are echoed using a special output format that also evaluates the enclosed expression and captures the result.

<lang javascript>/* A+B in Jsish */ var line = console.input(); var nums = line.match(/^\s*([+-]?[0-9]+)\s+([+-]?[0-9]+)\s*/); if (nums) {

   var A = Number(nums[1]);
   var B = Number(nums[2]);
   if (A <= 1000 && A >= -1000 && B <= 1000 && B >= -1000) {
       printf("%d\n", A + B);
   } else {
       puts("error: A and B both need to be in range -1000 thru 1000 inclusive");
   }

} else {

   puts("error: A+B requires two numbers separated by space");

}

/*

!INPUTSTART!

a b 1234 123 -1000 +1000 123 -234

!INPUTEND!

/

/*

!EXPECTSTART!

error: A+B requires two numbers separated by space error: A and B both need to be in range -1000 thru 1000 inclusive 0 -111

!EXEPECTEND!

/</lang>

Output:

prompt$ jsish -u A+B.jsi
[PASS] A+B.jsi

prompt$ jsish A+B.jsi
123 -234
-111