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5,123 bytes added ,  06:15, 18 March 2018
→‎Shared functions: "between" is only for two
Having a thorough [https://en.wikipedia.org/wiki/Test_suite test suite] is something very important which is usually overlooked. It is an incredible help in preventing regression bugs and quickly assess the status of old code. For example, many packages in Octave Forge become deprecated after losing their maintainer simply because they have no test suite. GNU Octave has multiple tools that help in creating a comprehensive test suite, accessible to both developers and end-users, as detailed on the [http://www.gnu.org/software/octave/doc/interpreter/Test-Functions.html Octave manual]. Basically, test blocks are {{codeline|%!test}} comment blocks, typically at the end of a source file, which are ignored by the Octave interpreter and only read by the {{manual|test}} function. == Running tests = Tests =Writing To run all the tests of a specific function, simply use the {{manual|test}} command at the Octave prompt. For example, to run the tests of the Octave function {{manual|mean}} type:  >> test mean PASSES 17 out of 17 tests These tests for are written in the Octave language [http://hg.savannah.gnu.org/hgweb/octave/file/6443693a176f/scripts/statistics/base/mean.m#l130 at the bottom of <code>mean.m</code>] which defines the {{manual|mean}} function . It is an important thing that is usually overlookedthese tests are also available for the end users so they can test the status of their installation. The whole Octave test suite can be run with:  >> __run_test_suite__ Integrated test scripts: [...] Summary: PASS 11556 FAIL 3 XFAIL 6 SKIPPED 38 See the file test/fntests.log for additional details. It helps  To run tests in a specific file, one can simply specify the path instead of a lot in preventing regressionfunction name:  test /full/path/to/file.m
== Writing tests ==
=== in .m files ===
=== in .cc files ===
===declaring functions inside a test block===
Tests appear as <code>%!</code> blocks at the bottom of the source file, together with <code>%!demo</code> blocks. A typical m function file, will have the following structure: <syntaxhighlight lang="Octave">## Copyright#### A block with the copyright notice ## -*- texinfo -*-#### A block with the help text function experience[x, y, z] = foo (bar) ## some amazing codeendfunction %!assert (foo (1))%!assert (foo (1:10))%!assert (foo ("on"), "off")%!error <must be positive integer> foo (-1)%!error <must be positive integer> foo (1.5) %!demo%! ## see how cool foo() is: %!foo([1:100])</syntaxhighlight> Tests can be added to oct functions in the C++ sources just as easily, see[http://hg.savannah.gnu.org/hgweb/octave/file/f5ad7470d957/libinterp/corefcn/find.cc#l566 find.cc]for example. The syntax is exactly the same, but done within C comment blocks.During installation, these lines are automatically extracted from the sourcesand special testscripts are generated. A typical C++ source file has thefollowing structure: <syntaxhighlight lang="c++">// Copyright//// A block with the copyright notice DEFUN_DLD (foo, args, ,"-*- texinfo -*-\n\A block with the help text"){ // some amazing code} /*%! experience_design_matassert (foo (1)) %! experience_obs_eqsassert (foo (1:10)) %! assert (experience_design_mat foo ("on"), "off")%!error <must be positive integer> foo (-1)%!error <must be positive integer> foo (1.5)*/</syntaxhighlight> === Assert =={{codeline|%!assert}} lines are the simplest tests to write and also the mostcommon: <syntaxhighlight lang= pi"Octave">%!assert (foo (bar)) # test fails if "foo (bar)" returns false%!assert (foo (bar), qux) # test fails if "foo (bar);" is different from "qux"</syntaxhighlight> These are actually a shorthand version of{{codeline|%!test assert (foo (bar))}}, and {{codeline|assert}} is simplyan Octave function that throws an error when two arguments fail to compare. === Test === While single {{codeline|%!assert}} lines are the most common used tests, {{codeline|%!test}} blocks offer more features and flexibility. The code within {{codeline|%!test}} blocks is simply processed through the Octave interpreter. If the code generates an error, the test is said to fail. Often {{codeline|%! test}} blocks end with a call to {{codeline|assert (experience_obs_eqs }}: <syntaxhighlight lang="Octave">%!test%! a = [0 1 0 0 3 0 0 5 0 2 1];%! b =[2 5 8 10 11];%! for i = exp1:5%! assert (find (a, i), b(1:i));%! endfor</syntaxhighlight> ==== Test for no failure ==== In a few cases, there is the situation where a function returns nothing,and the only thing to test is that it causes no error. This can be testedsimply with: <syntaxhighlight lang="Octave">%!test foo (bar)</syntaxhighlight> === Error / Warning === It is also important to test that a function performs its checks correctlyand throws errors (or warnings) when it receives garbage. This can be done with{{codeline|error}} (or {{codeline|warning}}) blocks: <syntaxhighlight lang="Octave">%! endfunction error foo () # test that causes any error% this is !error <BAR must be a trickpositive integer> foo (-1.5) # test that throws specific error message%!error id=Octave:invalid-fun-call foo () # test that throws specific error id %! warning foo () # test that causes any warning% now we can declare !warning <negative values might give inaccurate results> foo (-1.5) # test that triggers a specific warning message%!warning id=BAR:possibly-inaccurate-result foo (-1.5) # test that triggers a specific warning id</syntaxhighlight> === Shared functions === It is often useful to be used by share a function among multiple tests. Sometimesthese are only small helper functions, but more often these are just simplerlow performance implementations of the test abovefunction being tested. These are created in {{codeline|%!function}} blocks: <syntaxhighlight lang="Octave"> %! function a x = experience_design_mat slow_foo (bar) %! ## a = pi;simple implementation of foo, definitely correct, but%! ## unfortunately too slow for anything other than tests.%! endfunction %!assert (foo (bar), slow_foo (bar)) %!test %! function b for i = experience_obs_eqs-100:100 %! b bar = expqux (1i); %! % endfunction: don't add it here. Let test assert (foo (bar), slow_foo (bar) do it.)%! endfor</syntaxhighlight>
== running tests ==[[Category:Testing]]=== from m files ====== from .cc files ===You can run tests in .cc files by doing something like test /full/path/to/file.cc[[Category:Development]]
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