From 068d3919c734c939f19c196eaef79fe286659f75 Mon Sep 17 00:00:00 2001 From: Mark Pilgrim Date: Thu, 16 Jul 2009 23:19:45 -0400 Subject: [PATCH] fixed FIXMEs --- unit-testing.html | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/unit-testing.html b/unit-testing.html index c8338a6..f9aba84 100755 --- a/unit-testing.html +++ b/unit-testing.html @@ -141,7 +141,7 @@ function to_roman(n): '''convert integer to Roman numeral''' pass ①
    -
  1. At this stage, you want to define the API of the to_roman() function, but you don’t want to code it yet. (Your test needs to fail first.) To stub it out, use the Python reserved word pass [FIXME ref], which does precisely nothing. +
  2. At this stage, you want to define the API of the to_roman() function, but you don’t want to code it yet. (Your test needs to fail first.) To stub it out, use the Python reserved word pass, which does precisely nothing.

Execute romantest1.py on the command line to run the test. If you call it with the -v command-line option, it will give more verbose output so you can see exactly what’s going on as each test case runs. With any luck, your output should look like this: 

@@ -254,7 +254,7 @@ OK
  • Like the previous test case, the test itself is a method of the class, with a name starting with test.
  • The unittest.TestCase class provides the assertRaises method, which takes the following arguments: the exception you’re expecting, the function you’re testing, and the arguments you’re passing to that function. (If the function you’re testing takes more than one argument, pass them all to assertRaises, in order, and it will pass them right along to the function you’re testing.) -

    Pay close attention to this last line of code. Instead of calling to_roman() directly and manually checking that it raises a particular exception (by wrapping it in a try...except block [FIXME xref]), the assertRaises method has encapsulated all of that for us. All you do is tell it what exception you’re expecting (roman2.OutOfRangeError), the function (to_roman()), and the function’s arguments (4000). The assertRaises method takes care of calling to_roman() and checking that it raises roman2.OutOfRangeError. +

    Pay close attention to this last line of code. Instead of calling to_roman() directly and manually checking that it raises a particular exception (by wrapping it in a try...except block), the assertRaises method has encapsulated all of that for us. All you do is tell it what exception you’re expecting (roman2.OutOfRangeError), the function (to_roman()), and the function’s arguments (4000). The assertRaises method takes care of calling to_roman() and checking that it raises roman2.OutOfRangeError.

    Also note that you’re passing the to_roman() function itself as an argument; you’re not calling it, and you’re not passing the name of it as a string. Have I mentioned recently how handy it is that everything in Python is an object?

    So what happens when you run the test suite with this new test?