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This program was written with Cleanroom intended functions.
There was a gap of about three months at a point just
before the writing of the processFile() function.
No self-verification or peer verification was done. Defects are counted from the first compilation. Defects are broken down into three categories: see Section 6.1, “Syntax errors”; Section 6.2, “Strong typing errors”; and Section 6.3, “Logic errors”.
Syntax errors caught by Python while scanning modules.
In main(), omitted the colon
at the end of this line:
for archNo in sys.argv[1:]:
These are errors that would have been caught at compile time in a more strongly typed language such as Java.
In processFile(), this line:
result.save ( thumbPath )
did not work, because result
is an Imagex object. The
desired method is on that object's attribute,
result.image:
result.image.save ( thumbPath )
In Imagex.writeNode(), the
original code to build the dictionary of attributes
for the RNC_IMAGE_N node looked
like this:
attrs = { RNC_CAT_NO_A: self.baseName,
RNC_WIDE_A: self.wide,
RNC_HIGH_A: self.high }
However, the DOM expects attribute values to be
strings, and self.wide and
self.high are floats. Some
formatting fixes things right up:
attrs = { RNC_CAT_NO_A: self.baseName,
RNC_WIDE_A: "%.1f" % self.wide,
RNC_HIGH_A: "%.1f" % self.high }
The code above is no longer in the script; the width and height attributes have since been changed to integers.
When writing the archindex.py module,
neglected to write the ArchiveIndex.addArchImage() method.
Ordinary logic errors.
Function processFile()
declared a precondition that pathName cannot be the empty string.
This precondition was added during design when I
realized that the expression baseName[0] would fail with the empty
string. I didn't think this was problem, because
os.listdir() wouldn't
produce an empty file name.
However, what is tested is the base
name, which is the path name without its
directory and extension. Unfortunately, a defect
emerged in testing. The file name in question was
the “hidden file” bird-001/.xvpics. Using os.path.split() on this string yields
the tuple ('bird-001/',
'.xvpics'), and using os.path.splitext() on that produces
('', '.xvpics'), and the
expression baseName[0] fails
with an IndexError.
The fix is to quietly return None whenever the baseName is empty, because hidden files
cannot be bird images.
In writeIndex(), neglected
to prepend INDEX_DIR to the
name of the output file.