mog project: Code coverage in Python

6.26.2011

Code coverage in Python

Python: コード網羅率の可視化ツール

Python における Code coverage ツールは現時点において以下の2種類である。
インストールコマンドと共に記す。
　・Code coverage (coverage.py)　　=> easy_install coverage
　・trace2html (trace2html.py)　　=> easy_install trace2html

後者の方がより明解なHTMLで表示されるので、こちらを採用する。

・ヘルプ

   1: Usage: trace2html.py [options]   2:     3: Utility to generate HTML test coverage reports for python programs   4:     5: Example usage   6: -------------   7:     8: Use trace2html to directly compute the coverage of a test suite by   9: specifying the module you are interested in::  10:    11:   $ trace2html.py -w my_module --run-command ./my_testrunner.py  12:   $ firefox coverage_dir/index.html  13:    14: Or you can collect coverage data generated with trace.py::  15:    16:   $ /usr/lib/python2.4/trace.py -mc -C coverage_dir -f counts my_testrunner.py  17:    18: Write a report in directory 'other_dir' from data collected in 'counts'::  19:    20:   $ trace2html.py -f counts -o other_dir  21:   $ firefox other_dir/index.html  22:    23:    24:    25: Options:  26:   -h, --help            show this help message and exit  27:   -f COVERAGE_FILES, --coverage-file=COVERAGE_FILES  28:                         Use the content of a trace file  29:   -o REPORT_DIR, --output-dir=REPORT_DIR  30:                         Directory to store the generated HTML report. Defaults  31:                         to 'coverage_dir'  32:   -s CSS, --with-css-stylesheet=CSS  33:                         Use an alternative CSS stylesheet  34:   -t, --self-test       Run the tests for trace2html  35:   -v, --verbose         Set verbose mode on (cumulative)  36:   -r, --run-command     Collect coverage data by running the given python  37:                         script with all trailing arguments  38:   -b BLACKLIST_MODS, --blacklist-module=BLACKLIST_MODS  39:                         Add a module to the black list  40:   -B BLACKLIST_DIRS, --blacklist-dir=BLACKLIST_DIRS  41:                         Add a directory to the black list  42:   -w WHITELIST_MODS, --whitelist-module=WHITELIST_MODS  43:                         Add a module to the white list  44:   -W WHITELIST_DIRS, --whitelist-dir=WHITELIST_DIRS  45:                         Add a directory to the white list

基本的な構文は、
　trace2html.py –w Coverageを計測したいモジュール名 [-w モジュール名] –r ユニットテストモジュールのパス
といった塩梅。

・実行例

   1: > trace2html.py -w shogi.state -w shogi.piece -r .\test_state.py   2: Testing...   3: .....   4: ----------------------------------------------------------------------   5: Ran 5 tests in 5.373s   6:     7: OK   8: report written to: カレントディレクトリ\coverage_dir\index.html