exactness is a software package aimed to automate Elementary testing
after updating elm code.
The testing process is composed of running widget test,
cycling through API functions, and screenshot are taken on each stage of test.
(on user request with F2 key).

Next, these screenshots are compared with screenshots of widget test
done before the code update.
When exactness detects difference in screenshot comparison,
it means widget layout was changed.
Unexpected layout changes may reveal that something is broken
in the new implementation.

Testing with exactness composed of the following stages:
1. Test Recording.
   Done once and exactness user most likely does not need to do this.
   A set of pre-recorded tests already resides under 'data/recording' folder.

   To record a test just issue the command:
   exactness -r [-b BaseDir] [TestName1] [TestName2 ...]

   Example:
   exactness -r test_hover

   The record file will be produced in the current-working-directory as:
   test_hover.rec

   To save your recordings in any other directory,
   pass the directory-name as base-dir:
   exactness -r -b /home/username/my_recordings test_hover

   In case you tried to run exactness with specific TestName
   getting "No test matching" Error.
   This means you misspelled the test name.
   You may review test names as it appears in tsuite.c source file.

   NOTE: omitting the test name causes recording all tests one after another.
   Do this if you only mean it.
   This rule applies to ALL proceeding stages as well.

   As widget test run you may press F2 at any point to set a screenshot.
   (screenshot produced in 'play' stage, set timing of screenshot here)
   However, don't do this while animation is ongoing
   or you get inconsistent PNG output each time test played.

   NOTE: You may change screenshot key from F2 to any other key
         with TSUITE_SHOT_KEY env var.

2. Test Initiation.
   The final stage of testing process is based on PNG image comparison
   of original screenshots with current screenshots produced after code change.

   To start you need to produce original screenshot set before code change.
   To do that just issue the command:
   exactness -i [-b BaseDir] [TestName1] [TestName2 ...]

   This command will play the test (TestName.rec file) and place PNG files
   under 'orig' folders created in current-working-directory.
   You need to do this just once.
   Again, omitting the TestName will play and produce PNG files for all tests.

   exactness -i test_hover
   (locate "test_hover.rec" in cwd)

   This will produce PNG files such orig/test_hover_1.png

   By default exactness looks for ".rec" files in current-working-directory
   Use -b DirName to ask exactness to locate the ".rec" files
   in a specific location.

   Example:
   exactness -i -b ${prefix}/share/exactness/recordings test_hover
   (locate "test_hover.rec" in "${prefix}/share/exactness/recordings")
   

3. Test playing, producing current state PNG files and comparison files (4).
   After doing Test Initiation (2) and updating elementary code,
   you may run tests for current state of elm:

   exactness -p [-b BaseDir] [-d DestDir] TestName1 [TestName2 ...]
   Omitting DestDir param will cause exactness place all PNG files
   under (default) folder named 'current'.
   Note that comparing PNG files (4) is also done upon completion of play.
   This will produce comp_*.png files in your DestDir.

   You may put record-files at specific folder with -b (base dir) argument:
   Example:
   exactness -p -b ${prefix}/share/exactness/recordings

   Play test_hover, find ".rec" file at "${prefix}/share/exactness/recordings"
   Write resulting PNG files at cwd/current (default) dir
   along with comp_*.png files.
   
4. Comparing PNG files.
   This is the final stage of testing in which we compare output
   before code update and after the update.
   Following 'play' action, matching PNG files from 'orig' and 'current'
   folder are compared.

   When all comparisons done you get final report of (N) files did not match.
   In case difference was found, you may look at comp_*.png files in DestDir.

5. fail_if(expr) macro:
   You may use fail_if(expr); macro to verify variable value on-the-fly.
   For example, if your code contains:

   char *p;
   ...
   fail_if(p == NULL);

   In case (p == NULL), a "fail_TestName.txt" file is crated
   current working directory with a comment specifying the expr/line failed.

   fail_*.txt files are produced only for when expr fails when running.
   When tests completed, the user gets notification message if any tests failed.
   In such case, please review the fail_*.txt files.

6. To view exactness help issue the command:
   exactness --help
   or
   exactness -h