BACKEND: Unit Test for Relational Algebra Backend

[JMAR059]

Unit test are needed for different components of the relational algebra backend. The different files and recommended test are:

• booleanParsing.py: Test if parser is building correct boolean tree structure even with nested parenthesis cases and compound statements. Add cases of human error that should throw a syntax error for the parser.
• booleanNodes.py: Test evaluate function extensively with different combinations of data types and boolean tree structures.
• relationParsing.py: Test if parser is building correct relational tree structure for each operation even with nested parenthesis. Add cases of human error that should thorw a syntax error for the parser.
• relationNodes.py: Test resolve function extensively with different combinations of datasets and relation tree structures. Test should be dependent on booleanNode.py tests passing, and should also be indicative of dataframeOperations.py being logically correct.

Importing a python module to check code coverage would be ideal. Unit test can be structures similar to dbs_chase_test.py, made for each seperate file. All test should eventually go under a test folder outside of src/.

Good place to start thinking about test is in the main sections of each of these files, as these were used as 'scratch' for improvised test cases.

In future occasions, any reported bug from a missed edge case in one of these modules MUST have a new test case created for it.