Update README.md

README.md

+# KDTesting 
+
+Python library for testing applications using IO.
+
+# Basics 
+
+The library works using ValueGenerators (not python generators) and Arbitrary classes. 
+
+# Test 
+
+Test is container that holds name, arbitrary and value provided by said arbitrary. The test also contains functions `shrink` and `to_str` (using `to_str` from arbitrary on value). 
+
+# Tester
+
+Tester is abstract class, the most important function `run_test(test: Test[G])` is not defined.
+
+# RefImlTester
+
+Tester that runs tests on your implementation and the reference implementation, then runs your process output tests on the outputs.
+
+## ProcessOutputTest
+
+Type is `Callable[[ProcessOutput, ProcessOutput], bool]`, it takes the outputs (in format provided by the `subprocess.run`) and returns bool.
+
+There are some presets: 
+- `stdout_equality()`: returns test, that only compares the raw stdout
+- `stdout_processed_equality(test_preprocessor, exp_preprocessor)`: returns test that compares processed stdouts. `test_preprocessor` and `exp_preprocessor` are `Callable[[str], str]` that "process" the stdout (you have to define these, there is `str_id` that returns the input unchaged `x -*> x`)
+
+## Example use
+
+```python
+def ignore_numbers(x: str):
+    return re.sub(r'\d+', '', x)
+
+# `program_tst` and `program_exp` are absolute paths pointing to the executables
+# 3 - verbosity (default is 5, too much) 
+tester = RefImplTester(program_tst, program_exp, 3)
+tester.add_output_test(stdout_processed_eqality(ignore_numbers, ignore_numbers))
+
+for i in range(5):
+    # `command_sequence` is a custom arbitrary that returns sequence of 
+    # `\n` delimitered commands
+    tester.add_test(Test(f"all_{i}", command_sequence)) 
+
+# runs the test, returns (reduced test, number of shrinks) tuple 
+reduced_tests = tester.run()
+
+# prints the failed tests, first the name, the number of shrinks, the test, 
+# then saves it as .tst file 
+for test, shrinks in reduced_tests:
+    print(test.name, shrinks)
+    print(test.to_str())
+    tester.save_shrunk(reduced_tests)
+
+# also saves the original tests
+tester.save_tests()
+```
+
+# Arbitraries 
+
+`Arbitrary[T]`
+
+### Get
+`get() -> T`
+
+returns arbitrary value generated by the Arbitrary
+
+
+### Shrink
+`shrink(value: T) -> List[T]`
+
+shrinks any value created by the Arbitrary to simpler value
+
+### To string
+`to_str(value: T) -> str`
+
+converts the value to string 
+
+## The arbitraries currently present are: 
+
+### NumberA(min_value, max_value)
+get returns: number in [min_value, max_value)
+
+shrinks value to: val // 2, val moved towards 0
+
+### ConstantA(constant)
+get returns: constant 
+
+shrinks value to: nothing
+
+### TupleA(arbs)
+get returns: tuple where i-th value uses i-th arbitrary from arbs
+
+shrinks value to: list of different tuples with shrunk values 
+
+### ListA(arb, min_size, max_size)
+get returns: list with length [min_size, max_size)
+
+shrinks value to: shorter lists
+
+### ChoiceA(choices)
+get returns: tuple (index of chosen arb, value generated by that arb), choice is random
+
+shrinks value to: tuples with shrunk values (index of the chosen arb, value shrunk using said arb)
+
+
+
+