Add treasure hunt script

src/tdd_workshop/cli.py

@@ -1,9 +1,10 @@
 import click
-from tdd_workshop.io import read_coordinates  # type: ignore
+from tdd_workshop.io import read_coordinates, treasure_hunt  # type: ignore
 
 
 @click.command()
 @click.argument("file_name", type=click.Path(exists=True))
 def main(file_name: str) -> None:
     coordinates = read_coordinates(file_name)
-    print(f"Read file: {file_name}, coordinates: {coordinates}")
+    treasure_location = treasure_hunt(coordinates)
+    print(f"Found the treasure at: {treasure_location}")

src/tdd_workshop/io.py

@@ -6,7 +6,7 @@
     from typing import Union, List, Tuple
 
 
-def read_coordinates(file_name: Union[str, Path]) -> List[Tuple[str, str]]:
+def read_coordinates(file_name: Union[str, Path]) -> List[Tuple[float, float]]:
     """
     Will read a file of comma separated strings and turn it
     into a list
@@ -15,5 +15,16 @@ def read_coordinates(file_name: Union[str, Path]) -> List[Tuple[str, str]]:
     with open(file_name, "r", encoding="utf-8") as input_file:
         for line in input_file:
             x, y = line.strip().split(",")
-            coordinates.append((x, y))
+            coordinates.append((float(x), float(y)))
     return coordinates
+
+
+def calculate_slope(x1, x2, y1, y2):
+    return (y2 - y1) / (x2 - x1)
+
+
+def treasure_hunt(input_coordinates):
+    for i, (x2, y2) in enumerate(input_coordinates[1:]):
+        x1, y1 = input_coordinates[i]
+        if calculate_slope(x1, x2, y1, y2) > 1:
+            return x2, y2

tests/unit/test_cli.py

@@ -12,16 +12,13 @@ def test_that_cli_fails_when_file_is_missing():
 
 def test_that_cli_prints_coordinates(monkeypatch, tmp_path):
     monkeypatch.chdir(tmp_path)
-    expected_coordinates_list = [
+    coordinates_list = [
         ("2.0", "1.9"),
         ("2.5", "1.5"),
         ("3.3", "7.3"),
     ]
     with open("test_input", "w", encoding="utf-8") as fout:
-        fout.write("\n".join(",".join(coords) for coords in expected_coordinates_list))
+        fout.write("\n".join(",".join(coords) for coords in coordinates_list))
     runner = CliRunner()
     result = runner.invoke(main, ["test_input"])
-    assert result.exit_code == 0
-    assert (
-        "coordinates: [('2.0', '1.9'), ('2.5', '1.5'), ('3.3', '7.3')]" in result.output
-    )
+    assert "Found the treasure at: (3.3, 7.3)" in result.output

tests/unit/test_read_coordinates.py

@@ -1,4 +1,6 @@
-from tdd_workshop.io import read_coordinates
+import pytest
+
+from tdd_workshop.io import read_coordinates, calculate_slope, treasure_hunt
 
 
 def test_that_we_can_split_file_into_coordinates(test_data_path):
@@ -9,12 +11,30 @@ def test_that_we_can_split_file_into_coordinates(test_data_path):
     the file located on disk.
     """
     expected_coordinates_list = [
-        ("1", "1"),
-        ("2.0", "1.8"),
-        ("2.5", "2.1"),
-        ("3", "2"),
-        ("4.3", "7.2"),
-        ("5.3", "6.2"),
+        (1, 1),
+        (2.0, 1.8),
+        (2.5, 2.1),
+        (3, 2),
+        (4.3, 7.2),
+        (5.3, 6.2),
     ]
 
     assert read_coordinates(test_data_path / "test_input") == expected_coordinates_list
+
+
+@pytest.mark.parametrize(
+    "input_vals, expected_result", [[[1, 2, 1, 2], 1], [[1, 2, 1, 4], 3]]
+)
+def test_slope_calculator(input_vals, expected_result):
+    assert calculate_slope(*input_vals) == expected_result
+
+
+def test_slope_calculator_without_parameterize():
+    assert calculate_slope(*[1, 2, 1, 2]) == 1
+    assert calculate_slope(*[1, 2, 1, 4]) == 3
+
+
+
+def test_that_slopes_are_calculated_correctly():
+    input_list = [(1, 1), (2.0, 1.8), (2.5, 2.1), (3, 2), (4.3, 7.2), (5.3, 6.2)]
+    assert treasure_hunt(input_list) == (4.3, 7.2)