1 files changed, 141 insertions, 0 deletions
diff --git a/ocaml/test/year2024/day04/test_part01.ml b/ocaml/test/year2024/day04/test_part01.ml
new file mode 100644
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+++ b/ocaml/test/year2024/day04/test_part01.ml
@@ -0,0 +1,141 @@
+open Year2024.Day04.Part01
+
+let example_input =
+  [ "MMMSXXMASM"
+  ; "MSAMXMSMSA"
+  ; "AMXSXMAAMM"
+  ; "MSAMASMSMX"
+  ; "XMASAMXAMM"
+  ; "XXAMMXXAMA"
+  ; "SMSMSASXSS"
+  ; "SAXAMASAAA"
+  ; "MAMMMXMMMM"
+  ; "MXMXAXMASX" ]
+
+let is_in_bounds_tests =
+  let test_is_in_bounds expected length index _ =
+    let actual = is_in_bounds length index in
+    assert_equal ~printer:string_of_bool expected actual
+  in
+  [ "not in bounds if below 0" >:: test_is_in_bounds false 1 (-1)
+  ; "in bounds if gte 0 and lt length" >:: test_is_in_bounds true 1 0
+  ; "not in bounds if eq length" >:: test_is_in_bounds false 1 1
+  ; "not in bounds if gt length" >:: test_is_in_bounds false 1 2 ]
+
+let calculate_num_of_matches_tests =
+  let test_calculate_num_of_matches expected line row_offset character _ =
+    let actual = calculate_num_of_matches line row_offset character in
+    assert_equal ~printer:string_of_int expected actual
+  in
+  [ "is 0 when no matches present"
+    >:: test_calculate_num_of_matches 0 "SMMX" 1 {index= 3; character= 'X'}
+  ; "is 1 when only one match present - top to bottom"
+    >::
+    (*
+      |.|X|.|
+      |.|M|.|
+      |.|A|.|
+      |.|S|.|
+    *)
+    test_calculate_num_of_matches 1 ".X..M..A..S." 3 {index= 1; character= 'X'}
+  ; "is 1 when only one match present - top to bottom edge"
+    >::
+    (*
+      |X|.|.|
+      |M|.|.|
+      |A|.|.|
+      |S|.|.|
+    *)
+    test_calculate_num_of_matches 1 "X..M..A..S.." 3 {index= 0; character= 'X'}
+  ; "is 1 when only one match present - bottom to top"
+    >::
+    (*
+      |.|S|.|
+      |.|A|.|
+      |.|M|.|
+      |.|X|.|
+    *)
+    test_calculate_num_of_matches 1 ".S..A..M..X." 3 {index= 10; character= 'X'}
+  ; "is 1 when only one match present - left to right"
+    >::
+    (*
+      |X|M|A|S|
+    *)
+    test_calculate_num_of_matches 1 "XMAS" 4 {index= 0; character= 'X'}
+  ; "is 1 when only one match present - right to left"
+    >::
+    (*
+      |S|A|M|X|
+    *)
+    test_calculate_num_of_matches 1 "SAMX" 4 {index= 3; character= 'X'}
+  ; "is 1 when only one match present - bottom right to top left"
+    >::
+    (*
+      |S|.|.|.|
+      |.|A|.|.|
+      |.|.|M|.|
+      |.|.|.|X|
+    *)
+    test_calculate_num_of_matches 1 "S....A....M....X" 4
+      {index= 15; character= 'X'}
+  ; "is 1 when only one match present - top left to bottom right"
+    >::
+    (*
+      |X|.|.|.|
+      |.|M|.|.|
+      |.|.|A|.|
+      |.|.|.|S|
+    *)
+    test_calculate_num_of_matches 1 "X....M....A....S" 4
+      {index= 0; character= 'X'}
+  ; "is 1 when only one match present - bottom left to top right"
+    >::
+    (*
+      |.|.|.|S|
+      |.|.|A|.|
+      |.|M|.|.|
+      |X|.|.|.|
+    *)
+    test_calculate_num_of_matches 1 "...S..A..M..X..." 4
+      {index= 12; character= 'X'}
+  ; "is 1 when only one match present - top right to bottom left"
+    >::
+    (*
+      |.|.|.|X|
+      |.|.|M|.|
+      |.|A|.|.|
+      |S|.|.|.|
+    *)
+    test_calculate_num_of_matches 1 "...X..M..A..S..." 4
+      {index= 3; character= 'X'}
+  ; "is 8 when matches present in all possible directions"
+    >::
+    (*
+            |S|.|.|S|.|.|S|
+            |.|A|.|A|.|A|.|
+            |.|.|M|M|M|.|.|
+            |S|A|M|X|M|A|S|
+            |.|.|M|M|M|.|.|
+            |.|A|.|A|.|A|.|
+            |S|.|.|S|.|.|S|
+    *)
+    test_calculate_num_of_matches 8
+      "S..S..S.A.A.A...MMM..SAMXMAS..MMM...A.A.A.S..S..S" 7
+      {index= 24; character= 'X'} ]
+
+let solve_tests =
+  let test_solve have want () =
+    let actual = solve have in
+    Alcotest.(check int) "incorrect solution" want actual
+  in
+  [ ( "test solution"
+    , [ Alcotest.test_case "example is solved correctly" `Quick
+        @@ test_solve example_input 18
+      ; Alcotest.test_case "minimal example is solved correctly" `Quick
+        @@ test_solve ["..X..."; ".SAMX."; ".A..A."; "XMAS.S"; ".X...."] 4 ] )
+  ]
+
+let () =
+  let open Alcotest in
+  run "test suite for day 4 part 1" is_in_bounds_tests
+  @ calculate_num_of_matches_tests @ solve_tests