feat(fsharp): m01-m06 util, model, rules, random, spawn, game, view with Expecto tests

Co-Authored-By: Claude Opus 5.5 <[email protected]>

fsharp/tests/M01Util.fs

@@ -0,0 +1,34 @@
+module Snake.Tests.M01Util
+
+open Expecto
+open Snake
+open Snake.Model
+
+// The JavaScript m01 also has `pipe` and `compose`; in F# they are built in as `|>` and `>>`, so there is nothing to test.
+
+let private sameParity a b = a % 2 = b % 2
+
+[<Tests>]
+let tests =
+    testList "M01 Util" [
+        testCase "range 0 is empty" (fun () -> Expect.equal (Util.range 0) [] "range 0")
+        testCase "range 3 counts from zero up to n-1" (fun () -> Expect.equal (Util.range 3) [ 0; 1; 2 ] "range 3")
+
+        testCase "dropLast of an empty list is empty" (fun () ->
+            Expect.equal (Util.dropLast ([]: int list)) [] "dropLast []")
+        testCase "dropLast removes only the last element" (fun () ->
+            Expect.equal (Util.dropLast [ 1; 2; 3 ]) [ 1; 2 ] "dropLast [1;2;3]")
+        testCase "dropLast leaves its input untouched" (fun () ->
+            let xs = [ 1; 2; 3 ]
+            Expect.equal (Util.dropLast xs) [ 1; 2 ] "result"
+            Expect.equal xs [ 1; 2; 3 ] "input")
+
+        testCase "contains finds an element using the supplied equality" (fun () ->
+            Expect.isTrue (Util.contains [ 1; 2; 3 ] 5 sameParity) "5 has the parity of 1")
+        testCase "contains is false when no element is equal" (fun () ->
+            Expect.isFalse (Util.contains [ 2; 4 ] 3 sameParity) "no odd element")
+        testCase "contains is false for an empty list" (fun () ->
+            Expect.isFalse (Util.contains [] 1 (=)) "empty list")
+        testCase "contains compares structurally when given a structural equality" (fun () ->
+            Expect.isTrue (Util.contains [ { X = 1; Y = 2 } ] { X = 1; Y = 2 } (=)) "same point")
+    ]