Add comprehensive test suite for all transforms (40 tests)

tests/test_transforms.py

@@ -0,0 +1,156 @@
+"""
+Unit tests for all transforms in itt_solver.transforms.
+
+Usage:
+  python tests/test_transforms.py
+
+40 tests covering: Kronecker, mirror tiles, upscale, downscale, stack,
+rotate, reflect, color ops, gravity, crop, transpose, shifted tile,
+fill enclosed.
+"""
+import numpy as np
+from itt_solver import transforms as tr
+
+INP = np.array([[0,7,7],[7,7,7],[0,7,7]], dtype=float)
+
+tests_passed = 0
+tests_failed = 0
+
+def check(name, condition):
+    global tests_passed, tests_failed
+    if condition:
+        print(f"  ✅ {name}")
+        tests_passed += 1
+    else:
+        print(f"  ❌ {name}")
+        tests_failed += 1
+
+print("=== Kronecker Self-Similar ===")
+T = tr.KroneckerSelfSimilar()
+out = T.apply(INP)
+check("Output shape is 9x9", out.shape == (9, 9))
+check("σ=0 vs known target", np.array_equal(out, np.kron((INP!=0).astype(float), INP)))
+
+print("\n=== KroneckerSelfSimilarInv ===")
+T = tr.KroneckerSelfSimilarInv()
+out = T.apply(INP)
+check("Output shape is 9x9", out.shape == (9, 9))
+
+print("\n=== MirrorTileH ===")
+T = tr.MirrorTileH()
+out = T.apply(INP)
+check("Shape is 3x6", out.shape == (3, 6))
+check("Left half is input", np.array_equal(out[:, :3], INP))
+check("Right half is fliplr(input)", np.array_equal(out[:, 3:], np.fliplr(INP)))
+
+print("\n=== MirrorTileV ===")
+T = tr.MirrorTileV()
+out = T.apply(INP)
+check("Shape is 6x3", out.shape == (6, 3))
+check("Top half is input", np.array_equal(out[:3, :], INP))
+check("Bottom half is flipud(input)", np.array_equal(out[3:, :], np.flipud(INP)))
+
+print("\n=== MirrorTile4Way ===")
+T = tr.MirrorTile4Way()
+out = T.apply(INP)
+check("Shape is 6x6", out.shape == (6, 6))
+
+print("\n=== Upscale 2x ===")
+T = tr.Upscale(2)
+out = T.apply(INP)
+check("Shape is 6x6", out.shape == (6, 6))
+check("Top-left 2x2 block is INP[0,0]", np.all(out[:2, :2] == INP[0, 0]))
+
+print("\n=== Upscale 3x ===")
+T = tr.Upscale(3)
+out = T.apply(INP)
+check("Shape is 9x9", out.shape == (9, 9))
+check("Top-left 3x3 block is INP[0,0]", np.all(out[:3, :3] == INP[0, 0]))
+
+print("\n=== Downscale 2x ===")
+T = tr.Downscale(2)
+big = np.kron(INP, np.ones((2, 2)))
+out = T.apply(big)
+check("Downscale of upscaled recovers original", np.array_equal(out, INP))
+
+print("\n=== StackH 3 ===")
+T = tr.StackH(3)
+out = T.apply(INP)
+check("Shape is 3x9", out.shape == (3, 9))
+check("First third is input", np.array_equal(out[:, :3], INP))
+
+print("\n=== StackV 3 ===")
+T = tr.StackV(3)
+out = T.apply(INP)
+check("Shape is 9x3", out.shape == (9, 3))
+check("First third is input", np.array_equal(out[:3, :], INP))
+
+print("\n=== Rotate 90/180/270 ===")
+for k in [1, 2, 3]:
+    T = tr.Rotate(k)
+    out = T.apply(INP)
+    check(f"Rotate_{90*k} matches np.rot90", np.array_equal(out, np.rot90(INP, k)))
+
+print("\n=== Reflect h/v ===")
+T = tr.Reflect('h')
+check("Reflect_h matches flipud", np.array_equal(T.apply(INP), np.flipud(INP)))
+T = tr.Reflect('v')
+check("Reflect_v matches fliplr", np.array_equal(T.apply(INP), np.fliplr(INP)))
+
+print("\n=== RetainColor ===")
+T = tr.RetainColor(7)
+out = T.apply(INP)
+check("Only 7s remain", np.all(out[INP == 7] == 7))
+check("Non-7 positions are 0", np.all(out[INP != 7] == 0))
+
+print("\n=== RemoveColor ===")
+T = tr.RemoveColor(7)
+out = T.apply(INP)
+check("7s are removed", np.all(out[INP == 7] == 0))
+check("0s stay 0", np.all(out[INP == 0] == 0))
+
+print("\n=== InvertColors ===")
+T = tr.InvertColors()
+out = T.apply(INP)
+check("0→7 swap", np.all(out[INP == 0] == 7))
+check("7→0 swap", np.all(out[INP == 7] == 0))
+
+print("\n=== GravityDown ===")
+T = tr.GravityDown()
+col_in = np.array([[0,7,0],[0,0,7],[7,0,0]], dtype=float)
+out = T.apply(col_in)
+check("Col 0: 7 at bottom", out[2, 0] == 7 and out[0, 0] == 0 and out[1, 0] == 0)
+check("Col 1: 7 at bottom", out[2, 1] == 7 and out[0, 1] == 0)
+
+print("\n=== GravityUp ===")
+T = tr.GravityUp()
+out = T.apply(col_in)
+check("Col 0: 7 at top", out[0, 0] == 7 and out[1, 0] == 0 and out[2, 0] == 0)
+
+print("\n=== CropToContent ===")
+T = tr.CropToContent()
+padded = np.array([[0,0,0,0],[0,7,7,0],[0,7,7,0],[0,0,0,0]], dtype=float)
+out = T.apply(padded)
+check("Crops to 2x2", out.shape == (2, 2))
+check("All 7s", np.all(out == 7))
+
+print("\n=== Transpose ===")
+T = tr.Transpose()
+out = T.apply(INP)
+check("Shape is transposed", out.shape == (3, 3))
+check("Values match transpose", np.array_equal(out, INP.T))
+
+print("\n=== ShiftedTile ===")
+T = tr.tile_to_target_shifted(shift=(1, 1), tile_factor=3)
+out = T.apply(INP)
+check("Shape is 9x9", out.shape == (9, 9))
+check("Differs from vanilla tile", not np.array_equal(out, np.tile(INP, (3, 3))))
+
+print("\n=== FillEnclosedHarmonic ===")
+T = tr.FillEnclosedHarmonic()
+enclosed = np.array([[7,7,7],[7,0,7],[7,7,7]], dtype=float)
+out = T.apply(enclosed)
+check("Center hole filled", out[1, 1] == 7)
+
+print(f"\n{'='*50}")
+print(f"Results: {tests_passed} passed, {tests_failed} failed")