test/runtests.jl: Add missing tests for positional masks.

src/PositionalEmbeddings.jl

@@ -179,7 +179,7 @@ julia> mask = create_causal_mask(3)[:,:,1]
  0  0  1  # Third position can attend to first and second
 ```
 """
-function causal_mask(seq_len::Int)
+function create_causal_mask(seq_len::Int)
     return reshape(triu(trues(seq_len, seq_len), 0), seq_len, seq_len, 1)
 end
 

test/runtests.jl

@@ -233,4 +233,32 @@ end
         @test size(output) == (seq_len, head_size, batch_size)
         @test output[1:5, 1:5, 1] ≈ expected rtol=1e-5
     end
+end
+
+@testset "Mask Functions" begin
+    @testset "create_causal_mask" begin
+        # Test a simple 3x3 causal mask
+        result = create_causal_mask(3)
+        expected = reshape([
+            1 1 1
+            0 1 1
+            0 0 1
+        ], 3, 3, 1)
+        @test result == expected
+        @test size(result) == (3, 3, 1)
+    end
+
+    @testset "create_padding_mask" begin
+        # Test with sequences of different lengths
+        lengths = [2, 3, 1]
+        max_len = 4
+        result = create_padding_mask(lengths, max_len)
+        expected = reshape(permutedims([
+            0 0 1 1
+            0 0 0 1
+            0 1 1 1]
+            ,(2,1)),(1,4,3))
+        @test result == expected
+        @test size(result) == (1, 4, 3)
+    end
 end