Add some tests

test/Matrix-test.jl

@@ -1,35 +1,70 @@
 @testset "Matrix.is_lower_triangular" begin
-    A = [ 1 0 0 ; 0 0 1 ; 1 0 1 ]
+    A = [1 0 0; 0 0 1; 1 0 1]
     @test !is_lower_triangular(A)
     @test !is_lower_triangular(matrix(ZZ, A))
 
-    A = [ 1 0 0 ; 0 0 1 ; 0 0 1 ]
+    A = [1 0 0; 0 0 1; 0 0 1]
     @test !is_lower_triangular(A)
     @test !is_lower_triangular(matrix(ZZ, A))
 
-    A = [ 1 0 0 ; 0 0 1 ]
+    A = [1 0 0; 0 0 1]
     @test !is_lower_triangular(A)
     @test !is_lower_triangular(matrix(ZZ, A))
 
-    A = [ 1 0 0 ; 0 1 0 ]
+    A = [1 0 0; 0 1 0]
     @test is_lower_triangular(A)
     @test is_lower_triangular(matrix(ZZ, A))
 end
 
 @testset "Matrix.is_upper_triangular" begin
-    A = [ 1 0 0 ; 0 0 1 ; 1 0 1 ]
+    A = [1 0 0; 0 0 1; 1 0 1]
     @test !is_upper_triangular(A)
     @test !is_upper_triangular(matrix(ZZ, A))
 
-    A = [ 1 0 0 ; 0 0 1 ; 0 0 1 ]
+    A = [1 0 0; 0 0 1; 0 0 1]
     @test is_upper_triangular(A)
     @test is_upper_triangular(matrix(ZZ, A))
 
-    A = [ 1 0 0 ; 0 0 1 ]
+    A = [1 0 0; 0 0 1]
     @test is_upper_triangular(A)
     @test is_upper_triangular(matrix(ZZ, A))
 
-    A = [ 1 0 0 ; 0 1 0 ]
+    A = [1 0 0; 0 1 0]
     @test is_upper_triangular(A)
     @test is_upper_triangular(matrix(ZZ, A))
 end
+
+@testset "Matrix.concat" begin
+    for R in [ZZ, QQ, polynomial_ring(QQ, [:x, :y])[1]]
+        S = matrix_space(R, 3, 3)
+        T = matrix_space(R, 3, 6)
+        U = matrix_space(R, 6, 3)
+
+        A = S([2 3 5; 1 4 7; 9 6 3])
+        B = S([1 4 7; 9 6 7; 4 3 3])
+        C = matrix(R, 2, 2, [1, 2, 3, 4])
+
+        @test hcat(A, B) == T([2 3 5 1 4 7; 1 4 7 9 6 7; 9 6 3 4 3 3])
+
+        @test vcat(A, B) == U([2 3 5; 1 4 7; 9 6 3; 1 4 7; 9 6 7; 4 3 3])
+
+        @test [A B] == hcat(A, B)
+        @test [A A A] == hcat(A, hcat(A, A))
+        @test_throws ErrorException [A C]
+        @test_throws ErrorException [A A C]
+        @test [A; B] == vcat(A, B)
+        @test [A; B; A] == vcat(A, vcat(B, A))
+        @test_throws ErrorException [A; A; C]
+        @test cat(A, A; dims=(1, 2)) == block_diagonal_matrix([A, A])
+        @test cat(A, A; dims=1) == hcat(A, A)
+        @test cat(A, A; dims=2) == vcat(A, A)
+        @test_throws ErrorException cat(A, A; dims=3)
+    end
+end
+
+@testset "Matrix.scalar_matrix" begin
+    S = scalar_matrix(3, QQ(2 // 3))
+    @test S == matrix(QQ, [2//3 0 0; 0 2//3 0; 0 0 2//3])
+    T = scalar_matrix(QQ, 3, 42)
+    @test T == matrix(QQ, [42 0 0; 0 42 0; 0 0 42])
+end