Add test, fix bug for chol and test for tridiag (#24411)

base/linalg/cholesky.jl

@@ -406,7 +406,7 @@ function show(io::IO, C::Cholesky{<:Any,<:AbstractMatrix})
         println(io, "$(typeof(C)) with factor:")
         show(io, C[:UL])
     else
-        print("Failed factorization of type $(typeof(C))")
+        print(io, "Failed factorization of type $(typeof(C))")
     end
 end
 

test/linalg/cholesky.jl

@@ -13,15 +13,15 @@ function unary_ops_tests(a, ca, tol; n=size(a, 1))
     @test isposdef(ca)
     @test_throws KeyError ca[:Z]
     @test size(ca) == size(a)
-    @test Matrix(copy(ca)) ≈ a
+    @test Array(copy(ca)) ≈ a
 end
 
 function factor_recreation_tests(a_U, a_L)
     c_U = cholfact(a_U)
     c_L = cholfact(a_L)
     cl  = chol(a_L)
     ls = c_L[:L]
-    @test Matrix(c_U) ≈ Matrix(c_L) ≈ a_U
+    @test Array(c_U) ≈ Array(c_L) ≈ a_U
     @test ls*ls' ≈ a_U
     @test triu(c_U.factors) ≈ c_U[:U]
     @test tril(c_L.factors) ≈ c_L[:L]
@@ -180,6 +180,8 @@ end
                 C = cholfact(A)
                 @test !isposdef(C)
                 @test !LinAlg.issuccess(C)
+                Cstr = sprint(show, C)
+                @test Cstr == "Failed factorization of type $(typeof(C))"
                 @test_throws PosDefException C\B
                 @test_throws PosDefException det(C)
                 @test_throws PosDefException logdet(C)

test/linalg/tridiag.jl

@@ -288,7 +288,7 @@ guardsrand(123) do
                             invFsv = Fs\vv
                             x = Ts\vv
                             @test x ≈ invFsv
-                            @test Array(AbstractArray(Tldlt)) ≈ Fs
+                            @test Array(Tldlt) ≈ Fs
                         end
 
                         @testset "similar" begin