oneunit of sparse matrix should return sparse matrix (#30228)

* added sprandn methods with Type

* oneunit of sparse matrix should return sparse array

Author: KlausC

stdlib/SparseArrays/src/sparsematrix.jl

@@ -1524,7 +1524,8 @@ function spzeros(::Type{Tv}, ::Type{Ti}, sz::Tuple{Integer,Integer}) where {Tv,
     spzeros(Tv, Ti, sz[1], sz[2])
 end
 
-function one(S::SparseMatrixCSC{T}) where T
+import Base._one
+function Base._one(unit::T, S::SparseMatrixCSC) where T
     S.m == S.n || throw(DimensionMismatch("multiplicative identity only defined for square matrices"))
     return SparseMatrixCSC{T}(I, S.m, S.n)
 end

stdlib/SparseArrays/test/sparse.jl

@@ -9,6 +9,7 @@ using Base.Printf: @printf
 using Random
 using Test: guardseed
 using InteractiveUtils: @which
+using Dates
 
 @testset "issparse" begin
     @test issparse(sparse(fill(1,5,5)))
@@ -2350,4 +2351,12 @@ end
     @test success(pipeline(cmd; stdout=stdout, stderr=stderr))
 end
 
+@testset "oneunit of sparse matrix" begin
+    A = sparse([Second(0) Second(0); Second(0) Second(0)])
+    @test oneunit(sprand(2, 2, 0.5)) isa SparseMatrixCSC{Float64}
+    @test oneunit(A) isa SparseMatrixCSC{Second}
+    @test one(sprand(2, 2, 0.5)) isa SparseMatrixCSC{Float64}
+    @test one(A) isa SparseMatrixCSC{Int}
+end
+
 end # module