avoid writing into package depot dir

Author: tanmaykm

test/runtests_routeguide.jl

@@ -49,10 +49,13 @@ end
 function test_generate()
     @testset "codegen" begin
         dir = joinpath(@__DIR__, "RouteguideClients")
-        gRPCClient.generate(joinpath(dir, "route_guide.proto"); outdir=dir)
-        @test isfile(joinpath(dir, "route_guide_pb.jl"))
-        @test isfile(joinpath(dir, "routeguide.jl"))
-        @test isfile(joinpath(dir, "RouteguideClients.jl"))
+        # generate into tempdir to avoid writing inside depot folder
+        mktempdir() do outdir
+            gRPCClient.generate(joinpath(dir, "route_guide.proto"); outdir=outdir)
+            @test isfile(joinpath(dir, "route_guide_pb.jl"))
+            @test isfile(joinpath(dir, "routeguide.jl"))
+            @test isfile(joinpath(dir, "RouteguideClients.jl"))
+        end
     end
 end