error.jl

# This file is a part of Julia. License is MIT: https://julialang.org/license

@testset "ExponentialBackOff" begin
    @test length(ExponentialBackOff(n=10)) == 10
    @test collect(ExponentialBackOff(n=10, first_delay=0.01))[1] == 0.01
    @test maximum(ExponentialBackOff(n=10, max_delay=0.06)) == 0.06
    ratio(x) = x[2:end]./x[1:end-1]
    @test all(x->x ≈ 10.0, ratio(collect(ExponentialBackOff(n=10, max_delay=Inf, factor=10, jitter=0.0))))
    Test.guardseed(12345) do
        x = ratio(collect(ExponentialBackOff(n=100, max_delay=Inf, factor=1, jitter=0.1)))
        xm = sum(x) / length(x)
        @test (xm - 1.0) < 1e-4
    end
end
@testset "retrying after errors" begin
    function foo_error(c, n)
        c[1] += 1
        if c[1] <= n
            error("foo")
        end
        return 7
    end

    # Success on first attempt
    c = [0]
    @test retry(foo_error)(c,0) == 7
    @test c[1] == 1

    # Success on second attempt
    c = [0]
    @test retry(foo_error)(c,1) == 7
    @test c[1] == 2

    # 2 failed retry attempts, so exception is raised
    c = [0]
    ex = try retry(foo_error, delays=ExponentialBackOff(n=2))(c,3) catch e; e end
    @test ex.msg == "foo"
    @test c[1] == 3

    c = [0]
    ex = try retry(foo_error, check=(s,e)->(s,isa(e, ErrorException)))(c,2) catch e; e end
    @test typeof(ex) == ErrorException
    @test ex.msg == "foo"
    @test c[1] == 2

    c = [0]
    ex = try retry(foo_error, check=(s,e)->(s,e.msg == "foo"))(c,2) catch e; e end
    @test typeof(ex) == ErrorException
    @test ex.msg == "foo"
    @test c[1] == 2

    # No retry if condition does not match
    c = [0]
    ex = try retry(foo_error, check=(s,e)->(s,e.msg == "bar"))(c,2) catch e; e end
    @test typeof(ex) == ErrorException
    @test ex.msg == "foo"
    @test c[1] == 1

    c = [0]
    ex = try retry(foo_error, check=(s,e)->(s,try e.http_status_code == "503"; catch; end != true))(c,2) catch e; e end
    @test typeof(ex) == ErrorException
    @test ex.msg == "foo"
    @test c[1] == 2

    c = [0]
    ex = try retry(foo_error, check=(s,e)->(s,isa(e,SystemError)))(c,2) catch e; e end
    @test typeof(ex) == ErrorException
    @test ex.msg == "foo"
    @test c[1] == 1

    # Test example in docstring where the check function doesn't return the state.
    c = [0]
    @test retry(foo_error, check=(s,e)->e.msg == "foo")(c,1) == 7
    @test c[1] == 2

    # Functions with keyword arguments
    foo_kwargs(x; y=5) = x + y
    @test retry(foo_kwargs)(3) == 8
    @test retry(foo_kwargs)(3; y=4) == 7
end