Fix test seeding on 1.11+

Author: JamesWrigley

src/ReTest.jl

@@ -575,6 +575,10 @@ const ArgType = Union{Module,PatternX,AbstractString,AbstractArray,Tuple,Symbol,
                       Pair{Module,
                            <:Union{PatternX,AbstractString,AbstractArray,Tuple}}}
 
+# Holds the seed to set before each testset. This is not thread-safe, but it's
+# not normal/intended to call retest() concurrently anyway.
+const test_seed = Ref{Any}(false)
+
 const retest_defaults = (
     dry       = false,
     stats     = false,
@@ -1089,22 +1093,12 @@ function retest(@nospecialize(args::ArgType...);
             end
 
             if seed !== false
-                let seedstr =
-                        if seed === true
-                            # seed!(nothing) doesn't work on old Julia, so we can't just set
-                            # `seed = nothing` and interpolate `seed` directly in includestr
-                            ""
-                        else
-                            string(seed)
-                        end,
-                    includestr = """
-                                 using Random
-                                 Random.seed!($seedstr)
-                                 nothing
-                                 """
-                    # can't use `@everywhere using Random`, as here is not toplevel
-                    @everywhere Base.include_string(Main, $includestr)
-                end
+                includestr = """
+                import ReTest
+                ReTest.test_seed[] = $seed
+                """
+
+                @everywhere Base.include_string(Main, $includestr)
             end
 
             @sync for wrkr in workers()

src/testset.jl

@@ -14,6 +14,7 @@ using Distributed: myid, nworkers
 
 import InlineTest: @testset
 
+import ..ReTest
 using ..ReTest: Pattern, Marks, matches, setresult!
 
 # mostly copied from Test stdlib
@@ -514,17 +515,19 @@ function testset_beginend(mod::Module, isfinal::Bool, pat::Pattern, id::Int64, d
                 put!($(chan.preview), ($id, $desc))
             end
             push_testset(ts)
+
             # we reproduce the logic of guardseed, but this function
             # cannot be used as it changes slightly the semantic of @testset,
             # by wrapping the body in a function
-            local RNG = default_rng()
-            local oldrng = copy(RNG)
+            local default_rng_orig = copy(default_rng())
+            @static if VERSION >= v"1.11"
+                local tls_seed_orig = copy(Random.get_tls_seed())
+            end
+
             try
-                # RNG is re-seeded with its own seed to ease reproduce a failed test
-                if VERSION >= v"1.7.0-DEV.1225"
-                    Random.seed!(Random.GLOBAL_SEED)
-                else
-                    Random.seed!(RNG.seed)
+                # RNG is re-seeded with the desired seed for the test
+                if ReTest.test_seed[] !== false
+                    Random.seed!(ReTest.test_seed[])
                 end
                 let
                     ts.timed = @stats $stats $(esc(tests))
@@ -536,14 +539,19 @@ function testset_beginend(mod::Module, isfinal::Bool, pat::Pattern, id::Int64, d
                 record(ts, Error(:nontest_error, Expr(:tuple), err,
                                  current_exceptions(), $(QuoteNode(source))))
             finally
-                copy!(RNG, oldrng)
+                copy!(default_rng(), default_rng_orig)
+                @static if VERSION >= v"1.11"
+                    copy!(Random.get_tls_seed(), tls_seed_orig)
+                end
+
                 setresult!($marks, ts.subject, !anyfailed(ts))
                 pop_testset()
                 ret = finish(ts, $chan)
             end
             ret
         end
     end
+
     # preserve outer location if possible
     if tests isa Expr && tests.head === :block &&
         !isempty(tests.args) && tests.args[1] isa LineNumberNode
@@ -578,7 +586,7 @@ function testset_forloop(mod::Module, isfinal::Bool, pat::Pattern, id::Int64,
                     break
                 end
                 # it's 1000 times faster to copy from tmprng rather than calling Random.seed!
-                copy!(RNG, tmprng)
+                copy!(default_rng(), tmprng)
             end
             ts = ts0
             if nworkers() == 1 && get_testset_depth() == 0 && $(chan.preview) !== nothing
@@ -600,19 +608,22 @@ function testset_forloop(mod::Module, isfinal::Bool, pat::Pattern, id::Int64,
             end
         end
     end
+
     quote
         local arr = Vector{Any}()
         local first_iteration = true
         local iter = 0
         local ts
-        local RNG = default_rng()
-        local oldrng = copy(RNG)
-        if VERSION >= v"1.7.0-DEV.1225"
-            Random.seed!(Random.GLOBAL_SEED)
-        else
-            Random.seed!(RNG.seed)
+
+        local default_rng_orig = copy(default_rng())
+        @static if VERSION >= v"1.11"
+            local tls_seed_orig = copy(Random.get_tls_seed())
+        end
+
+        local tmprng = copy(default_rng())
+        if ReTest.test_seed[] !== false
+            tmprng = copy(Random.seed!(ReTest.test_seed[]))
         end
-        local tmprng = copy(RNG)
         try
             let
                 $(Expr(:for, Expr(:block, [esc(v) for v in loops]...), blk))
@@ -623,7 +634,11 @@ function testset_forloop(mod::Module, isfinal::Bool, pat::Pattern, id::Int64,
                 pop_testset()
                 push!(arr, finish(ts, $chan))
             end
-            copy!(RNG, oldrng)
+
+            copy!(default_rng(), default_rng_orig)
+            @static if VERSION >= v"1.11"
+                copy!(Random.get_tls_seed(), tls_seed_orig)
+            end
         end
         arr
     end