Test: improve type stabilities (#59082)

Also simplifies code a bit, by removing unnecessary branches.

Author: aviatesk

stdlib/Test/src/Test.jl

@@ -217,14 +217,19 @@ struct Error <: Result
     context::Union{Nothing, String}
     source::LineNumberNode
 
-    function Error(test_type::Symbol, orig_expr, value, bt, source::LineNumberNode, context::Union{Nothing, String}=nothing)
-        if test_type === :test_error
-            bt = scrub_exc_stack(bt, nothing, extract_file(source))
-        end
-        if test_type === :test_error || test_type === :nontest_error
-            bt_str = try # try the latest world for this, since we might have eval'd new code for show
+    function Error(test_type::Symbol, orig_expr, value, excs::Union{Base.ExceptionStack,Nothing},
+                   source::LineNumberNode, context::Union{Nothing, String}=nothing)
+        @nospecialize orig_expr value
+        bt_str = ""
+        if !isnothing(excs)
+            if test_type === :test_error
+                excs = scrub_exc_stack(excs, nothing, extract_file(source))
+            end
+            if test_type === :test_error || test_type === :nontest_error
+                bt_str = try
+                    # try the latest world for this, since we might have eval'd new code for show
                     # Apply REPL backtrace scrubbing to hide REPL internals, similar to how REPL.jl handles it
-                    Base.invokelatest(sprint, Base.show_exception_stack, Base.scrub_repl_backtrace(bt); context=stdout)
+                    Base.invokelatest(sprint, Base.show_exception_stack, Base.scrub_repl_backtrace(excs); context=stdout)
                 catch ex
                     "#=ERROR showing exception stack=# " *
                         try
@@ -233,8 +238,7 @@ struct Error <: Result
                             "of type " * string(typeof(ex))
                         end
                 end
-        else
-            bt_str = ""
+            end
         end
         value = try # try the latest world for this, since we might have eval'd new code for show
                 Base.invokelatest(sprint, show, value, context = :limit => true)
@@ -346,7 +350,7 @@ end
 
 struct Threw <: ExecutionResult
     exception
-    backtrace::Union{Nothing,Vector{Any}}
+    current_exceptions::Base.ExceptionStack
     source::LineNumberNode
 end
 
@@ -746,7 +750,7 @@ end
 
 # An internal function, called by the code generated by the @test
 # macro to actually perform the evaluation and manage the result.
-function do_test(result::ExecutionResult, orig_expr)
+function do_test(result::ExecutionResult, @nospecialize orig_expr)
     # get_testset() returns the most recently added test set
     # We then call record() with this test set and the test result
     if isa(result, Returned)
@@ -768,13 +772,13 @@ function do_test(result::ExecutionResult, orig_expr)
         # The predicate couldn't be evaluated without throwing an
         # exception, so that is an Error and not a Fail
         @assert isa(result, Threw)
-        testres = Error(:test_error, orig_expr, result.exception, result.backtrace::Vector{Any}, result.source, nothing)
+        testres = Error(:test_error, orig_expr, result.exception, result.current_exceptions, result.source, nothing)
     end
     isa(testres, Pass) || trigger_test_failure_break(result)
     record(get_testset(), testres)
 end
 
-function do_broken_test(result::ExecutionResult, orig_expr)
+function do_broken_test(result::ExecutionResult, @nospecialize orig_expr)
     testres = Broken(:test, orig_expr)
     # Assume the test is broken and only change if the result is true
     if isa(result, Returned)
@@ -860,7 +864,7 @@ end
 
 # An internal function, called by the code generated by @test_throws
 # to evaluate and catch the thrown exception - if it exists
-function do_test_throws(result::ExecutionResult, orig_expr, extype)
+function do_test_throws(result::ExecutionResult, @nospecialize(orig_expr), extype)
     if isa(result, Threw)
         # Check that the right type of exception was thrown
         success = false
@@ -908,20 +912,17 @@ function do_test_throws(result::ExecutionResult, orig_expr, extype)
         if success
             testres = Pass(:test_throws, orig_expr, extype, exc, result.source, message_only)
         else
-            if result.backtrace !== nothing
-                bt = scrub_exc_stack(result.backtrace, nothing, extract_file(result.source))
-                bt_str = try # try the latest world for this, since we might have eval'd new code for show
-                    Base.invokelatest(sprint, Base.show_exception_stack, bt; context=stdout)
-                catch ex
-                    "#=ERROR showing exception stack=# " *
-                        try
-                            sprint(Base.showerror, ex, catch_backtrace(); context=stdout)
-                        catch
-                            "of type " * string(typeof(ex))
-                        end
-                end
-            else
-                bt_str = nothing
+            excs = result.current_exceptions
+            bt = scrub_exc_stack(excs, nothing, extract_file(result.source))
+            bt_str = try # try the latest world for this, since we might have eval'd new code for show
+                Base.invokelatest(sprint, Base.show_exception_stack, bt; context=stdout)
+            catch ex
+                "#=ERROR showing exception stack=# " *
+                    try
+                        sprint(Base.showerror, ex, catch_backtrace(); context=stdout)
+                    catch
+                        "of type " * string(typeof(ex))
+                    end
             end
             testres = Fail(:test_throws_wrong, orig_expr, extype, exc, nothing, result.source, message_only, bt_str)
         end
@@ -1073,7 +1074,7 @@ end
 A simple fallback test set that throws immediately on a failure.
 """
 struct FallbackTestSet <: AbstractTestSet end
-fallback_testset = FallbackTestSet()
+const fallback_testset = FallbackTestSet()
 
 struct FallbackTestSetException <: Exception
     msg::String

stdlib/Test/test/runtests.jl

@@ -390,7 +390,7 @@ let retval_tests = @testset NoThrowTestSet begin
         ts = Test.DefaultTestSet("Mock for testing retval of record(::DefaultTestSet, ::T <: Result) methods")
         pass_mock = Test.Pass(:test, 1, 2, 3, LineNumberNode(0, "A Pass Mock"))
         @test Test.record(ts, pass_mock) isa Test.Pass
-        error_mock = Test.Error(:test, 1, 2, 3, LineNumberNode(0, "An Error Mock"), nothing)
+        error_mock = Test.Error(:test, 1, 2, nothing, LineNumberNode(0, "An Error Mock"), nothing)
         @test Test.record(ts, error_mock; print_result=false) isa Test.Error
         fail_mock = Test.Fail(:test, 1, 2, 3, nothing, LineNumberNode(0, "A Fail Mock"), false)
         @test Test.record(ts, fail_mock; print_result=false) isa Test.Fail

test/runtests.jl

@@ -414,7 +414,7 @@ cd(@__DIR__) do
             # deserialization errors or something similar.  Record this testset as Errored.
             fake = Test.DefaultTestSet(testname)
             fake.time_end = fake.time_start + duration
-            Test.record(fake, Test.Error(:nontest_error, testname, nothing, Any[(resp, [])], LineNumberNode(1), nothing))
+            Test.record(fake, Test.Error(:nontest_error, testname, nothing, Base.ExceptionStack(Any[(resp, [])]), LineNumberNode(1), nothing))
             Test.push_testset(fake)
             Test.record(o_ts, fake)
             Test.pop_testset()
@@ -423,7 +423,7 @@ cd(@__DIR__) do
     for test in all_tests
         (test in completed_tests) && continue
         fake = Test.DefaultTestSet(test)
-        Test.record(fake, Test.Error(:test_interrupted, test, nothing, [("skipped", [])], LineNumberNode(1), nothing))
+        Test.record(fake, Test.Error(:test_interrupted, test, nothing, Base.ExceptionStack(Any[("skipped", [])]), LineNumberNode(1), nothing))
         Test.push_testset(fake)
         Test.record(o_ts, fake)
         Test.pop_testset()