Couple of bug fixes related to the status printing

src/ParallelTestRunner.jl

@@ -280,7 +280,7 @@ function print_test_failed(record::AbstractTestRecord, wrkr, test, ctx::TestIOCo
 
         if ctx.verbose
             init_time_str = @sprintf("%7.2f", base.total_time - base.time)
-            printstyled(ctx.stdout, lpad(init_time_str, ctx.elapsed_align + 1, " "), " │ ", color = :red)
+            printstyled(ctx.stderr, lpad(init_time_str, ctx.elapsed_align + 1, " "), " │ ", color = :red)
         end
 
         failed_str = "failed at $(now())\n"
@@ -313,6 +313,14 @@ function print_test_crashed(::Type{<:AbstractTestRecord}, wrkr, test, ctx::TestI
     end
 end
 
+# Truncate `line` to at most `max_width` characters, appending "..." when truncated.
+function truncate_line(line::AbstractString, max_width::Int)
+    if length(line) > max_width
+        line = first(line, max(0, max_width - 3)) * "..."
+    end
+    return line
+end
+
 # Adapted from `Malt._stdio_loop`
 function stdio_loop(worker::Malt.Worker, io::Lockable)
     Threads.@spawn while !eof(worker.stdout) && Malt.isrunning(worker)
@@ -1191,9 +1199,7 @@ function _runtests(mod::Module, args::ParsedArgs;
         line2 = "Running:  " * join(status_parts, ", ")
         ## truncate
         max_width = displaysize(io_ctx.stdout)[2]
-        if length(line2) > max_width
-            line2 = line2[1:max_width-3] * "..."
-        end
+        line2 = truncate_line(line2, max_width)
 
         # line 3: progress + ETA
         line3 = "Progress: $completed/$total tests completed"

test/runtests.jl

@@ -346,6 +346,30 @@ end
     @test contains(str, "1 == 2")
 end
 
+@testset "failed test row printed entirely to stderr" begin
+    testsuite = Dict(
+        "failing test" => quote
+            @test 1 == 2
+        end
+    )
+
+    # use separate streams: the whole row of a failed test must go to stderr
+    out = IOBuffer()
+    err = IOBuffer()
+    @test_throws Test.FallbackTestSetException("Test run finished with errors") begin
+        runtests(ParallelTestRunner, ["--verbose"]; testsuite, stdout=out, stderr=err)
+    end
+
+    outs = String(take!(out))
+    errs = String(take!(err))
+    m = match(r"failing test[^\n]*failed at", errs)
+    @test m !== nothing
+    # in verbose mode the row has three cell separators (time, init time) on
+    # stderr; the init-time cell used to leak to stdout instead
+    @test m !== nothing && count("│", m.match) == 3
+    @test !contains(outs, "failed at")
+end
+
 @testset "nested failure" begin
     testsuite = Dict(
         "nested" => quote
@@ -884,6 +908,26 @@ end
     @test any(contains("--color=yes"), exe.exec)
 end
 
+@testset "truncate_line" begin
+    # short lines are untouched
+    @test ParallelTestRunner.truncate_line("short", 80) == "short"
+    @test ParallelTestRunner.truncate_line("x"^80, 80) == "x"^80
+
+    truncated = ParallelTestRunner.truncate_line("x"^100, 80)
+    @test length(truncated) == 80
+    @test endswith(truncated, "...")
+
+    # multi-byte characters must not break the cut: with byte indexing these
+    # would throw a StringIndexError when the cut lands mid-character
+    truncated = ParallelTestRunner.truncate_line("t" * "α"^100, 80)
+    @test length(truncated) == 80
+    @test endswith(truncated, "...")
+
+    truncated = ParallelTestRunner.truncate_line("€"^100, 40)
+    @test length(truncated) == 40
+    @test endswith(truncated, "...")
+end
+
 @testset "TestHistoryEntry" begin
     flow = ParallelTestRunner.TestHistoryEntry(1,true)
     fhigh = ParallelTestRunner.TestHistoryEntry(10,true)