From 73a705efe4005dc491e7a055e1104f4c0ed28f95 Mon Sep 17 00:00:00 2001
From: "Jonathan D.A. Jewell" <6759885+hyperpolymath@users.noreply.github.com>
Date: Tue, 21 Jul 2026 07:19:47 +0100
Subject: [PATCH] fix(tests): e2e.sh discarded all mix test output, making CI
 undebuggable
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`tests/e2e.sh` judged the Elixir suite with:

    mix test --trace 2>&1 | tail -5 | grep -q "0 failures"

The pipe threw the entire run away. When the suite failed, CI printed exactly
one line:

    FAIL: Elixir unit tests
    Results: PASS=7  FAIL=1  SKIP=0

No failing test name, no assertion, no stacktrace. The `E2E — Elixir Scanner
Pipeline` job has been red on main with literally nothing to diagnose from.

Now: capture the run to a log, judge it by mix's own exit status (mix already
exits non-zero on failure — the `grep "0 failures"` was a weaker proxy that
also mis-reports a crash that never reaches the summary line), and echo the
tail of the output when it fails.

Verified by stubbing a failing `mix` and confirming the diagnostic surfaces:

    FAIL: Elixir unit tests
    --- mix test output (tail 120) ---
      1) test foo (Hypatia.ReflexiveTest)
         ** (exit) no process
    --- end mix test output ---

bash -n clean; shellcheck reports nothing on the new block.

What this immediately reveals (reproduced locally, Elixir 1.18.3/OTP 27):
`mix test` = 1398 tests, 20 failures, ALL in test/reflexive_test.exs, all
`GenServer.call(Hypatia.Supervisor, {:terminate_child, ...})` -> "no process
... possibly because its application isn't started". Running that file ALONE
gives 16 tests, 0 failures — so it is a test-isolation defect, not a product
bug. Filed separately; this commit only makes it visible.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 tests/e2e.sh | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/tests/e2e.sh b/tests/e2e.sh
index 8153ecd9..4b1ef6c9 100755
--- a/tests/e2e.sh
+++ b/tests/e2e.sh
@@ -114,12 +114,24 @@ if $HAS_ELIXIR; then
         fi
     fi
 
-    # Unit tests
-    if mix test --trace 2>&1 | tail -5 | grep -q "0 failures"; then
+    # Unit tests.
+    #
+    # Previously this was `mix test --trace 2>&1 | tail -5 | grep -q "0 failures"`,
+    # which DISCARDED the entire test output. A CI failure therefore reported
+    # exactly one line — "FAIL: Elixir unit tests" — with no failing test name,
+    # no assertion, no stacktrace, making the red job impossible to diagnose
+    # from CI. Capture the run, judge it by mix's own exit status, and echo the
+    # output when it fails.
+    _mix_log="${TMPDIR:-/tmp}/hypatia-mix-test.$$.log"
+    if mix test --trace >"$_mix_log" 2>&1; then
         pass "Elixir unit tests pass"
     else
         fail_test "Elixir unit tests"
+        echo "--- mix test output (tail 120) ---"
+        tail -120 "$_mix_log"
+        echo "--- end mix test output ---"
     fi
+    rm -f "$_mix_log"
 
     echo ""
 fi