[codex] Add RunDevServer SIGTERM regression check

devenv-module.nix

@@ -148,6 +148,31 @@ that is defined in flake-module.nix
                         touch $out
                     '';
                 };
+
+                run-devserver-sigterm = pkgs.stdenv.mkDerivation {
+                    name = "run-devserver-sigterm";
+                    src = self;
+                    sourceRoot = "source";
+                    nativeBuildInputs = [
+                        (pkgs.ghc.ghc.withPackages (p: with p; [
+                            ihp ihp-ide ihp-schema-compiler
+                        ]))
+                        pkgs.gnumake
+                        pkgs.postgresql
+                        pkgs.procps
+                    ];
+                    buildPhase = ''
+                        export IHP_LIB=${self.packages.${system}.ihp-env-var-backwards-compat}
+                        export IHP_STATIC=${self.packages.${system}.ihp-static}
+                        export PS_BIN=${pkgs.procps}/bin/ps
+                        export RUN_DEVSERVER=${pkgs.ghc.ihp-ide}/bin/RunDevServer
+
+                        bash integration-test/run-devserver-sigterm-check.sh
+                    '';
+                    installPhase = ''
+                        touch $out
+                    '';
+                };
             }
 
             # GHC 9.12 compatibility checks (build and test all IHP packages)

integration-test/.ghci

@@ -0,0 +1,4 @@
+:set -XNoImplicitPrelude
+:def loadFromIHP \file -> (System.Environment.getEnv "IHP_LIB") >>= (\ihpLib -> readFile (ihpLib <> "/" <> file))
+:loadFromIHP applicationGhciConfig
+import IHP.Prelude

integration-test/Main.hs

@@ -0,0 +1,16 @@
+module Main where
+
+import IHP.Prelude
+import IHP.FrameworkConfig
+import qualified IHP.Server
+import IHP.Job.Types
+
+import Config
+import Web.FrontController ()
+import Web.SlowLoad ()
+
+instance Worker RootApplication where
+    workers _ = []
+
+main :: IO ()
+main = IHP.Server.run config

integration-test/Web/SlowLoad.hs

@@ -0,0 +1,12 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Web.SlowLoad where
+
+import Control.Concurrent (threadDelay)
+import Language.Haskell.TH.Syntax (Dec, runIO)
+import Prelude (Int, pure, (*))
+
+$(do
+    -- Keep GHCi in the initial :l Main.hs load long enough for the SIGTERM
+    -- regression check to hit the orphaning window deterministically.
+    runIO (threadDelay (10 * (1000000 :: Int)))
+    pure ([] :: [Dec]))

integration-test/run-devserver-sigterm-check.sh

@@ -0,0 +1,99 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+app_dir="$(pwd)/integration-test"
+log_file="${TMPDIR:-/tmp}/run-devserver.log"
+devserver_pid=""
+ghci_pid=""
+ps_bin="${PS_BIN:-ps}"
+
+cleanup() {
+    if [ -n "${ghci_pid:-}" ] && kill -0 "$ghci_pid" 2>/dev/null; then
+        kill -KILL "$ghci_pid" 2>/dev/null || true
+    fi
+
+    if [ -n "${devserver_pid:-}" ] && kill -0 "$devserver_pid" 2>/dev/null; then
+        kill -KILL "$devserver_pid" 2>/dev/null || true
+    fi
+
+    if [ -n "${PGDATA:-}" ]; then
+        pg_ctl -D "$PGDATA" stop >/dev/null 2>&1 || true
+    fi
+}
+trap cleanup EXIT
+
+find_ghci_child() {
+    "$ps_bin" -axo pid=,ppid=,command= | awk -v ppid="$devserver_pid" '
+        $2 == ppid && $0 ~ /--interactive/ { print $1; exit }
+    '
+}
+
+export HOME="${TMPDIR:-/tmp}/home"
+mkdir -p "$HOME"
+
+export PGDATA="${TMPDIR:-/tmp}/pgdata"
+export PGHOST="${TMPDIR:-/tmp}/pghost"
+mkdir -p "$PGHOST"
+initdb -D "$PGDATA" --no-locale --encoding=UTF8
+echo "unix_socket_directories = '$PGHOST'" >> "$PGDATA/postgresql.conf"
+echo "listen_addresses = ''" >> "$PGDATA/postgresql.conf"
+pg_ctl -D "$PGDATA" -l "${TMPDIR:-/tmp}/pg.log" start
+createdb -h "$PGHOST" app
+
+export DATABASE_URL="postgresql:///app?host=$PGHOST"
+export IHP_BROWSER=true
+
+cd "$app_dir"
+"$RUN_DEVSERVER" >"$log_file" 2>&1 &
+devserver_pid="$!"
+
+for _ in $(seq 1 200); do
+    ghci_pid="$(find_ghci_child || true)"
+    if [ -n "$ghci_pid" ]; then
+        break
+    fi
+    sleep 0.1
+done
+
+if [ -z "$ghci_pid" ]; then
+    echo "RunDevServer never spawned the GHCi child" >&2
+    cat "$log_file" >&2
+    exit 1
+fi
+
+sleep 1
+
+if grep -Eq 'modules (loaded|reloaded)\.|Server started' "$log_file"; then
+    echo "RunDevServer reached steady state before SIGTERM; fixture is too fast" >&2
+    cat "$log_file" >&2
+    exit 1
+fi
+
+kill -TERM "$devserver_pid"
+
+for _ in $(seq 1 100); do
+    if ! kill -0 "$devserver_pid" 2>/dev/null; then
+        break
+    fi
+    sleep 0.1
+done
+
+if kill -0 "$devserver_pid" 2>/dev/null; then
+    echo "RunDevServer did not exit after SIGTERM" >&2
+    cat "$log_file" >&2
+    exit 1
+fi
+
+for _ in $(seq 1 20); do
+    if ! kill -0 "$ghci_pid" 2>/dev/null; then
+        break
+    fi
+    sleep 0.1
+done
+
+if kill -0 "$ghci_pid" 2>/dev/null; then
+    echo "Orphaned GHCi process survived RunDevServer SIGTERM" >&2
+    "$ps_bin" -o pid=,ppid=,command= -p "$ghci_pid" >&2 || true
+    cat "$log_file" >&2
+    exit 1
+fi