ideas

SHOUT.md

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+# Shout — Proposed Improvements
+
+Two additions to the shout test framework: automatic process cleanup and test isolation primitives.
+
+## 1. Automatic Process Cleanup
+
+### Problem
+
+Any test that backgrounds a process (`&`) must manually clean it up. If a test fails or times out before reaching its cleanup command, the process is orphaned and holds its port indefinitely. Every test author has to remember the `trap` pattern:
+
+```
+$ my-server &; SVR=$!; trap "kill $SVR 2>/dev/null" EXIT; ...
+```
+
+This is error-prone and noisy.
+
+### Proposal
+
+Shout already owns the shell process (via `Bun.spawn`). After the shell exits, shout should kill the entire process group to reap any lingering children.
+
+In `run.ts`, after the shell completes:
+
+```ts
+// Kill the shell's process group to clean up backgrounded children
+try {
+  process.kill(-proc.pid, "SIGTERM")
+} catch {}
+```
+
+The `-pid` syntax sends the signal to the entire process group. Since shout spawns the shell, the shell and all its children share a process group.
+
+This requires no syntax changes, no test file modifications, and no action from test authors. Background a process, forget about it — shout cleans up.
+
+For defense in depth, follow up with SIGKILL after a short grace period:
+
+```ts
+try {
+  process.kill(-proc.pid, "SIGTERM")
+} catch {}
+setTimeout(() => {
+  try { process.kill(-proc.pid, "SIGKILL") } catch {}
+}, 500)
+```
+
+### Migration
+
+Remove the manual `kill` / `trap` lines from existing test files. They become no-ops but add visual noise.
+
+## 2. Test Isolation Primitives
+
+### Problem
+
+Every test file that needs a server repeats the same boilerplate:
+
+```
+$ PORT=19001 ... dev-server > /dev/null 2>&1 & SVR=$!; trap "kill $SVR 2>/dev/null" EXIT; i=0; while ! curl -sf http://localhost:19001/...; do ...; done; echo "ok"
+ok
+
+$ mkdir -p .config/dev && echo '{"server":"http://localhost:19001",...}' > .config/dev/config.json
+```
+
+Each test picks a hardcoded port. Adding a new test means manually checking which ports are taken. Parallel test runs risk port collisions.
+
+### Proposal: `# setup` directive
+
+A new directive that includes commands from a shared file before the test's own commands:
+
+```
+# setup tests/setup.shout
+```
+
+The setup file is a normal `.shout` file. Its commands are prepended to the test's script (same shell, same working directory, same environment). This is purely textual inclusion — no new execution model.
+
+Example `tests/setup.shout`:
+
+```
+$ dev-server > /dev/null 2>&1 &
+$ mkdir -p .config/dev && echo "{\"server\":\"http://localhost:$PORT\",\"token\":\"dev-token-1\"}" > .config/dev/config.json
+$ i=0; while ! curl -sf http://localhost:$PORT/api/whoami -H "Authorization: Bearer dev-token-1" > /dev/null 2>&1; do i=$((i+1)); if [ $i -gt 30 ]; then echo "server failed"; exit 1; fi; sleep 0.2; done; echo "ok"
+ok
+```
+
+Then a test file becomes:
+
+```
+# Phase 1 — Linear Timeline
+# setup tests/setup.shout
+
+$ dev init myapp
+initialized repo myapp in ./myapp
+
+$ cd myapp
+...
+```
+
+### Proposal: `--port-from <N>` flag
+
+A CLI flag that auto-assigns ports to test files:
+
+```sh
+shout --port-from 19000 tests/
+```
+
+Shout sets `$PORT` in each test file's environment, incrementing from the base. When `--parallel` is used, each file gets a unique port with no coordination needed.
+
+Implementation in the runner:
+
+```ts
+let nextPort = options.portFrom
+for (const file of files) {
+  const env = { ...baseEnv, PORT: String(nextPort++) }
+  await runFile(file, { ...options, env })
+}
+```
+
+Test files reference `$PORT` instead of hardcoded values. Combined with `# setup`, the per-file boilerplate drops to one line.
+
+### Proposal: `# env` directive
+
+For cases simpler than `# setup` — setting environment variables without a separate file:
+
+```
+# env PORT=19001
+# env NODE_ENV=production
+```
+
+These are injected into the shell environment before any commands run. Lighter than a setup file when all you need is a few variables.