tests: every test dir is removed when its test ends, pass or panic

Many test helpers removed their temp dir only before the test, or only
on pass, so runs left them behind: 117,000 filled /tmp (RAM here) and
stopped a mutation run. Each now holds a guard that removes the dir on
drop, unwind included; servers started on a test dir hold its guard
until they stop. A full cargo test --workspace leaves 0 dirs (859
before). just sweep-test-tmp stays for runs killed mid-test.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

crates/ledger-gui/tests/view_model.rs

@@ -51,14 +51,31 @@ fn plan() -> impl Strategy<Value = Plan> {
         })
 }
 
-fn dir(tag: &str) -> PathBuf {
+/// A test's dir, removed when the test ends, pass or panic.
+struct TestDir(PathBuf);
+
+impl std::ops::Deref for TestDir {
+    type Target = std::path::Path;
+    fn deref(&self) -> &std::path::Path {
+        &self.0
+    }
+}
+
+impl Drop for TestDir {
+    fn drop(&mut self) {
+        let _ = std::fs::remove_dir_all(&self.0);
+    }
+}
+
+fn dir(tag: &str) -> TestDir {
     let d = std::env::temp_dir().join(format!("ledger-gui-vm-{}-{tag}", std::process::id()));
     let _ = std::fs::remove_dir_all(&d);
     std::fs::create_dir_all(&d).unwrap();
-    d
+    TestDir(d)
 }
 
-fn build(plan: &Plan, tag: &str) -> (Source, ledger_core::Ledger) {
+/// The books, where they are (kept while the guard lives), and their ledger.
+fn build(plan: &Plan, tag: &str) -> (TestDir, Source, ledger_core::Ledger) {
     let d = dir(tag);
     let mut s = Store::create(&d.join("books-data"), Currency::USD).unwrap();
     let ids: Vec<_> = CHART
@@ -81,14 +98,12 @@ fn build(plan: &Plan, tag: &str) -> (Source, ledger_core::Ledger) {
     )
     .unwrap();
     let ledger = s.ledger().clone();
-    (
-        Source {
-            data_dir: d.join("books-data"),
-            books_toml: Some(d.join("wanderbooks.toml")),
-            today: Some(plan.today),
-        },
-        ledger,
-    )
+    let source = Source {
+        data_dir: d.join("books-data"),
+        books_toml: Some(d.join("wanderbooks.toml")),
+        today: Some(plan.today),
+    };
+    (d, source, ledger)
 }
 
 /// An account's normal-side balance at the end of `date`, from the trial
@@ -122,7 +137,7 @@ proptest! {
     /// Kpis INVARIANTS 1-7 and the period helpers, against ledger-core.
     #[test]
     fn the_overview_numbers_are_the_books_numbers(p in plan()) {
-        let (source, l) = build(&p, "kpi");
+        let (_dir, source, l) = build(&p, "kpi");
         let b = data::load_once(&source).unwrap();
         let k = &b.kpis;
         let t = p.today;
@@ -283,7 +298,6 @@ fn origins_and_parties() {
     assert_eq!(std::fs::read(path).unwrap(), b"%PDF receipt");
     assert_eq!(b.integrity.files_ok, 1);
     assert!(b.integrity.file_failures.is_empty());
-    let _ = std::fs::remove_dir_all(&d);
 }
 
 /// fmt helpers the viewer shows: percent change and tax forms.
@@ -306,7 +320,7 @@ fn percent_change_and_tax_forms() {
     assert_eq!(fmt::compact(d("-1234")), "\u{2212}$1.2k");
 }
 
-fn store_at(tag: &str) -> (PathBuf, Store) {
+fn store_at(tag: &str) -> (TestDir, Store) {
     let d = dir(tag);
     let s = Store::create(&d.join("books-data"), Currency::USD).unwrap();
     (d, s)
@@ -476,9 +490,6 @@ fn comparisons_and_burn_on_fixed_dates() {
     drop(s5);
     let b5 = data::load_once(&source(&d5, "", today)).unwrap();
     assert_eq!(b5.kpis.monthly_burn, None);
-    for x in [d, d2, d3, d4, d5] {
-        let _ = std::fs::remove_dir_all(x);
-    }
 }
 
 /// The view model's indexes: cash accounts by name when the settings name
@@ -548,7 +559,6 @@ fn indexes_cash_cards_accounts_and_fresh() {
     let integrity = ledger_gui::books::Integrity::check(&snap, &mut verified);
     let b2 = ledger_gui::books::Books::build(&snap, settings, today, Some(seq), integrity).unwrap();
     assert_eq!(b2.fresh, [e2].into_iter().collect());
-    let _ = std::fs::remove_dir_all(&d);
 }
 
 /// Integrity counts every stored file, read once: a second check with the
@@ -580,7 +590,6 @@ fn integrity_counts_files_once_verified() {
     assert_eq!((first.files_ok, first.file_failures.len()), (2, 0));
     let again = ledger_gui::books::Integrity::check(&snap, &mut verified);
     assert_eq!((again.files_ok, again.file_failures.len()), (2, 0));
-    let _ = std::fs::remove_dir_all(&d);
 }
 
 /// Origins and parties for the rest of the journal's kinds: the invoice
@@ -647,5 +656,4 @@ fn more_origins_and_parties() {
     let r = b.entry(remit).unwrap();
     assert_eq!(r.origin, "Payroll taxes");
     assert!(!r.missing_receipt, "a remittance isn't a hand-made entry");
-    let _ = std::fs::remove_dir_all(&d);
 }