test(config): pin what every enum setting is spelled as on disk

a_config_round_trips_every_field checks bools and numbers and skips strings on purpose, because de_lenient falls back to the default for a spelling it does not know. That is right for a file a human may have mistyped, and it is exactly what makes a rename invisible: the value does not fail to load, the setting is forgotten and the user finds their choice reverted with nothing said. The wire has the same guard already; this is the disk's copy of it. Fifteen enums, forty-nine variants, two rename rules between them. The strings were read out of serde rather than derived from the rename_all, which is how RightPanelTab::Scm turned out to be "changes" — a rename whose own doc explains it was done in place so an older build could still read the file back. Someone tidying that enum would undo it and kick every user off the panel they were on. Both directions are asserted, since an alias can make a variant readable under a name it is no longer written as. Checked by tidying the rename away: fails with left "scm", right "changes". My first attempt at that mutation edited the word in the doc comment instead of the attribute and the test passed — a mutation that does not mutate proves nothing, which is why the second one names what it changed.
2026-09-21 16:02:20 +00:00 · 2026-08-23 20:02:10 +08:00
parent e339848d5a
commit ef1e9bcee8
1 changed files with 77 additions and 0 deletions
@@ -3016,4 +3016,81 @@ mod tests {
        assert!(p.ends_with("config.json"));
        assert_eq!(p.parent(), config_dir_path().as_deref());
    }
+
+    /// What every enum setting is spelled as on disk, pinned.
+    ///
+    /// `a_config_round_trips_every_field` next door checks bools and numbers
+    /// and skips strings on purpose, because `de_lenient` falls back to the
+    /// default for a spelling it does not know. That is the right behaviour
+    /// for a config a human may have mistyped, and it is exactly what makes a
+    /// rename here invisible: the value does not fail to load, the setting is
+    /// simply forgotten and the user finds their choice reverted with nothing
+    /// said. The wire has `the_wire_spelling_of_every_simple_enum_variant_is_pinned`
+    /// for the same reason; this is the disk's copy of it.
+    ///
+    /// The strings were read out of serde rather than derived from the
+    /// `rename_all`, which is how `RightPanelTab::Scm` turned out to be
+    /// `"changes"` — a rename someone tidying the enum would otherwise undo
+    /// without noticing.
+    #[test]
+    fn every_enum_setting_keeps_the_spelling_it_has_on_disk() {
+        fn spelled<T: serde::Serialize>(value: T) -> String {
+            serde_json::to_value(value)
+                .expect("a setting serializes")
+                .as_str()
+                .expect("an enum setting is a string")
+                .to_string()
+        }
+        macro_rules! pin {
+            ($ty:ty, $($v:ident => $s:literal),+ $(,)?) => {{
+                $(
+                    assert_eq!(
+                        spelled(<$ty>::$v),
+                        $s,
+                        "{}::{} is written {:?} in every config.json already on \
+                         disk; changing it forgets the setting silently",
+                        stringify!($ty),
+                        stringify!($v),
+                        $s
+                    );
+                    assert_eq!(
+                        serde_json::from_value::<$ty>(serde_json::json!($s)).expect("reads back"),
+                        <$ty>::$v,
+                        "{}::{} does not read back from {:?}",
+                        stringify!($ty),
+                        stringify!($v),
+                        $s
+                    );
+                )+
+            }};
+        }
+
+        pin!(WdStrategy, Inherit => "inherit", Home => "home", Custom => "custom");
+        pin!(StartupMode, Normal => "normal", Maximized => "maximized", Fullscreen => "fullscreen");
+        pin!(CursorStyle, Block => "block", Bar => "bar", Underline => "underline");
+        pin!(NewTabPosition, AfterCurrent => "after-current", End => "end");
+        pin!(TabBarPosition, Top => "top", Left => "left");
+        pin!(
+            WindowBackdrop,
+            Auto => "auto", Blur => "blur", Mica => "mica",
+            MicaAlt => "mica-alt", Acrylic => "acrylic", Off => "off",
+        );
+        pin!(
+            SidebarGrouping,
+            Repo => "repo", RepoOrDirectory => "repo-or-directory", None => "none",
+        );
+        pin!(NotifyMode, Never => "never", Unfocused => "unfocused", Always => "always");
+        pin!(UpdateChannel, Stable => "stable", Nightly => "nightly");
+        pin!(
+            MouseZoomModifier,
+            Platform => "platform", Ctrl => "ctrl", Alt => "alt", None => "none",
+        );
+        pin!(BellMode, None => "none", Visual => "visual", Audible => "audible", Both => "both");
+        // Not "scm": the tab is called Changes on screen and the setting has
+        // always said so.
+        pin!(RightPanelTab, Info => "info", Scm => "changes", Files => "files");
+        pin!(LinkFileOpen, Internal => "internal", System => "system", Command => "command");
+        pin!(DiffViewMode, Split => "split", Unified => "unified");
+        pin!(DocumentLayout, Dock => "dock", Fill => "fill");
+    }
 }