Fix frontmatter property spaces

apps/desktop/src/features/editor/Editor.test.tsx

@@ -416,6 +416,41 @@ describe("Editor", () => {
         expect(screen.getAllByDisplayValue("Updated title")).toHaveLength(2);
     });
 
+    it("allows inserting spaces while editing text properties", async () => {
+        setEditorTabs([
+            {
+                id: "tab-1",
+                noteId: "notes/current",
+                title: "Frontmatter title",
+                content: "---\ntitle: Frontmatter title\n---\nBody",
+            },
+        ]);
+
+        renderComponent(<Editor />);
+
+        await act(async () => {
+            fireEvent.click(screen.getByRole("button", { name: "Properties" }));
+        });
+
+        const view = getEditorView();
+        const propertyInput = screen.getAllByDisplayValue(
+            "Frontmatter title",
+        )[1];
+
+        await act(async () => {
+            fireEvent.change(propertyInput, {
+                target: { value: "Frontmatter title " },
+            });
+        });
+
+        expect((propertyInput as HTMLInputElement).value).toBe(
+            "Frontmatter title ",
+        );
+        expect(view.state.doc.toString()).toContain(
+            'title: "Frontmatter title "',
+        );
+    });
+
     it("does not underline markdown headings in source mode", async () => {
         setEditorTabs([
             {

apps/desktop/src/features/editor/FrontmatterPanel.helpers.test.ts

@@ -38,4 +38,18 @@ tags:
 ---
 `);
     });
+
+    it("preserves a trailing space while text properties are being edited", () => {
+        const raw = serializeFrontmatterRaw([
+            { key: "title", value: "Roadmap " },
+        ]);
+
+        expect(raw).toBe(`---
+title: "Roadmap "
+---
+`);
+        expect(parseFrontmatterRaw(raw ?? "")).toEqual([
+            { key: "title", value: "Roadmap " },
+        ]);
+    });
 });

apps/desktop/src/features/editor/FrontmatterPanel.tsx

@@ -78,14 +78,15 @@ export function serializeFrontmatterRaw(
             key: key.trim(),
             value: Array.isArray(value)
                 ? value.map((item) => item.trim()).filter(Boolean)
-                : typeof value === "string"
-                  ? value.trim()
-                  : value,
+                : value,
         }))
         .filter(({ key, value }) => {
             if (!key) return false;
             if (Array.isArray(value)) return value.length > 0;
-            return value !== null && value !== "";
+            return (
+                value !== null &&
+                (typeof value !== "string" || value.trim() !== "")
+            );
         });
 
     if (!cleaned.length) return null;
@@ -104,7 +105,12 @@ export function serializeFrontmatterRaw(
 
 function quoteYaml(value: string): string {
     if (!value) return '""';
-    if (/^[A-Za-z0-9 _./:@#%+,-]+$/.test(value)) return value;
+    if (
+        value.trim() === value &&
+        /^[A-Za-z0-9 _./:@#%+,-]+$/.test(value)
+    ) {
+        return value;
+    }
     return JSON.stringify(value);
 }