fix(renderer): keep separators placed next to each other

src/utils/__tests__/renderer-separator-collapse.test.ts

@@ -92,6 +92,39 @@ describe('renderer separator collapse around empty widgets', () => {
         expect(out).toBe('A:C');
     });
 
+    it.each([
+        { label: 'two spaces', characters: [' ', ' '], expected: 'A  B' },
+        { label: 'two pipes', characters: ['|', '|'], expected: 'A |  | B' },
+        { label: 'a space then a pipe', characters: [' ', '|'], expected: 'A  | B' },
+        { label: 'a glyph between spaces', characters: [' ', '•', ' '], expected: 'A • B' }
+    ])('keeps separators placed next to each other between visible widgets: $label', ({ characters, expected }) => {
+        const separators = characters.map((character, i): WidgetItem => ({ id: `sep-${i}`, type: 'separator', character }));
+        const widgets = [T('a'), ...separators, T('b')];
+        const out = stripSgrCodes(render(widgets, { 0: 'A', [widgets.length - 1]: 'B' }));
+
+        expect(out).toBe(expected);
+    });
+
+    it('keeps a run of separators with a visible one as the boundary around an empty widget', () => {
+        const space1: WidgetItem = { id: 'space1', type: 'separator', character: ' ' };
+        const bullet: WidgetItem = { id: 'bullet', type: 'separator', character: '•' };
+        const space2: WidgetItem = { id: 'space2', type: 'separator', character: ' ' };
+        const pipe: WidgetItem = { id: 'pipe', type: 'separator', character: '|' };
+        const widgets = [T('a'), space1, bullet, space2, T('b'), pipe, T('c')];
+        const out = stripSgrCodes(render(widgets, { 0: 'A', 4: '', 6: 'C' }));
+        expect(out).toBe('A • C');
+    });
+
+    it('replaces a run of spacing before an empty widget with the whole run after it', () => {
+        const space1: WidgetItem = { id: 'space1', type: 'separator', character: ' ' };
+        const space2: WidgetItem = { id: 'space2', type: 'separator', character: ' ' };
+        const space3: WidgetItem = { id: 'space3', type: 'separator', character: ' ' };
+        const pipe: WidgetItem = { id: 'pipe', type: 'separator', character: '|' };
+        const widgets = [T('a'), space1, space2, T('b'), space3, pipe, T('c')];
+        const out = stripSgrCodes(render(widgets, { 0: 'A', 3: '', 6: 'C' }));
+        expect(out).toBe('A  | C');
+    });
+
     it('collapses multiple consecutive empty widgets into a single separator', () => {
         const widgets = [T('a'), SEP, T('b'), SEP, T('c'), SEP, T('d')];
         // both 'b' and 'c' render empty

src/utils/renderer.ts

@@ -1102,14 +1102,22 @@ export function renderStatusLine(
             // and the preceding visible content. A visible separator owns that
             // boundary, while spacing-only separators can be replaced by a
             // more meaningful separator that follows the empty widget.
+            // Separators placed next to each other form one run and all
+            // render; only a run on the far side of an empty widget can
+            // own or give up the boundary.
             let contentBeforeIndex: number | null = null;
             let replacesSpacingSeparator = false;
+            let followsSeparatorInRun = false;
             let crossedEmptyWidget = false;
             for (let j = i - 1; j >= 0; j--) {
                 const prevWidget = widgets[j];
                 if (!prevWidget)
                     continue;
                 if (prevWidget.type === 'separator') {
+                    if (!crossedEmptyWidget) {
+                        followsSeparatorInRun = true;
+                        continue;
+                    }
                     if (!isSpacingSeparator(prevWidget, settings.defaultSeparator))
                         break;
                     replacesSpacingSeparator = true;
@@ -1128,7 +1136,10 @@ export function renderStatusLine(
             if (contentBeforeIndex === null)
                 continue;
 
-            if (replacesSpacingSeparator) {
+            // Only the first separator of a run removes the spacing it
+            // replaces; the rest of the run would remove that run's own
+            // separators.
+            if (replacesSpacingSeparator && !followsSeparatorInRun) {
                 while (isSpacingSeparator(elements[elements.length - 1]?.widget, settings.defaultSeparator)) {
                     elements.pop();
                 }