y1av: seat the at-cursor tests off index 0

delete-formula-at-cursor, switch-view-at-cursor and delete-view-at-cursor
were asserted with the cursor at 0 of a one-element list, where the item
under the cursor and the first item are one item. A DeleteFormulaAtCursor
hard-wired to index 0 passed the whole workspace. Now each cursor sits at
index 1 of a longer list; the index-0 rivals fail.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

context/test-evidence/command.md

@@ -4721,17 +4721,38 @@ are now named, so moving the right cursor on the wrong panel fails.
 
 ### delete_formula_at_cursor_with_formulas
 
-Asserts the `RemoveFormula` names `Profit` in `Type` — the formula the cursor is
+Asserts the `RemoveFormula` names the formula the cursor is on, rather than merely
-on — rather than merely that a formula was removed.
+that a formula was removed. PR #148 named the field, but its fixture was **one**
+formula with the cursor at **0**, where "the formula under the cursor" and "the
+first formula" are the same formula (improvise-y1av). The rival it could not see —
+`DeleteFormulaAtCursor` reading index `0` instead of `ctx.formula_cursor` — passed
+the **whole workspace**, so `d` in the formula panel deleting the wrong formula had
+no guard anywhere. Now two formulas, cursor at **1**: it must remove `Tax` and must
+not name `Profit`. Rival `let cursor = 0usize.min(..)` injected, full suite run:
+this is the only test that fails.
 
 ### switch_view_at_cursor_with_valid_cursor
 
-Names `Default`, the view under the cursor.
+Names the view under the cursor. Same fixture defect as above (improvise-y1av):
+`two_cat_model` has one view, so the cursor at 0 named `Default` whether or not
+the command read it. Now `Default, Other` with the cursor at **1**, asserting
+`Other`. Rival `get(cursor).and(first())` — in bounds only, so the out-of-bounds
+arm is unchanged and `switch_view_at_cursor_out_of_bounds_returns_empty` cannot be
+what catches it — injected and run: fails here, in
+`delete_view_at_cursor_deletes_the_view_under_a_nonzero_cursor`, and in the two
+`wasm-client/tests/lockstep.rs` tests that were previously the only guard.
+
+### delete_view_at_cursor_deletes_the_view_under_a_nonzero_cursor
+
+improvise-y1av. `Default, Other, Third` with the cursor at **1**: deletes `Other`
+and steps the panel cursor back to 0. The same rival as above fails it.
 
 ### delete_view_at_cursor_zero_does_not_adjust_cursor
 
 Names `Default` too. Its existing negative half — no `SetPanelCursor` at
-position 0 — is unchanged.
+position 0 — is unchanged. Position 0 is this test's subject, so it cannot
+separate "the view under the cursor" from "the first view" and does not try to;
+the test above does.
 
 ### commit_category_add_with_name_produces_add_effect
 

crates/improvise-command/src/command/cmd/panel.rs

@@ -395,39 +395,50 @@ mod tests {
         assert!(effects.is_empty());
     }
 
+    /// Evidence: `context/test-evidence/command.md`.
     #[test]
     fn delete_formula_at_cursor_with_formulas() {
         let mut m = two_cat_model();
-        m.model.add_formula(crate::formula::ast::Formula {
+        for (target, raw) in [("Profit", "Profit = 1"), ("Tax", "Tax = 2")] {
-            raw: "Profit = Revenue - Cost".to_string(),
+            m.model.add_formula(crate::formula::ast::Formula {
-            target: "Profit".to_string(),
+                raw: raw.to_string(),
-            target_category: "Type".to_string(),
+                target: target.to_string(),
-            expr: crate::formula::ast::Expr::Number(0.0),
+                target_category: "Type".to_string(),
-            filter: None,
+                expr: crate::formula::ast::Expr::Number(0.0),
-            format: None,
+                filter: None,
-        });
+                format: None,
+            });
+        }
         let layout = make_layout(&m);
         let reg = make_registry();
-        let ctx = make_ctx(&m, &layout, &reg);
+        let mut ctx = make_ctx(&m, &layout, &reg);
+        ctx.formula_cursor = 1;
         let effects = DeleteFormulaAtCursor.execute(&ctx);
         let dbg = effects_debug(&effects);
         assert!(
-            dbg.contains("RemoveFormula { target: \"Profit\", target_category: \"Type\" }"),
+            dbg.contains("RemoveFormula { target: \"Tax\", target_category: \"Type\" }"),
-            "must remove the formula AT THE CURSOR, got: {dbg}"
+            "must remove the formula AT THE CURSOR (Tax, index 1), got: {dbg}"
+        );
+        assert!(
+            !dbg.contains("\"Profit\""),
+            "removed the first formula, not the one under the cursor: {dbg}"
         );
     }
 
+    /// Evidence: `context/test-evidence/command.md`.
     #[test]
     fn switch_view_at_cursor_with_valid_cursor() {
-        let m = two_cat_model();
+        let mut m = two_cat_model();
+        m.create_view("Other");
         let layout = make_layout(&m);
         let reg = make_registry();
-        let ctx = make_ctx(&m, &layout, &reg);
+        let mut ctx = make_ctx(&m, &layout, &reg);
+        ctx.view_panel_cursor = 1;
         let effects = SwitchViewAtCursor.execute(&ctx);
         let dbg = effects_debug(&effects);
         assert!(
-            dbg.contains("SwitchView(\"Default\")"),
+            dbg.contains("SwitchView(\"Other\")"),
-            "must switch to the view UNDER THE CURSOR, got: {dbg}"
+            "must switch to the view UNDER THE CURSOR (Other, index 1), got: {dbg}"
         );
         assert!(dbg.contains("Normal"), "Expected Normal mode, got: {dbg}");
     }
@@ -504,6 +515,27 @@ mod tests {
         );
     }
 
+    /// Evidence: `context/test-evidence/command.md`.
+    #[test]
+    fn delete_view_at_cursor_deletes_the_view_under_a_nonzero_cursor() {
+        let mut m = two_cat_model();
+        m.create_view("Other");
+        m.create_view("Third");
+        let layout = make_layout(&m);
+        let reg = make_registry();
+        let mut ctx = make_ctx(&m, &layout, &reg);
+        ctx.view_panel_cursor = 1;
+        let dbg = effects_debug(&DeleteViewAtCursor.execute(&ctx));
+        assert!(
+            dbg.contains("DeleteView(\"Other\")"),
+            "must delete the view UNDER THE CURSOR (Other, index 1), got: {dbg}"
+        );
+        assert!(
+            dbg.contains("SetPanelCursor { panel: View, cursor: 0 }"),
+            "a delete off position 0 steps the cursor back, got: {dbg}"
+        );
+    }
+
     #[test]
     fn delete_view_at_cursor_zero_does_not_adjust_cursor() {
         let m = two_cat_model();