improvise-9trl: pin the remove-formula refusal and its exit code

A script that removes a formula that is not there now refuses and exits 1,
where it used to exit 0. The None arm had no test, so reverting it to a silent
no-op left the suite green.

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

context/code/cli.md

@@ -319,3 +319,13 @@ are listed in improvise-i3o5. `q` on a dirty document is deliberately left a
 report: headless, its text is false — the CLI saves anyway (improvise-ep5o).
 The two rivals udt2 named both stay green: a successful `:w` and a successful
 `fit-measure` report through `set_status` and exit 0.
+
+**`remove-formula` of a formula that is not there now exits 1** (improvise-tej1,
+improvise-9trl). It used to exit 0: the effect was keyed by names and removing
+nothing was a silent no-op. Since tej1, `RemoveFormula` names its formula by
+`FormulaId`, and `remove-formula <category> <target>` resolves the two names
+to an id in `execute`. When nothing matches it `refuse`s with `No formula for
+<target> in <category>`, so a script that removes a formula it never added now
+fails where it used to pass. That is the §10 rule applied: nothing changed, so
+the request was not met. `remove_formula_of_a_missing_formula_is_a_refusal`
+pins it, with a present formula as the control.

context/test-evidence/command.md

@@ -6008,3 +6008,13 @@ from the landed cell and untouched.
 flag. This test fails alone. Every other test stays green, which was the gap.
 Once improvise-fy9o re-seeds the reopened editor, a stale `touched` would make
 every untouched Tab or Enter write its seed.
+
+### remove_formula_of_a_missing_formula_is_a_refusal
+
+improvise-9trl, from the review of #223. The script command's `None` arm refuses,
+which is what makes `main.rs` exit 1, and nothing tested it. Rival: `None =>
+vec![]`, the silent no-op the command had before. With it, the whole suite
+stayed green, and this test now fails on `last_batch_refused`. The control
+arm, a formula that is present, must not refuse and must remove it, so a
+command that refused every call cannot pass.
+

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

@@ -67,6 +67,34 @@ mod tests {
         assert_eq!(view.categories_on(Axis::Column), vec!["Type", "Month"]);
     }
 
+    /// improvise-9trl: a script naming a formula that is not there is refused,
+    /// so `main.rs` exits 1. It was a silent no-op that exited 0.
+    #[test]
+    fn remove_formula_of_a_missing_formula_is_a_refusal() {
+        let mut m = two_cat_model();
+        let tax = crate::formula::parse_formula("Tax = Food * 0.1", "Type").unwrap();
+        m.model.add_formula(tax);
+        let layout = make_layout(&m);
+        let reg = make_registry();
+        let ctx = make_ctx(&m, &layout, &reg);
+        let run = |args: [&str; 2]| {
+            let args = args.iter().map(|s| s.to_string()).collect();
+            let mut app = crate::ui::app::App::new(m.clone(), None);
+            app.apply_effects(RemoveFormulaCmd(args).execute(&ctx));
+            app
+        };
+        let missing = run(["Type", "Profit"]);
+        assert!(
+            missing.last_batch_refused(),
+            "{}",
+            missing.view_state.status_msg
+        );
+        assert_eq!(missing.model_state.workbook.model.formulas().len(), 1);
+        let present = run(["Type", "Tax"]);
+        assert!(!present.last_batch_refused(), "the control must not refuse");
+        assert!(present.model_state.workbook.model.formulas().is_empty());
+    }
+
     #[test]
     fn write_cmd_without_args_saves() {
         let m = two_cat_model();