UPDATE: Dump of initial files

base/src/test/test_model_is_empty_cell.rs

@@ -0,0 +1,55 @@
+#![allow(clippy::unwrap_used)]
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_is_empty_cell_non_existing_sheet() {
+    let model = new_empty_model();
+    assert_eq!(
+        model.is_empty_cell(13, 1, 1),
+        Err("Invalid sheet index".to_string())
+    );
+}
+
+#[test]
+fn test_is_empty_cell() {
+    let mut model = new_empty_model();
+    assert!(model.is_empty_cell(0, 3, 1).unwrap());
+    model.set_user_input(0, 3, 1, "Hello World".to_string());
+    assert!(!model.is_empty_cell(0, 3, 1).unwrap());
+    model.set_cell_empty(0, 3, 1).unwrap();
+    assert!(model.is_empty_cell(0, 3, 1).unwrap());
+}
+
+#[test]
+fn test_is_empty_cell_unset_cell() {
+    let model = new_empty_model();
+    assert_eq!(model.is_empty_cell(0, 1, 1), Ok(true));
+}
+
+#[test]
+fn test_is_empty_cell_with_value() {
+    let mut model = new_empty_model();
+    model._set("A1", "hello");
+    assert_eq!(model.is_empty_cell(0, 1, 1), Ok(false));
+}
+
+#[test]
+fn test_is_empty_cell_empty_string_not_empty() {
+    let mut model = new_empty_model();
+    model._set("A1", "");
+    assert_eq!(model.is_empty_cell(0, 1, 1), Ok(false));
+}
+
+#[test]
+fn test_is_empty_cell_formula_that_evaluates_to_empty_string() {
+    let mut model = new_empty_model();
+    model._set("A1", "=A2");
+    assert_eq!(model.is_empty_cell(0, 1, 1), Ok(false));
+}
+
+#[test]
+fn test_is_empty_cell_formula_that_evaluates_to_zero() {
+    let mut model = new_empty_model();
+    model._set("A1", "=2*A2");
+    assert_eq!(model.is_empty_cell(0, 1, 1), Ok(false));
+}