add tests for search feature

tests/search.rs

@@ -0,0 +1,83 @@
+#![cfg(feature = "search")]
+
+use tui_textarea::{CursorMove, TextArea};
+
+#[test]
+fn search_forward() {
+    #[rustfmt::skip]
+    let mut textarea = TextArea::from([
+        "fooo foo",
+        "foo fo foo fooo",
+        "foooo",
+    ]);
+
+    // Move to 'f' on 'fo' at line 2
+    textarea.move_cursor(CursorMove::Jump(1, 4));
+
+    textarea.set_search_pattern("fo+").unwrap();
+
+    let expected = [(1, 7), (1, 11), (2, 0), (0, 0), (0, 5), (1, 0), (1, 4)];
+    for (i, pos) in expected.into_iter().enumerate() {
+        let moved = textarea.search_forward(false);
+        let cursor = textarea.cursor();
+        assert!(moved, "{}th move didn't happen: {:?}", i, cursor);
+        assert_eq!(pos, cursor, "{}th move is unexpected", i);
+    }
+}
+
+#[test]
+fn search_backward() {
+    #[rustfmt::skip]
+    let mut textarea = TextArea::from([
+        "fooo foo",
+        "foo fo foo fooo",
+        "foooo",
+    ]);
+
+    // Move to 'f' on 'fo' at line 2
+    textarea.move_cursor(CursorMove::Jump(1, 4));
+
+    textarea.set_search_pattern("fo+").unwrap();
+
+    let expected = [(1, 0), (0, 5), (0, 0), (2, 0), (1, 11), (1, 7), (1, 4)];
+    for (i, pos) in expected.into_iter().enumerate() {
+        let moved = textarea.search_back(false);
+        let cursor = textarea.cursor();
+        assert!(moved, "{}th move didn't happen: {:?}", i, cursor);
+        assert_eq!(pos, cursor, "{}th move is unexpected", i);
+    }
+}
+
+#[test]
+fn search_not_found() {
+    let mut textarea = TextArea::from(["fo fo fo fo"]);
+    textarea.set_search_pattern("foo+").unwrap();
+
+    assert!(!textarea.search_forward(false));
+    assert!(!textarea.search_back(false));
+}
+
+#[test]
+fn accept_cursor_position() {
+    let mut textarea = TextArea::from(["foooo fooooooo"]);
+    textarea.set_search_pattern("foo+").unwrap();
+
+    let cursor = textarea.cursor();
+    assert!(textarea.search_forward(true));
+    assert_eq!(textarea.cursor(), cursor);
+    assert!(textarea.search_back(true));
+    assert_eq!(textarea.cursor(), cursor);
+}
+
+#[test]
+fn set_search_pattern() {
+    let mut textarea = TextArea::default();
+
+    assert!(textarea.search_pattern().is_none());
+    textarea.set_search_pattern("(foo").unwrap_err();
+    assert!(textarea.search_pattern().is_none());
+
+    textarea.set_search_pattern("(fo+)ba+r").unwrap();
+    let pat = textarea.search_pattern().unwrap();
+    assert_eq!(pat.as_str(), "(fo+)ba+r");
+}