begin adding tests for how searchList should be after a deletion

test/normal-delete-tests.sml

@@ -113,6 +113,116 @@ struct
            in
              Expect.isTrue (stringIsExpected andalso cursorIdxIsExpected)
            end)
+    , test "has same searchList when deleting after all matches" (fn _ =>
+        let
+          (* arrange *)
+          val originalIdx = 5
+          val originalString = "hello world\n"
+
+          val app = TestUtils.init originalString
+          val app = AppWith.idx (app, originalIdx)
+
+          val app = TestUtils.updateMany (app, "/he")
+          val app = AppUpdate.update (app, InputMsg.KEY_ENTER, Time.now ())
+
+          (* act *)
+          val newApp = TestUtils.updateMany (app, "dh")
+        in
+          (* assert *)
+          Expect.isTrue (#searchList app = #searchList newApp)
+        end)
+    , test "decrements search list by 1 when we delete a single char" (fn _ =>
+        let
+          (* arrange *)
+          val originalIdx = 1
+          val originalString = "hello world\n"
+
+          val app = TestUtils.init originalString
+          val app = AppWith.idx (app, originalIdx)
+
+          val app = TestUtils.updateMany (app, "/wo")
+          val app = AppUpdate.update (app, InputMsg.KEY_ENTER, Time.now ())
+
+          (* act *)
+          val newApp = TestUtils.updateMany (app, "dh")
+
+          (* assert *)
+          val oldSearchList = #searchList app
+          val oldSearchList = PersistentVector.toList oldSearchList
+
+          val expectedSearchList =
+            List.map
+              (fn {start, finish} => {start = start - 1, finish = finish - 1})
+              oldSearchList
+
+          val newSearchList = #searchList newApp
+          val newSearchList = PersistentVector.toList newSearchList
+        in
+          Expect.isTrue (newSearchList = expectedSearchList)
+        end)
+    , test "recognises new match when there is a match after deletion" (fn _ =>
+        let
+          (* arrange *)
+          val originalIdx = 6
+          val originalString = "hello world\n"
+
+          val app = TestUtils.init originalString
+          val app = AppWith.idx (app, originalIdx)
+
+          val app = TestUtils.updateMany (app, "/helloworld")
+          val app = AppUpdate.update (app, InputMsg.KEY_ENTER, Time.now ())
+
+          (* act *)
+          val newApp = TestUtils.updateMany (app, "dh")
+
+          (* assert *)
+          val expectedSearchList = [{start = 0, finish = 9}]
+
+          val newSearchList = #searchList newApp
+          val newSearchList = PersistentVector.toList newSearchList
+
+          val assertion =
+            PersistentVector.isEmpty (#searchList app)
+            andalso newSearchList = expectedSearchList
+        in
+          Expect.isTrue assertion
+        end)
+    , test
+        "extends existing match when existing match should extend \
+        \after deletion"
+        (fn _ =>
+           let
+             (* arrange *)
+             val originalIdx = 6
+             val originalString = "hello one\n"
+
+             val app = TestUtils.init originalString
+             val app = AppWith.idx (app, originalIdx)
+
+             val app = TestUtils.updateMany (app, "/o+")
+             val app = AppUpdate.update (app, InputMsg.KEY_ENTER, Time.now ())
+
+             (* act *)
+             val newApp = TestUtils.updateMany (app, "dh")
+
+             (* assert *)
+             val oldSearchList = #searchList app
+             val oldSearchList = PersistentVector.toList oldSearchList
+
+             val expectedOldSearchList =
+               [{start = 4, finish = 4}, {start = 6, finish = 6}]
+
+             val newSearchList = #searchList newApp
+             val newSearchList = PersistentVector.toList newSearchList
+
+             val expectedNewSearchList = [{start = 4, finish = 5}]
+
+             val assertion =
+               oldSearchList = expectedOldSearchList
+               andalso newSearchList = expectedNewSearchList
+           in
+             Expect.isTrue assertion
+           end)
     ]
 
   (* 'dl' motion and 'x' motion have identical behaviour *)