fixes #657 implements search history (#1147)

* fixes #657 implements search history

* Added history config option to limit amount of search history remembered. This can be used when command history is implemented as well

package.json

@@ -352,6 +352,11 @@
           "description": "Show where a / search matches as you type it.",
           "default": true
         },
+        "vim.history": {
+          "type": "number",
+          "description": "How much search or command history should be remembered",
+          "default": 50
+        },
         "vim.autoindent": {
           "type": "boolean",
           "description": "Indent code automatically.",

src/actions/actions.ts

@@ -1414,7 +1414,9 @@ class RightArrowInInsertMode extends ArrowsInInsertMode {
 @RegisterAction
 class CommandInsertInSearchMode extends BaseCommand {
   modes = [ModeName.SearchInProgressMode];
-  keys = ["<character>"];
+  keys = [["<character>"],
+  ["<up>"],
+  ["<down>"]];
   runsOnceForEveryCursor() { return this.keysPressed[0] === '\n'; }
 
   public async exec(position: Position, vimState: VimState): Promise<VimState> {
@@ -1429,22 +1431,57 @@ class CommandInsertInSearchMode extends BaseCommand {
 
       // Repeat the previous search if no new string is entered
       if (searchState.searchString === "") {
-        const prevSearch = vimState.searchStatePrevious!;
-        if (prevSearch) {
-          searchState.searchString = prevSearch.searchString;
+        const prevSearchList = vimState.searchStatePrevious!;
+        if (prevSearchList.length > 0) {
+          searchState.searchString = prevSearchList[prevSearchList.length - 1].searchString;
         }
       }
-      // Store this search
-      vimState.searchStatePrevious = searchState;
+
+      // Store this search if different than previous
+      if (vimState.searchStatePrevious.length !== 0) {
+        if (searchState.searchString !== vimState.searchStatePrevious[vimState.searchStatePrevious.length - 1]!.searchString) {
+          vimState.searchStatePrevious.push(searchState);
+        }
+      } else {
+        vimState.searchStatePrevious.push(searchState);
+      }
+
+      // Make sure search history does not exceed configuration option
+      if (vimState.searchStatePrevious.length > Configuration.history) {
+        vimState.searchStatePrevious.splice(0, 1);
+      }
+
+      // Update the index to the end of the search history
+      vimState.searchStateIndex = vimState.searchStatePrevious.length - 1;
 
       // Move cursor to next match
       vimState.cursorPosition = searchState.getNextSearchMatchPosition(vimState.cursorPosition).pos;
 
       return vimState;
+    } else if (key === "<up>") {
+      const prevSearchList = vimState.searchStatePrevious!;
+      if (prevSearchList[vimState.searchStateIndex] !== undefined) {
+        searchState.searchString = prevSearchList[vimState.searchStateIndex].searchString;
+        vimState.searchStateIndex -= 1;
+      }
+    } else if (key === "<down>") {
+      const prevSearchList = vimState.searchStatePrevious!;
+      if (prevSearchList[vimState.searchStateIndex] !== undefined) {
+        searchState.searchString = prevSearchList[vimState.searchStateIndex].searchString;
+        vimState.searchStateIndex += 1;
+      }
     } else {
       searchState.searchString += this.keysPressed[0];
     }
 
+    // Clamp the history index to stay within bounds of search history length
+    if (vimState.searchStateIndex > vimState.searchStatePrevious.length - 1) {
+      vimState.searchStateIndex = vimState.searchStatePrevious.length - 1;
+    }
+    if (vimState.searchStateIndex < 0) {
+      vimState.searchStateIndex = 0;
+    }
+
     return vimState;
   }
 }
@@ -1667,6 +1704,9 @@ export class CommandSearchForwards extends BaseCommand {
     vimState.searchState = new SearchState(SearchDirection.Forward, vimState.cursorPosition, "", { isRegex: true });
     vimState.currentMode = ModeName.SearchInProgressMode;
 
+    // Reset search history index
+    vimState.searchStateIndex = vimState.searchStatePrevious.length - 1;
+
     Configuration.hl = true;
 
     return vimState;
@@ -1683,6 +1723,9 @@ export class CommandSearchBackwards extends BaseCommand {
     vimState.searchState = new SearchState(SearchDirection.Backward, vimState.cursorPosition, "", { isRegex: true });
     vimState.currentMode = ModeName.SearchInProgressMode;
 
+    // Reset search history index
+    vimState.searchStateIndex = vimState.searchStatePrevious.length - 1;
+
     Configuration.hl = true;
 
     return vimState;

src/configuration/configuration.ts

@@ -121,6 +121,11 @@ class ConfigurationClass {
    */
   leader = "\\";
 
+  /**
+   * How much search or command history should be remembered
+   */
+  history = 50;
+
   /**
    * Show results of / or ? search as user is typing?
    */

src/mode/modeHandler.ts

@@ -170,7 +170,15 @@ export class VimState {
 
   public searchState: SearchState | undefined = undefined;
 
-  public searchStatePrevious: SearchState | undefined = undefined;
+  /**
+   *  Index used for navigating search history with <up> and <down> when searching
+   */
+  public searchStateIndex: number = 0;
+
+  /**
+   * Previous searches performed
+   */
+  public searchStatePrevious: SearchState[] = [];
 
   public isRecordingMacro: boolean = false;