Allow regex in / search (#627)

* Allow regex in / search

* Handle invalid regexen

* Update constructor

* Escape backslash

* Also support backwards search

Author: Aiden Scandella

src/actions/actions.ts

@@ -782,7 +782,7 @@ export class CommandSearchForwards extends BaseCommand {
   isMotion = true;
 
   public async exec(position: Position, vimState: VimState): Promise<VimState> {
-    vimState.searchState = new SearchState(SearchDirection.Forward, vimState.cursorPosition);
+    vimState.searchState = new SearchState(SearchDirection.Forward, vimState.cursorPosition, "", { isRegex: true });
     vimState.currentMode = ModeName.SearchInProgressMode;
 
     return vimState;
@@ -796,7 +796,7 @@ export class CommandSearchBackwards extends BaseCommand {
   isMotion = true;
 
   public async exec(position: Position, vimState: VimState): Promise<VimState> {
-    vimState.searchState = new SearchState(SearchDirection.Backward, vimState.cursorPosition);
+    vimState.searchState = new SearchState(SearchDirection.Backward, vimState.cursorPosition, "", { isRegex: true });
     vimState.currentMode = ModeName.SearchInProgressMode;
 
     return vimState;

src/mode/modeHandler.ts

@@ -180,6 +180,7 @@ export class SearchState {
 
   private _matchesDocVersion: number;
   private _searchDirection: SearchDirection = SearchDirection.Forward;
+  private isRegex: boolean;
 
   private _searchString = "";
   public get searchString(): string {
@@ -214,7 +215,21 @@ export class SearchState {
         ignorecase = false;
       }
 
-      const regex = new RegExp(search.replace(SearchState.specialCharactersRegex, "\\$&"), ignorecase ? 'gi' : 'g');
+      let searchRE = search;
+      if (!this.isRegex) {
+        searchRE = search.replace(SearchState.specialCharactersRegex, "\\$&");
+      }
+
+      const regexFlags = ignorecase ? 'gi' : 'g';
+
+      let regex: RegExp;
+      try {
+        regex = new RegExp(searchRE, regexFlags);
+      } catch (err) {
+        // Couldn't compile the regexp, try again with special characters escaped
+        searchRE = search.replace(SearchState.specialCharactersRegex, "\\$&");
+        regex = new RegExp(searchRE, regexFlags);
+      }
 
       outer:
       for (let lineIdx = 0; lineIdx < TextEditor.getLineCount(); lineIdx++) {
@@ -228,7 +243,7 @@ export class SearchState {
 
           this.matchRanges.push(new vscode.Range(
             new Position(lineIdx, result.index),
-            new Position(lineIdx, result.index + search.length)
+            new Position(lineIdx, result.index + result[0].length)
           ));
 
           if (result.index === regex.lastIndex) {
@@ -281,10 +296,11 @@ export class SearchState {
     }
   }
 
-  constructor(direction: SearchDirection, startPosition: Position, searchString = "") {
+  constructor(direction: SearchDirection, startPosition: Position, searchString = "", { isRegex = false } = {}) {
     this._searchDirection = direction;
     this._searchCursorStartPosition = startPosition;
     this.searchString = searchString;
+    this.isRegex = isRegex;
   }
 }
 

test/mode/modeNormal.test.ts

@@ -1191,6 +1191,13 @@ suite("Mode Normal", () => {
       end: ["|one", "twooo", "thurr"]
     });
 
+    newTest({
+      title: "/ can search with regex",
+      start: ["|", "one two2o"],
+      keysPressed: "/o\\do",
+      end: ["", "one tw|o2o"]
+    });
+
     newTest({
       title: "Can do C",
       start: ["export const options = {", "|", "};"],