From a78186cb9644e985219a445f6db96925863c6b9c Mon Sep 17 00:00:00 2001
From: Michele Riva <ciao@micheleriva.it>
Date: Mon, 22 Jan 2024 16:52:20 +0100
Subject: [PATCH] fix: fixes crash when highlighting strings with special
 characters

---
 src/index.test.ts | 12 ++++++++++++
 src/index.ts      |  6 +++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/index.test.ts b/src/index.test.ts
index 6afcf53..5dfa6b6 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -131,3 +131,15 @@ describe('trim method', () => {
     assert.strictEqual(highlighter.highlight(text, 'the').trim(5, false), '<mark class="orama-highlight">The</mark> q')
   })
 })
+
+describe('special characters', () => {
+  it('should correctly highlight a text with special characters', () => {
+    const text = 'C++ is a hell of a language'
+    const searchTerm = 'C++'
+    const expectedResult = '<mark class="orama-highlight">C++</mark> is a hell of a language'
+
+    const highlighter = new Highlight()
+
+    assert.strictEqual(highlighter.highlight(text, searchTerm).HTML, expectedResult)
+  })
+})
\ No newline at end of file
diff --git a/src/index.ts b/src/index.ts
index cf1eb1d..eda5413 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -36,7 +36,7 @@ export class Highlight {
     const CSSClass = this.options.CSSClass ?? defaultOptions.CSSClass
     const regexFlags = caseSensitive ? 'g' : 'gi'
     const boundary = wholeWords ? '\\b' : ''
-    const searchTerms = (caseSensitive ? searchTerm : searchTerm.toLowerCase()).trim().split(/\s+/).join('|')
+    const searchTerms = this.escapeRegExp(caseSensitive ? searchTerm : searchTerm.toLowerCase()).trim().split(/\s+/).join('|')
     const regex = new RegExp(`${boundary}${searchTerms}${boundary}`, regexFlags)
     const positions: Array<{ start: number, end: number }> = []
     const highlightedParts: string[] = []
@@ -91,4 +91,8 @@ export class Highlight {
   get HTML (): string {
     return this._HTML
   }
+
+  private escapeRegExp(string: string): string {
+    return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+  }
 }