diff --git a/lib/shared/markdown.test.js b/lib/shared/markdown.test.js
index 8bec0b8f5..3d65813d7 100644
--- a/lib/shared/markdown.test.js
+++ b/lib/shared/markdown.test.js
@@ -1,88 +1,144 @@
 // @flow
 
 import { spoilerRegex } from './markdown.js';
+import { chatMentionRegex } from './mention-utils.js';
 
 // Each of the below tests is subject to the following RegEx pattern:
 // Spoiler RegEx: /^\|\|([^\n]+?)\|\|/g
 
 describe('spoilerRegex', () => {
   it('We expect a spoiler with a single space character to match.', () => {
     expect('|| ||').toMatch(spoilerRegex);
   });
 
   it('We expect a spoiler with regular text + spaces to match (1).', () => {
     expect('|| hello ||').toMatch(spoilerRegex);
   });
 
   it('We expect a spoiler with regular text + spaces to match (2).', () => {
     expect('||SPOILER||').toMatch(spoilerRegex);
   });
 
   it('We expect a spoiler containing any number of || within it to match (1).', () => {
     expect('|| || ||').toMatch(spoilerRegex);
   });
 
   it('We expect a spoiler containing any number of || within it to match (2).', () => {
     expect('||||||').toMatch(spoilerRegex);
   });
 
   it('We expect a spoiler containing any number of || within it, as well as regular text + spaces, to match.', () => {
     expect('||SPOILER||SPOILER||').toMatch(spoilerRegex);
   });
 
   it('We do not expect a spoiler containing a new line character to match (1).', () => {
     expect('||\n||').not.toMatch(spoilerRegex);
   });
 
   it('We do not expect a spoiler containing a new line character to match (2).', () => {
     expect('||\r\n||').not.toMatch(spoilerRegex);
   });
 
   it('We do not expect an empty spoiler to match.', () => {
     expect('||||').not.toMatch(spoilerRegex);
   });
 
   it('We expect a spoiler containing a single space to match, even when split across multiple lines.', () => {
     expect(
       '|| \
     ||',
     ).toMatch(spoilerRegex);
   });
 
   it('We do not expect a spoiler containing a new line character to match (3).', () => {
     expect(
       '|| \n\
     ||',
     ).not.toMatch(spoilerRegex);
   });
 
   it("We expect to extract 'hello' from the following spoiler: ||hello||", () => {
     const spoiler = '||hello||';
     const extracted = spoiler.match(spoilerRegex);
     expect(extracted ? extracted[0] : null).toMatch('hello');
   });
 
   it("We expect to extract '||' from the following spoiler: ||||||", () => {
     const spoiler = '||||||';
     const extracted = spoiler.match(spoilerRegex);
     expect(extracted ? extracted[0] : null).toMatch('||');
   });
 
   it("We expect to extract ' ' from the following spoiler: || || ||", () => {
     const spoiler = '|| || ||';
     const extracted = spoiler.match(spoilerRegex);
     expect(extracted ? extracted[0] : null).toMatch(' ');
   });
 
   it("We expect to extract '||THISISASPOILER||' from the following spoiler: ||||THISISASPOILER||||", () => {
     const spoiler = '||||THISISASPOILER||||';
     const extracted = spoiler.match(spoilerRegex);
     expect(extracted ? extracted[0] : null).toMatch('||THISISASPOILER||');
   });
 
   it("We expect to extract '' from the following spoiler: || \\|\\| ||", () => {
     const spoiler = '|| \\|\\| ||';
     const extracted = spoiler.match(spoilerRegex);
     expect(extracted ? extracted[0] : null).toMatch(' \\|\\| ');
   });
 });
+
+// Each of the below tests is subject to the following RegEx pattern:
+// Chat mention RegEx:
+// (?<!\\)(@\[\[(${idSchemaRegex}):(.{1,${chatNameMaxLength}?)(?<!\\)\]\])
+
+describe('chatMentionRegex', () => {
+  it('We do not expect an empty raw chat mention to match.', () => {
+    expect('@[[:]]').not.toMatch(chatMentionRegex);
+    expect('@[[]]').not.toMatch(chatMentionRegex);
+  });
+
+  it('We do not expect a raw chat mention with invalid id to match.', () => {
+    expect('@[[|:]]').not.toMatch(chatMentionRegex);
+    expect('@[[256|:hello]]').not.toMatch(chatMentionRegex);
+    expect('@[[foo:]]').not.toMatch(chatMentionRegex);
+    expect('@[[:bar]]').not.toMatch(chatMentionRegex);
+    expect('@[[|:bar]]').not.toMatch(chatMentionRegex);
+    expect('@[[foo:bar]]').not.toMatch(chatMentionRegex);
+  });
+
+  it('We do not expect to match raw chat mention with valid id and without text.', () => {
+    expect('@[[1:]]').not.toMatch(chatMentionRegex);
+    expect('@[[256|1:]]').not.toMatch(chatMentionRegex);
+  });
+
+  it('We do expect to match raw chat mention with valid id and text.', () => {
+    expect('@[[1:test]]').toMatch(chatMentionRegex);
+    expect('@[[256|1:test]]').toMatch(chatMentionRegex);
+  });
+
+  it('We do expect to properly match closed raw chat mention.', () => {
+    expect('@[[256|1:bar \\] \\]]]').toMatch(chatMentionRegex);
+  });
+
+  it('We do not expect to improperly match closed raw chat mention.', () => {
+    expect('@[[256|1:bar \\]]').not.toMatch(chatMentionRegex);
+    expect('@[[256|1:bar \\] \\]]').not.toMatch(chatMentionRegex);
+    expect('@[[256|1:bar] ]').not.toMatch(chatMentionRegex);
+  });
+
+  it('We do not expect to match raw chat mention with escaped @ char.', () => {
+    expect('\\@[[1:bar]]').not.toMatch(chatMentionRegex);
+  });
+
+  it('We do expect to match raw chat mention with escaped chars in default text field.', () => {
+    expect('@[[256|1:\\@\\[\\[1:test\\]\\] ]]').toMatch(chatMentionRegex);
+  });
+
+  it('We do not expect an invalid raw chat mention format to match.', () => {
+    expect('@[256|1:test]').not.toMatch(chatMentionRegex);
+    expect('@test').not.toMatch(chatMentionRegex);
+    expect('@[256|1:test]]').not.toMatch(chatMentionRegex);
+    expect('@[[256|1:test]').not.toMatch(chatMentionRegex);
+  });
+});