Escaping special regex chars (Azure#844)

* Escaping special regex chars

* Separating test function into its own file

* Uncommenting line

* Added functionality to prevent double escaping and made testing function more debug friendly

---------

Co-authored-by: Reinier Cruz <[email protected]>

src/panels/TcpDumpPanel.ts

@@ -24,7 +24,16 @@ const tcpDumpCommandBase = "tcpdump --snapshot-length=0 -vvv";
 const captureDir = "/tmp";
 const captureFilePrefix = "vscodenodecap_";
 const captureFileBasePath = `${captureDir}/${captureFilePrefix}`;
-const captureFilePathRegex = `${captureFileBasePath.replace(/\//g, "\\$&")}(.*)\\.cap`; // Matches the part of the filename after the prefix
+const captureFileBasePathEscaped = escapeRegExp(captureFileBasePath);
+const captureFilePathRegex = `${captureFileBasePathEscaped}(.*)\\.cap`; // Matches the part of the filename after the prefix
+
+// Escape all regex meta characters to ensure sanitation and '/' for later use in regex pattern
+export function escapeRegExp(input: string): string {
+    return input.replace(/(\\)?([.*+?^${}()|[\]\\/])/g, (match, backslash, char) => {
+        // If there's a backslash before the character, return the match unchanged. (To prevent double escaping)
+        return backslash ? match : `\\${char}`;
+    });
+} //Reference for regex syntax chars: https://262.ecma-international.org/13.0/index.html#prod-SyntaxCharacter
 
 function getPodName(node: NodeName) {
     return `debug-${node}`;

src/tests/suite/TcpDumpPanel.test.ts

@@ -0,0 +1,32 @@
+import * as assert from "assert";
+import { escapeRegExp } from "../../panels/TcpDumpPanel";
+
+describe("testEscapeRegExp", () => {
+    it("should escape special regex characters", () => {
+        const input = "a.b*c?d+e^f$g|h(i)j{k}l[m]n\\o";
+        const expected = "a\\.b\\*c\\?d\\+e\\^f\\$g\\|h\\(i\\)j\\{k\\}l\\[m\\]n\\\\o";
+        const escapedInput = escapeRegExp(input);
+        assert.equal(escapedInput, expected);
+    });
+
+    it("should not double escape already escaped characters", () => {
+        const input = "a\\.b\\*c\\?d\\+e\\^f\\$g\\|h\\(i\\)j\\{k\\}l\\[m\\]n\\\\o";
+        const expected = "a\\.b\\*c\\?d\\+e\\^f\\$g\\|h\\(i\\)j\\{k\\}l\\[m\\]n\\\\o";
+        const escapedInput = escapeRegExp(input);
+        assert.equal(escapedInput, expected);
+    });
+
+    it("should return an empty string if input is empty", () => {
+        const input = "";
+        const expected = "";
+        const escapedInput = escapeRegExp(input);
+        assert.equal(escapedInput, expected);
+    });
+
+    it("should return the same string if no special characters", () => {
+        const input = "abcdefg";
+        const expected = "abcdefg";
+        const escapedInput = escapeRegExp(input);
+        assert.equal(escapedInput, expected);
+    });
+});