Swift: add a test case showing case canonicalization

Author: AlexDenisov

swift/extractor/infra/Path.cpp

@@ -17,8 +17,6 @@ static bool shouldCanonicalize() {
 }
 
 std::filesystem::path getCodeQLPath(std::string_view path) {
-  // TODO: this needs more testing
-  // TODO: check canonicalization of names on a case insensitive filesystems
   std::error_code ec;
   std::filesystem::path ret = {};
   static const auto canonicalize = shouldCanonicalize();

swift/integration-tests/osx-only/canonical-case/Files.expected

@@ -0,0 +1,2 @@
+| MiXeDcAsE.swifT:0:0:0:0 | MiXeDcAsE.swifT |
+| file://:0:0:0:0 |  |

swift/integration-tests/osx-only/canonical-case/Files.ql

@@ -0,0 +1,4 @@
+import swift
+
+from File f
+select f

swift/integration-tests/osx-only/canonical-case/MiXeDcAsE.swifT

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+SDK="-sdk $(xcrun -show-sdk-path)"
+FRONTEND="$(xcrun -find swift-frontend)"
+
+# This test case will only work on a case-insensitive FS (which is the default)
+$FRONTEND -frontend -c MIXEDCASE.swift $SDK

swift/integration-tests/osx-only/canonical-case/build.sh

@@ -0,0 +1,5 @@
+from create_database_utils import *
+
+run_codeql_database_create([
+    './build.sh',
+], lang='swift')