Resolve test artifacts path on macOS (/tmp/ symlink)

Author: elinor-fung

src/installer/tests/TestUtils/TestContext.cs

@@ -44,6 +44,18 @@ static TestContext()
 
             TestAssetsOutput = GetTestContextVariable("TEST_ASSETS_OUTPUT");
             TestArtifactsPath = GetTestContextVariable("TEST_ARTIFACTS");
+
+            // On macOS, /tmp/ is a symlink. Running apps out of it will resolve the path, so determine the resolved path here.
+            if (OperatingSystem.IsMacOS())
+            {
+                string tmpPath = "/tmp/";
+                DirectoryInfo tmp = new DirectoryInfo(tmpPath[..^1]); // No trailing slash in order to properly check the link target
+                if (tmp.LinkTarget != null && TestArtifactsPath.StartsWith(tmpPath))
+                {
+                    TestArtifactsPath = Path.Combine(tmp.ResolveLinkTarget(true).FullName, TestArtifactsPath[tmpPath.Length..]);
+                }
+            }
+
             Directory.CreateDirectory(TestArtifactsPath);
 
             // Create an empty global.json, so running tests from test artifacts is not affected