Add test for unexpected directory layout error

go/ql/integration-tests/all-platforms/go/diagnostics/unsupported-relative-path/diagnostics.expected

@@ -0,0 +1,14 @@
+{
+  "markdownMessage": "You should replace relative package paths (that contain `.` or `..`) with absolute paths. Alternatively you can [use a Go module](https://go.dev/blog/using-go-modules).",
+  "severity": "error",
+  "source": {
+    "extractorName": "go",
+    "id": "go/autobuilder/relative-import-paths",
+    "name": "Some imports use unsupported relative package paths"
+  },
+  "visibility": {
+    "cliSummaryTable": true,
+    "statusPage": true,
+    "telemetry": true
+  }
+}

go/ql/integration-tests/all-platforms/go/diagnostics/unsupported-relative-path/test.py

@@ -0,0 +1,9 @@
+import sys
+
+from create_database_utils import *
+from diagnostics_test_utils import *
+
+os.environ['GITHUB_REPOSITORY'] = "a/b"
+run_codeql_database_create([], lang="go", source="work", db=None, runFunction=runUnsuccessfully)
+
+check_diagnostics()

go/ql/integration-tests/all-platforms/go/diagnostics/unsupported-relative-path/work/main/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"./subpkg"
+)
+
+func main() {
+	subpkg.F()
+}

go/ql/integration-tests/all-platforms/go/diagnostics/unsupported-relative-path/work/main/subpkg/subpkg.go

@@ -0,0 +1,8 @@
+package subpkg
+
+import "fmt"
+
+func F() {
+	// It is required that there is an import in this package, which is import by another package using a local path
+	fmt.Println("subpkg.F")
+}