test(lint): add Starlark integration test for xpath_expressions and parse_xpath builtins

Addresses the missing integration test flagged in the PR mendixlabs#688 review.
Exercises the full pipeline: catalog seed → LoadStarlarkRule → rule.Check → violation assertions.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Andries-Smit

mdl/linter/starlark_xpath_integration_test.go

@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package linter_test
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/mendixlabs/mxcli/mdl/catalog"
+	"github.com/mendixlabs/mxcli/mdl/linter"
+)
+
+const xpathTestRule = `
+RULE_ID = "PERF001"
+RULE_NAME = "xpath builtins"
+DESCRIPTION = "exercises xpath_expressions and parse_xpath builtins"
+CATEGORY = "performance"
+SEVERITY = "info"
+
+def check():
+    out = []
+    for e in xpath_expressions():
+        ast = parse_xpath(e.xpath_expression)
+        out.append(violation(
+            message = "entry %s kind %s" % (e.document_qualified_name, ast.kind),
+        ))
+    return out
+`
+
+func TestStarlarkXPathBuiltins(t *testing.T) {
+	// Use a file-based catalog: an in-memory one pools separate connections, so
+	// inserts on one aren't visible to queries on another.
+	cat, err := catalog.NewFromFile(filepath.Join(t.TempDir(), "cat.db"))
+	if err != nil {
+		t.Fatalf("catalog.NewFromFile: %v", err)
+	}
+	defer cat.Close()
+	db := cat.CatalogDB()
+
+	// One retrieve action in module MyApp with a not(…) XPath.
+	if _, err := db.Exec(
+		`INSERT INTO xpath_expressions_data
+		 (Id, DocumentType, DocumentId, DocumentQualifiedName,
+		  ComponentType, ComponentId, XPathExpression,
+		  IsParameterized, UsageType, ModuleName, ProjectId, SnapshotId)
+		 VALUES ('x1','MICROFLOW','mf-1','MyApp.GetActiveItems',
+		         'RETRIEVE_ACTION','ra-1','[not(Status = ''MyApp.Status.Active'')]',
+		         0,'RETRIEVE','MyApp','default','s1')`); err != nil {
+		t.Fatal(err)
+	}
+
+	dir := t.TempDir()
+	path := filepath.Join(dir, "xpath_test.star")
+	if err := os.WriteFile(path, []byte(xpathTestRule), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	rule, err := linter.LoadStarlarkRule(path)
+	if err != nil {
+		t.Fatalf("LoadStarlarkRule: %v", err)
+	}
+
+	ctx := linter.NewLintContext(cat, nil)
+	violations := rule.Check(ctx)
+
+	var msgs []string
+	for _, v := range violations {
+		msgs = append(msgs, v.Message)
+	}
+	joined := strings.Join(msgs, "\n")
+
+	for _, want := range []string{
+		"entry MyApp.GetActiveItems", // xpath_expressions() returned the row
+		"kind unary",                 // parse_xpath() parsed not(…) as a unary node
+	} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("missing %q in violations:\n%s", want, joined)
+		}
+	}
+}