Add SQL FK regression coverage for #1443

changelog.d/unreleased/1443.fixed.md

@@ -0,0 +1,15 @@
+---
+category: fixed
+issues:
+  - 1443
+affected:
+  - tests/CodeIndex.Tests/ReferenceExtractorTests.cs
+---
+
+## English
+
+- **SQL foreign-key reference coverage is now regression-tested for ALTER TABLE ADD CONSTRAINT (#1443)** — the SQL reference extractor test suite now locks inline and ALTER-style foreign-key references to the referenced table.
+
+## 日本語
+
+- **SQL foreign key reference の ALTER TABLE ADD CONSTRAINT 対応を回帰テストで固定しました (#1443)** — SQL reference extractor のテストで、inline と ALTER 形式の foreign key が参照先 table を参照として拾うことを固定しました。

tests/CodeIndex.Tests/ReferenceExtractorTests.cs

@@ -14718,6 +14718,26 @@ public void Extract_SQL_AlterTableCapturesTargetReference()
         Assert.DoesNotContain(references, r => r.SymbolName == "sales" && r.ReferenceKind == "reference");
     }
 
+    [Fact]
+    public void Extract_SQL_AlterTableAddConstraintForeignKeyCapturesReferencedTable()
+    {
+        const string content = """
+            CREATE TABLE orders (id int PRIMARY KEY);
+            CREATE TABLE order_items (order_id int REFERENCES orders(id));
+            ALTER TABLE order_items ADD CONSTRAINT fk_order
+                FOREIGN KEY (order_id) REFERENCES orders(id);
+            """;
+
+        var symbols = SymbolExtractor.Extract(1, "sql", content);
+        var references = ReferenceExtractor.Extract(1, "sql", content, symbols);
+
+        Assert.Contains(references, r => r.SymbolName == "order_items" && r.ReferenceKind == "reference" && r.Line == 3);
+        Assert.Equal(2, references.Count(r => r.SymbolName == "orders" && r.ReferenceKind == "reference"));
+        Assert.Contains(references, r => r.SymbolName == "orders" && r.ReferenceKind == "reference" && r.Line == 2);
+        Assert.Contains(references, r => r.SymbolName == "orders" && r.ReferenceKind == "reference" && r.Line == 4);
+        Assert.DoesNotContain(references, r => r.SymbolName == "fk_order" && r.ReferenceKind == "reference");
+    }
+
     [Fact]
     public void Extract_SQL_GeneratedColumnsCaptureExpressionDependencies()
     {