From 161abb094d3ff714f1b31d9b21b1c4a463b53f17 Mon Sep 17 00:00:00 2001
From: Philip O'Toole <philip.otoole@yahoo.com>
Date: Wed, 11 Aug 2021 21:19:10 -0400
Subject: [PATCH] Add db-level FK constraints unit test

---
 db/db_test.go | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/db/db_test.go b/db/db_test.go
index 138810e4..ca880dfc 100644
--- a/db/db_test.go
+++ b/db/db_test.go
@@ -113,6 +113,68 @@ func Test_TableCreationInMemory(t *testing.T) {
 	}
 }
 
+// Test_TableCreationInMemoryFK ensures foreign key constraints work
+func Test_TableCreationInMemoryFK(t *testing.T) {
+	createTableFoo := "CREATE TABLE foo (id INTEGER NOT NULL PRIMARY KEY, name TEXT)"
+	createTableBar := "CREATE TABLE bar (fooid INTEGER NOT NULL PRIMARY KEY, FOREIGN KEY(fooid) REFERENCES foo(id))"
+	insertIntoBar := "INSERT INTO bar(fooid) VALUES(1)"
+
+	db := mustCreateInMemoryDatabase()
+	defer db.Close()
+
+	r, err := db.ExecuteStringStmt(createTableFoo)
+	if err != nil {
+		t.Fatalf("failed to create table: %s", err.Error())
+	}
+	if exp, got := `[{}]`, asJSON(r); exp != got {
+		t.Fatalf("unexpected results for query, expected %s, got %s", exp, got)
+	}
+
+	r, err = db.ExecuteStringStmt(createTableBar)
+	if err != nil {
+		t.Fatalf("failed to create table: %s", err.Error())
+	}
+	if exp, got := `[{}]`, asJSON(r); exp != got {
+		t.Fatalf("unexpected results for query, expected %s, got %s", exp, got)
+	}
+
+	r, err = db.ExecuteStringStmt(insertIntoBar)
+	if err != nil {
+		t.Fatalf("failed to insert record: %s", err.Error())
+	}
+	if exp, got := `[{"last_insert_id":1,"rows_affected":1}]`, asJSON(r); exp != got {
+		t.Fatalf("unexpected results for query, expected %s, got %s", exp, got)
+	}
+
+	// Now, do same testing with FK constraints enabled.
+	dbFK := mustCreateInMemoryDatabaseFK()
+	defer dbFK.Close()
+
+	r, err = dbFK.ExecuteStringStmt(createTableFoo)
+	if err != nil {
+		t.Fatalf("failed to create table: %s", err.Error())
+	}
+	if exp, got := `[{}]`, asJSON(r); exp != got {
+		t.Fatalf("unexpected results for query, expected %s, got %s", exp, got)
+	}
+
+	r, err = dbFK.ExecuteStringStmt(createTableBar)
+	if err != nil {
+		t.Fatalf("failed to create table: %s", err.Error())
+	}
+	if exp, got := `[{}]`, asJSON(r); exp != got {
+		t.Fatalf("unexpected results for query, expected %s, got %s", exp, got)
+	}
+
+	r, err = dbFK.ExecuteStringStmt(insertIntoBar)
+	if err != nil {
+		t.Fatalf("failed to insert record: %s", err.Error())
+	}
+	if exp, got := `[{"error":"FOREIGN KEY constraint failed"}]`, asJSON(r); exp != got {
+		t.Fatalf("unexpected results for query, expected %s, got %s", exp, got)
+	}
+}
+
 func Test_SQLiteMasterTable(t *testing.T) {
 	db, path := mustCreateDatabase()
 	defer db.Close()
@@ -1425,6 +1487,14 @@ func mustCreateInMemoryDatabase() *DB {
 	return db
 }
 
+func mustCreateInMemoryDatabaseFK() *DB {
+	db, err := OpenInMemory(true)
+	if err != nil {
+		panic("failed to open in-memory database with foreign key constraints")
+	}
+	return db
+}
+
 func mustWriteAndOpenDatabase(b []byte) (*DB, string) {
 	var err error
 	f := mustTempFile()