test: cover insertUpdateDeleteAgainstAViewAreRejected

src/test/kotlin/kestrel/ViewTest.kt

@@ -155,3 +155,134 @@ class ViewTest {
         assertFailsWith<KestrelException> { run("DROP VIEW users") }
     }
 
+    @Test
+    fun insertUpdateDeleteAgainstAViewAreRejected() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id, name FROM users WHERE age >= 18")
+        assertFailsWith<KestrelException> { run("INSERT INTO adults VALUES (9, 'x')") }
+        assertFailsWith<KestrelException> { run("UPDATE adults SET name = 'x'") }
+        assertFailsWith<KestrelException> { run("DELETE FROM adults") }
+    }
+
+    @Test
+    fun creatingAnIndexOnAViewIsRejected() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id, name FROM users WHERE age >= 18")
+        assertFailsWith<KestrelException> { run("CREATE INDEX idx ON adults (id)") }
+    }
+
+    @Test
+    fun mutuallyRecursiveViewsFailInsteadOfOverflowingTheStack() {
+        seedUsers()
+        run("CREATE VIEW a AS SELECT id FROM users")
+        run("CREATE VIEW b AS SELECT id FROM a")
+        run("CREATE OR REPLACE VIEW a AS SELECT id FROM b")
+        assertFailsWith<KestrelException> { run("SELECT * FROM a") }
+    }
+
+    @Test
+    fun selfReferencingViewFailsCleanly() {
+        seedUsers()
+        run("CREATE VIEW a AS SELECT id FROM users")
+        run("CREATE OR REPLACE VIEW a AS SELECT id FROM a")
+        assertFailsWith<KestrelException> { run("SELECT * FROM a") }
+    }
+
+    @Test
+    fun rollbackUndoesCreateViewAndDropView() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id FROM users WHERE age >= 18")
+        run("BEGIN")
+        run("CREATE VIEW seniors AS SELECT id FROM users WHERE age >= 60")
+        run("DROP VIEW adults")
+        run("ROLLBACK")
+        assertEquals(listOf("adults"), catalog.viewNames)
+    }
+
+    @Test
+    fun commitKeepsViewChanges() {
+        seedUsers()
+        run("BEGIN")
+        run("CREATE VIEW adults AS SELECT id FROM users WHERE age >= 18")
+        run("COMMIT")
+        assertEquals(listOf("adults"), catalog.viewNames)
+    }
+
+    @Test
+    fun dropTableWithADependentViewFailsByDefaultAndAlsoWithExplicitRestrict() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id FROM users WHERE age >= 18")
+        assertFailsWith<KestrelException> { run("DROP TABLE users") }
+        assertFailsWith<KestrelException> { run("DROP TABLE users RESTRICT") }
+        assertEquals(listOf("users"), catalog.tableNames)
+        assertEquals(listOf("adults"), catalog.viewNames)
+    }
+
+    @Test
+    fun dropTableCascadeDropsTheTableAndItsDependentView() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id FROM users WHERE age >= 18")
+        run("DROP TABLE users CASCADE")
+        assertTrue(catalog.tableNames.isEmpty())
+        assertTrue(catalog.viewNames.isEmpty())
+    }
+
+    @Test
+    fun dropViewWithADependentViewFailsByDefault() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id FROM users WHERE age >= 18")
+        run("CREATE VIEW seniorAdults AS SELECT id FROM adults WHERE id > 0")
+        assertFailsWith<KestrelException> { run("DROP VIEW adults") }
+        assertEquals(listOf("adults", "seniorAdults"), catalog.viewNames)
+    }
+
+    @Test
+    fun dropViewCascadeDropsATransitiveChainOfDependentViews() {
+        seedUsers()
+        run("CREATE VIEW a AS SELECT id FROM users WHERE age >= 18")
+        run("CREATE VIEW b AS SELECT id FROM a WHERE id > 0")
+        run("CREATE VIEW c AS SELECT id FROM b WHERE id > 0")
+        run("DROP VIEW a CASCADE")
+        assertTrue(catalog.viewNames.isEmpty())
+    }
+
+    @Test
+    fun dropTableCascadeHandlesADiamondOfDependentViewsWithoutFailing() {
+        seedUsers()
+        run("CREATE VIEW b AS SELECT id FROM users WHERE age >= 18")
+        run("CREATE VIEW c AS SELECT id FROM users WHERE age >= 21")
+        run("CREATE VIEW d AS SELECT b.id FROM b JOIN c ON b.id = c.id")
+        run("DROP TABLE users CASCADE")
+        assertTrue(catalog.tableNames.isEmpty())
+        assertTrue(catalog.viewNames.isEmpty())
+    }
+
+    @Test
+    fun rollbackUndoesACascadeDrop() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id FROM users WHERE age >= 18")
+        run("BEGIN")
+        run("DROP TABLE users CASCADE")
+        run("ROLLBACK")
+        assertEquals(listOf("users"), catalog.tableNames)
+        assertEquals(listOf("adults"), catalog.viewNames)
+        val result = select("SELECT id FROM adults ORDER BY id ASC")
+        assertTrue(result.rows.isNotEmpty())
+    }
+
+    @Test
+    fun explainOverAViewDescribesTheOuterQuery() {
+        seedUsers()
+        run("CREATE VIEW adults AS SELECT id, name FROM users WHERE age >= 18")
+        val explain = exec("EXPLAIN SELECT * FROM adults") as kestrel.engine.ExplainResult
+        assertTrue(explain.plan.any { it.contains("adults") })
+    }
+
+    @Test
+    fun columnTypeOfAViewIsInferredFromActualData() {
+        seedUsers()
+        run("CREATE VIEW names AS SELECT name FROM users")
+        val result = select("SELECT name FROM names WHERE name = 'ada'")
+        assertEquals(listOf(listOf(text("ada"))), result.rows)
+    }
+}