fix: schema not running table validation

core/src/commonMain/kotlin/com/powersync/db/schema/Schema.kt

@@ -4,5 +4,20 @@ import kotlinx.serialization.Serializable
 
 @Serializable
 public data class Schema(val tables: List<Table>) {
+    init {
+        validate()
+    }
+
     public constructor(vararg tables: Table) : this(tables.asList())
+
+
+    public fun validate() {
+        val tableNames = mutableSetOf<String>()
+        tables.forEach { table ->
+            if (!tableNames.add(table.name)) {
+                throw AssertionError("Duplicate table name: ${table.name}")
+            }
+            table.validate()
+        }
+    }
 }

core/src/commonTest/kotlin/com/powersync/db/schema/SchemaTest.kt

@@ -0,0 +1,40 @@
+package com.powersync.db.schema
+
+import kotlin.test.*
+
+class SchemaTest {
+
+    @Test
+    fun schemaConstructionWithValidTablesShouldSucceed() {
+        val table1 = Table("table1", listOf(Column("column1", ColumnType.TEXT)))
+        val table2 = Table("table2", listOf(Column("column2", ColumnType.INTEGER)))
+
+        val schema = Schema(table1, table2)
+
+        assertEquals(2, schema.tables.size)
+        assertEquals("table1", schema.tables[0].name)
+        assertEquals("table2", schema.tables[1].name)
+    }
+
+    @Test
+    fun schemaConstructionWithInvalidTableShouldThrowException() {
+        val validTable = Table("validTable", listOf(Column("column1", ColumnType.TEXT)))
+        val invalidTable = Table("#invalid-table", listOf(Column("column1", ColumnType.TEXT)))
+
+        val exception = assertFailsWith<AssertionError> {
+            Schema(validTable, invalidTable)
+        }
+        assertEquals(exception.message, "Invalid characters in table name: #invalid-table")
+    }
+
+    @Test
+    fun schemaShouldDetectDuplicateTableNames() {
+        val table1 = Table("table1", listOf(Column("column1", ColumnType.TEXT)))
+        val table2 = Table("table1", listOf(Column("column2", ColumnType.INTEGER)))
+
+        val exception = assertFailsWith<AssertionError> {
+            Schema(table1, table2)
+        }
+        assertEquals(exception.message, "Duplicate table name: table1")
+    }
+}

core/src/commonTest/kotlin/com/powersync/db/schema/TableTest.kt

@@ -154,4 +154,17 @@ class TableTest {
 
         assertEquals(exception.message,"Duplicate index users.name_index")
     }
+
+
+    @Test
+    fun testValidationOfIdColumn() {
+        val columns = listOf(Column("id", ColumnType.TEXT))
+        val table = Table("users", columns)
+
+        val exception = assertFailsWith<AssertionError> {
+            table.validate()
+        }
+
+        assertEquals(exception.message,"users: id column is automatically added, custom id columns are not supported")
+    }
 }