Reformat and review feedback

Author: simolus3

integrations/sqldelight-test-database/src/commonMain/sqldelight/com/powersync/integrations/sqldelight/todos.sq

@@ -9,3 +9,6 @@ SELECT * FROM todos;
 
 create:
 INSERT INTO todos (id, title, content) VALUES (uuid(), ?, ?);
+
+update:
+UPDATE todos SET content = content || title RETURNING *;

integrations/sqldelight/README.md

@@ -53,9 +53,9 @@ There are also some limitations to be aware of:
 1. Due to historical reasons, the PowerSync SDK migrates all databases to `user_version` 1 when
    created (but it will never downgrade a database).
    So if you want to use SQLDelight's schema tools, the first version would have to be `2`.
-2. While you can write `CREATE TABLE` statements in your `.sq` files, note that these aren't
-   actually used - you still have to define your PowerSync schema and the SDK will auto-create the
-   tables from there.
+2. The `CREATE TABLE` statements in your `.sq` files are only used at build time to verify your
+   queries. At runtime, PowerSync will create tables from your schema as views, the defined
+   statements are ignored.
    If you want to use the schema managed by SQLDelight, configure PowerSync to use
    [raw tables](https://docs.powersync.com/usage/use-case-examples/raw-tables).
 3. Functions and tables contributed by the PowerSync core extension are not visible to `.sq` files

integrations/sqldelight/src/appleTest/kotlin/com/powersync/integrations/sqldelight/SqlDelightTest.apple.kt

@@ -2,6 +2,4 @@ package com.powersync.integrations.sqldelight
 
 import com.powersync.DatabaseDriverFactory
 
-actual fun databaseDriverFactory(): DatabaseDriverFactory {
-    return DatabaseDriverFactory()
-}
+actual fun databaseDriverFactory(): DatabaseDriverFactory = DatabaseDriverFactory()

integrations/sqldelight/src/commonIntegrationTest/kotlin/com/powersync/integrations/sqldelight/SqlDelightTest.kt

@@ -1,6 +1,7 @@
 package com.powersync.integrations.sqldelight
 
 import app.cash.sqldelight.async.coroutines.awaitAsList
+import app.cash.sqldelight.async.coroutines.awaitAsOne
 import app.cash.sqldelight.coroutines.asFlow
 import app.cash.sqldelight.coroutines.mapToList
 import app.cash.turbine.turbineScope
@@ -85,6 +86,28 @@ class SqlDelightTest {
             }
         }
 
+    @Test
+    fun testReturningQuery() =
+        databaseTest { powersync ->
+            val db = TestDatabase(PowerSyncDriver(powersync, this))
+            turbineScope {
+                db.todosQueries.create("title", "content")
+
+                val query =
+                    db.todosQueries
+                        .all()
+                        .asFlow()
+                        .mapToList(currentCoroutineContext())
+                        .testIn(this)
+                query.awaitItem() shouldHaveSize 1
+
+                val updatedItem = db.todosQueries.update().awaitAsOne()
+                updatedItem.content shouldBe "contenttitle"
+                query.awaitItem() shouldBe listOf(updatedItem)
+                query.cancelAndIgnoreRemainingEvents()
+            }
+        }
+
     @Test
     fun testTransaction() =
         databaseTest { powersync ->

integrations/sqldelight/src/commonMain/kotlin/com/powersync/integrations/sqldelight/PowerSyncDriver.kt

@@ -56,6 +56,10 @@ public class PowerSyncDriver(
         binders: (SqlPreparedStatement.() -> Unit)?,
     ): QueryResult<R> =
         QueryResult.AsyncValue {
+            // Despite being a query, this is not guaranteed to be read-only: RETURNING statements
+            // also use this.
+            // So, always using the write connection is a safe default. In the future we may want to
+            // analyze the statement to potentially route it to a read connection if possible.
             withConnection { connection ->
                 connection.usePrepared(sql) { stmt ->
                     val wrapper = StatementWrapper(stmt)
@@ -81,8 +85,11 @@ public class PowerSyncDriver(
                     while (stmt.step()) {
                         // Keep stepping through statement
                     }
+                }
 
-                    0L
+                connection.usePrepared("SELECT changes()") {
+                    check(it.step())
+                    it.getLong(0)
                 }
             }
         }

integrations/sqldelight/src/jvmTest/kotlin/com/powersync/integrations/sqldelight/SqlDelightTest.jvm.kt

@@ -2,6 +2,4 @@ package com.powersync.integrations.sqldelight
 
 import com.powersync.DatabaseDriverFactory
 
-actual fun databaseDriverFactory(): DatabaseDriverFactory {
-    return DatabaseDriverFactory()
-}
+actual fun databaseDriverFactory(): DatabaseDriverFactory = DatabaseDriverFactory()