MigrationTestHelper
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Cmn
class MigrationTestHelper
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android
open class MigrationTestHelper
A class that can help test and verify database creation and migration at different versions with different schemas.
Common usage of this helper is to create a database at an older version first and then attempt a migration and validation:
@Test
fun migrationTest() {
val migrationTestHelper = getMigrationTestHelper()
// Create the database at version 1
val newConnection = migrationTestHelper.createDatabase(1)
// Insert some data that should be preserved
newConnection.execSQL("INSERT INTO Pet (id, name) VALUES (1, 'Tom')")
newConnection.close()
// Migrate the database to version 2
val migratedConnection =
migrationTestHelper.runMigrationsAndValidate(2, listOf(MIGRATION_1_2)))
migratedConnection.prepare("SELECT * FROM Pet).use { stmt ->
// Validates data is preserved between migrations.
assertThat(stmt.step()).isTrue()
assertThat(stmt.getText(1)).isEqualTo("Tom")
}
migratedConnection.close()
}
The helper relies on exported schemas so androidx.room.Database.exportSchema should be enabled. Schema location should be configured via Room's Gradle Plugin (id 'androidx.room'):
room {
schemaDirectory("$projectDir/schemas")
}
The helper is then instantiated to use the same schema location where they are exported to. See platform-specific documentation for further configuration.
Summary
Public constructors |
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MigrationTestHelper(Creates a new migration helper. |
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This function is deprecated. Cannot be used to run migration tests involving auto migrations. |
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MigrationTestHelper(Creates a new migration helper. |
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MigrationTestHelper(Creates a new migration helper. |
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MigrationTestHelper( |
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MigrationTestHelper( |
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Public functions |
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open Statement |
apply(p0: Statement, p1: Description) |
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open Statement |
apply(p0: Statement, p1: Description) |
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open Unit |
Registers a database connection to be automatically closed when the test finishes. |
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open Unit |
Registers a database connection to be automatically closed when the test finishes. |
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SQLiteConnection |
createDatabase(version: Int)Creates the database at the given version. |
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open SupportSQLiteDatabase |
createDatabase(name: String, version: Int)Creates the database in the given version. |
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Unit |
finished() |
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SQLiteConnection |
runMigrationsAndValidate(version: Int, migrations: List<Migration>)Runs the given set of migrations on the existing database once created via |
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open SupportSQLiteDatabase |
runMigrationsAndValidate(Runs the given set of migrations on the provided database. |
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Protected functions |
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open Unit |
failed(p0: Throwable, p1: Description) |
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open Unit |
failed(p0: Throwable, p1: Description) |
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open Unit |
finished(description: Description?) |
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open Unit |
finished(description: Description?) |
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open Unit |
This function is deprecated. Deprecated in Java |
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open Unit |
This function is deprecated. Deprecated in Java |
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open Unit |
skipped(p0: AssumptionViolatedException, p1: Description) |
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open Unit |
skipped(p0: AssumptionViolatedException, p1: Description) |
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open Unit |
starting(description: Description?) |
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open Unit |
starting(p0: Description) |
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open Unit |
succeeded(p0: Description) |
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open Unit |
succeeded(p0: Description) |
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Public constructors
MigrationTestHelper
MigrationTestHelper(
instrumentation: Instrumentation,
databaseClass: Class<RoomDatabase>
)
Creates a new migration helper. It uses the instrumentation context to load the schema (falls back to the app resources) and the target context to create the database.
When the MigrationTestHelper is created with this constructor configuration then only createDatabase and runMigrationsAndValidate that return SupportSQLiteDatabase can be used.
| Parameters | |
|---|---|
instrumentation: Instrumentation |
The instrumentation instance. |
databaseClass: Class<RoomDatabase> |
The Database class to be tested. |
MigrationTestHelper
MigrationTestHelper(
instrumentation: Instrumentation,
assetsFolder: String,
openFactory: SupportSQLiteOpenHelper.Factory = FrameworkSQLiteOpenHelperFactory()
)
Creates a new migration helper. It uses the instrumentation context to load the schema (falls back to the app resources) and the target context to create the database.
When the MigrationTestHelper is created with this constructor configuration then only createDatabase and runMigrationsAndValidate that return SupportSQLiteDatabase can be used.
| Parameters | |
|---|---|
instrumentation: Instrumentation |
The instrumentation instance. |
assetsFolder: String |
The asset folder in the assets directory. |
openFactory: SupportSQLiteOpenHelper.Factory = FrameworkSQLiteOpenHelperFactory() |
factory for creating an |
MigrationTestHelper
MigrationTestHelper(
instrumentation: Instrumentation,
databaseClass: Class<RoomDatabase>,
specs: List<AutoMigrationSpec>,
openFactory: SupportSQLiteOpenHelper.Factory = FrameworkSQLiteOpenHelperFactory()
)
Creates a new migration helper. It uses the instrumentation context to load the schema (falls back to the app resources) and the target context to create the database.
Instances of classes annotated with androidx.room.ProvidedAutoMigrationSpec have provided using this constructor. MigrationTestHelper will map auto migration spec classes to their provided instances before running and validating the migrations.
When the MigrationTestHelper is created with this constructor configuration then only createDatabase and runMigrationsAndValidate that return SupportSQLiteDatabase can be used.
| Parameters | |
|---|---|
instrumentation: Instrumentation |
The instrumentation instance. |
databaseClass: Class<RoomDatabase> |
The Database class to be tested. |
specs: List<AutoMigrationSpec> |
The list of available auto migration specs that will be provided to the RoomDatabase at runtime. |
openFactory: SupportSQLiteOpenHelper.Factory = FrameworkSQLiteOpenHelperFactory() |
factory for creating an |
MigrationTestHelper
MigrationTestHelper(
instrumentation: Instrumentation,
file: File,
driver: SQLiteDriver,
databaseClass: KClass<RoomDatabase>,
databaseFactory: () -> RoomDatabase = { findAndInstantiateDatabaseImpl(databaseClass.java) },
autoMigrationSpecs: List<AutoMigrationSpec> = emptyList()
)
Creates a new migration helper. It uses the instrumentation context to load the schema (falls back to the app resources) and the target context to create the database.
When the MigrationTestHelper is created with this constructor configuration then only createDatabase and runMigrationsAndValidate that return SQLiteConnection can be used.
| Parameters | |
|---|---|
instrumentation: Instrumentation |
The instrumentation instance. |
file: File |
The database file. |
driver: SQLiteDriver |
A driver that opens connection to a file database. A driver that opens connections to an in-memory database would be meaningless. |
databaseClass: KClass<RoomDatabase> |
The |
databaseFactory: () -> RoomDatabase = {
findAndInstantiateDatabaseImpl(databaseClass.java)
} |
An optional factory function to create an instance of the |
autoMigrationSpecs: List<AutoMigrationSpec> = emptyList() |
The list of |
MigrationTestHelper
MigrationTestHelper(
schemaDirectoryPath: Path,
databasePath: Path,
driver: SQLiteDriver,
databaseClass: KClass<RoomDatabase>,
databaseFactory: () -> RoomDatabase = { findAndInstantiateDatabaseImpl(databaseClass.java) },
autoMigrationSpecs: List<AutoMigrationSpec> = emptyList()
)
| Parameters | |
|---|---|
schemaDirectoryPath: Path |
The schema directory where schema files are exported. |
databasePath: Path |
Name of the database. |
driver: SQLiteDriver |
A driver that opens connection to a file database. A driver that opens connections to an in-memory database would be meaningless. |
databaseClass: KClass<RoomDatabase> |
The |
databaseFactory: () -> RoomDatabase = {
findAndInstantiateDatabaseImpl(databaseClass.java)
} |
An optional factory function to create an instance of the |
autoMigrationSpecs: List<AutoMigrationSpec> = emptyList() |
The list of |
MigrationTestHelper
MigrationTestHelper(
schemaDirectoryPath: String,
fileName: String,
driver: SQLiteDriver,
databaseClass: KClass<RoomDatabase>,
databaseFactory: () -> RoomDatabase,
autoMigrationSpecs: List<AutoMigrationSpec> = emptyList()
)
| Parameters | |
|---|---|
schemaDirectoryPath: String |
The schema directory where schema files are exported. |
fileName: String |
Name of the database. |
driver: SQLiteDriver |
A driver that opens connection to a file database. A driver that opens connections to an in-memory database would be meaningless. |
databaseClass: KClass<RoomDatabase> |
The |
databaseFactory: () -> RoomDatabase |
The factory function to create an instance of the |
autoMigrationSpecs: List<AutoMigrationSpec> = emptyList() |
The list of |
Public functions
closeWhenFinished
open fun closeWhenFinished(db: RoomDatabase): Unit
Registers a database connection to be automatically closed when the test finishes.
This only works if MigrationTestHelper is registered as a Junit test rule via the org.junit.Rule annotation.
| Parameters | |
|---|---|
db: RoomDatabase |
The RoomDatabase instance which holds the database. |
closeWhenFinished
open fun closeWhenFinished(db: SupportSQLiteDatabase): Unit
Registers a database connection to be automatically closed when the test finishes.
This only works if MigrationTestHelper is registered as a Junit test rule via the org.junit.Rule annotation.
| Parameters | |
|---|---|
db: SupportSQLiteDatabase |
The database connection that should be closed after the test finishes. |
createDatabase
fun createDatabase(version: Int): SQLiteConnection
Creates the database at the given version.
Once a database is created it can further validate with runMigrationsAndValidate.
| Parameters | |
|---|---|
version: Int |
The version of the schema at which the database should be created. |
| Returns | |
|---|---|
SQLiteConnection |
A database connection of the newly created database. |
| Throws | |
|---|---|
kotlin.IllegalStateException |
If a new database was not created. |
createDatabase
open fun createDatabase(name: String, version: Int): SupportSQLiteDatabase
Creates the database in the given version.
If the database file already exists, it tries to delete it first. If delete fails, throws an exception.
| Parameters | |
|---|---|
name: String |
The name of the database. |
version: Int |
The version in which the database should be created. |
| Returns | |
|---|---|
SupportSQLiteDatabase |
A database connection which has the schema in the requested version. |
runMigrationsAndValidate
fun runMigrationsAndValidate(
version: Int,
migrations: List<Migration> = emptyList()
): SQLiteConnection
Runs the given set of migrations on the existing database once created via createDatabase.
This function uses the same algorithm that Room performs to choose migrations such that the migrations instances provided must be sufficient to bring the database from current version to the desired version. If the database contains androidx.room.AutoMigrations, then those are already included in the list of migrations to execute if necessary. Note that provided manual migrations take precedence over auto migrations if they overlap in migration paths.
Once migrations are done, this functions validates the database schema to ensure the migration performed resulted in the expected schema.
| Parameters | |
|---|---|
version: Int |
The final version the database should migrate to. |
migrations: List<Migration> = emptyList() |
The list of migrations used to attempt the database migration. |
| Returns | |
|---|---|
SQLiteConnection |
A database connection of the migrated database. |
| Throws | |
|---|---|
kotlin.IllegalStateException |
If the schema validation fails. |
runMigrationsAndValidate
open fun runMigrationsAndValidate(
name: String,
version: Int,
validateDroppedTables: Boolean,
vararg migrations: Migration
): SupportSQLiteDatabase
Runs the given set of migrations on the provided database.
It uses the same algorithm that Room uses to choose migrations so the migrations instances that are provided to this method must be sufficient to bring the database from current version to the desired version.
After the migration, the method validates the database schema to ensure that migration result matches the expected schema. Handling of dropped tables depends on the validateDroppedTables argument. If set to true, the verification will fail if it finds a table that is not registered in the Database. If set to false, extra tables in the database will be ignored (this is the runtime library behavior).
| Parameters | |
|---|---|
name: String |
The database name. You must first create this database via |
version: Int |
The final version after applying the migrations. |
validateDroppedTables: Boolean |
If set to true, validation will fail if the database has unknown tables. |
vararg migrations: Migration |
The list of available migrations. |
| Throws | |
|---|---|
kotlin.IllegalStateException |
If the schema validation fails. |