Idempotent Migrations on HasDefaultValueSql or HasComputedColumnSql with line breaks adds whitespace

[lajones]

If the user creates a model using HasDefaultValueSql(xyz) and the string xyz has line breaks in it, and if the user produces an idempotent SQL script by using Script-Migration -Idemptotent, then extra spaces are added to the value they passed in. E.g. if they call

HasDefaultValueSql("'Don't
GO
this way'")

then the SQL generated will look like this:

IF NOT EXISTS(SELECT * FROM [__EFMigrationsHistory] WHERE [MigrationId] = N'some_migration_identifier')
BEGIN
    CREATE TABLE [TestEntity] (
        [Id] int NOT NULL IDENTITY,
        [Name] nvarchar(max) NULL DEFAULT N'Don''t
    GO
    this way',
        CONSTRAINT [PK_TestEntity] PRIMARY KEY ([Id])
    );
END;

Note that, because of the indentation, extra spaces have been added before 'GO' and 'this way'.

Similarly for HasComputedColumnSql().

But note: there is a workaround - the user can pass the following instead:

HasDefaultValueSql("CONCAT('Don't, CHAR(13), CHAR(10), 'GO', CHAR(13), CHAR(10), 'this way')")

[ajcvickers]

Team discussion: consider warning in model validation. (Can warn for any new-line in the SQL; no need to only warn when it is in a literal.) Seems low priority.