Actually write to the output file when injecting (#117)

Author: kurtmckee

src/sqliteimport/cli.py

@@ -259,4 +259,5 @@ def main() -> None:
         sys.exit(1)
     prologue = injector.generate_prologue(database)
     code = target_file.read_text()
-    injector.inject_prologue(prologue, code, marker)
+    rendered_target = injector.inject_prologue(prologue, code, marker)
+    output_file.write_text(rendered_target)

src/sqliteimport/injector.py

@@ -68,6 +68,7 @@ def inject_prologue(prologue: str, code: str, marker: str) -> str:
             break
         lines.append(line)
     lines.extend(code_iter)
+    lines.append("")  # The trailing newline will be lost otherwise.
     return "\n".join(lines)