feat: add output file for export-schema (#3033)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Patrick Arminio <patrick.arminio@gmail.com>

RELEASE.md

@@ -0,0 +1,3 @@
+Release type: minor
+
+Adds a new flag to `export-schema` command, `--output`, which allows the user to specify the output file. If unset (current behavior), the command will continue to print to stdout.

docs/guides/schema-export.md

@@ -25,3 +25,9 @@ In order to store the exported schema in a file, pipes or redirection can be uti
 ```bash
 strawberry export-schema package.module:schema > schema.graphql
 ```
+
+Alternatively, the `--output` option can be used:
+
+```bash
+strawberry export-schema package.module:schema --output schema.graphql
+```

strawberry/cli/commands/export_schema.py

@@ -1,3 +1,5 @@
+from pathlib import Path
+
 import typer
 
 from strawberry.cli.app import app
@@ -18,7 +20,19 @@ def export_schema(
             "Works the same as `--app-dir` in uvicorn."
         ),
     ),
+    output: Path = typer.Option(
+        None,
+        "--output",
+        "-o",
+        help="File to save the exported schema. If not provided, prints to console.",
+    ),
 ) -> None:
     schema_symbol = load_schema(schema, app_dir)
 
-    print(print_schema(schema_symbol))  # noqa: T201
+    schema_text = print_schema(schema_symbol)
+
+    if output:
+        Path(output).write_text(schema_text)
+        typer.echo(f"Schema exported to {output}")
+    else:
+        print(schema_text)  # noqa: T201

tests/cli/test_export_schema.py

@@ -67,3 +67,25 @@ def test_invalid_schema_instance(cli_app: Typer, cli_runner: CliRunner):
 
     assert result.exit_code == 2
     assert expected_error in result.stdout.replace("\n", "")
+
+
+def test_output_option(cli_app: Typer, cli_runner: CliRunner, tmp_path):
+    selector = "tests.fixtures.sample_package.sample_module:schema"
+    output = tmp_path / "schema.graphql"
+    output_commands = ["--output", "-o"]
+    for output_command in output_commands:
+        result = cli_runner.invoke(
+            cli_app, ["export-schema", selector, output_command, str(output)]
+        )
+
+        assert result.exit_code == 0
+        assert output.read_text() == (
+            "type Query {\n"
+            "  user: User!\n"
+            "}\n"
+            "\n"
+            "type User {\n"
+            "  name: String!\n"
+            "  age: Int!\n"
+            "}"
+        )