Support @file prefix for call --data

src/fulfil_cli/cli/commands/common.py

@@ -4,6 +4,7 @@
 
 import json
 import sys
+from pathlib import Path
 from typing import Any, NoReturn
 
 import click
@@ -52,3 +53,21 @@ def parse_json_arg(value: str, arg_name: str) -> Any:
     except json.JSONDecodeError as exc:
         console.print(f"[red]Invalid JSON for {arg_name}: {exc}[/red]")
         raise typer.Exit(code=EXIT_VALIDATION) from None
+
+
+def resolve_value_or_file(value: str, arg_name: str) -> str:
+    """Return *value*, or the contents of the referenced file when prefixed with '@'.
+
+    Follows the curl/gh convention: '@path/to/file.json' reads from the file.
+    Use '\\@literal' to pass a value that actually starts with a literal '@'.
+    """
+    if value.startswith("\\@"):
+        return value[1:]
+    if value.startswith("@"):
+        path = Path(value[1:])
+        try:
+            return path.read_text()
+        except OSError as exc:
+            console.print(f"[red]Cannot read file for {arg_name}: {exc}[/red]")
+            raise typer.Exit(code=EXIT_VALIDATION) from None
+    return value

src/fulfil_cli/cli/commands/model.py

@@ -10,7 +10,7 @@
 import typer
 from rich.console import Console
 
-from fulfil_cli.cli.commands.common import handle_error, parse_json_arg
+from fulfil_cli.cli.commands.common import handle_error, parse_json_arg, resolve_value_or_file
 from fulfil_cli.cli.state import AppContext, format_option
 from fulfil_cli.client.errors import EXIT_NOT_FOUND, EXIT_OK, EXIT_USAGE, FulfilError
 from fulfil_cli.output.formatter import output, output_model_describe
@@ -313,7 +313,10 @@ def count_cmd(ctx: click.Context, where: str | None, output_format: str | None)
     @click.option(
         "--data",
         default=None,
-        help=("Extra method arguments as a JSON object. Example: '{\"warehouse\": 1}'"),
+        help=(
+            "Extra method arguments as a JSON object. Example: '{\"warehouse\": 1}'. "
+            "Prefix with '@' to read from a file: --data @payload.json"
+        ),
     )
     @format_option
     @click.pass_context
@@ -339,7 +342,7 @@ def call_cmd(
         if ids:
             params["ids"] = _parse_ids(ids)
         if data:
-            extra = parse_json_arg(data, "--data")
+            extra = parse_json_arg(resolve_value_or_file(data, "--data"), "--data")
             if isinstance(extra, dict):
                 params.update(extra)
 

tests/test_cli/test_model_commands.py

@@ -306,6 +306,26 @@ def test_with_ids_and_data(self, httpx_mock, cli_env, jsonrpc_success):
         assert body["params"]["ids"] == [42]
         assert body["params"]["force"] is True
 
+    def test_data_from_file(self, httpx_mock, cli_env, jsonrpc_success, tmp_path):
+        httpx_mock.add_response(json=jsonrpc_success({"ok": True}))
+
+        payload = tmp_path / "payload.json"
+        payload.write_text('{"warehouse": 7, "force": true}')
+
+        result = runner.invoke(app, ["sale_order", "call", "process", "--data", f"@{payload}"])
+        assert result.exit_code == 0, result.stdout + result.stderr
+
+        body = json.loads(httpx_mock.get_request().content)
+        assert body["params"]["warehouse"] == 7
+        assert body["params"]["force"] is True
+
+    def test_data_file_missing(self, cli_env):
+        result = runner.invoke(
+            app, ["sale_order", "call", "process", "--data", "@/no/such/file.json"]
+        )
+        assert result.exit_code == 7
+        assert "Cannot read file" in (result.stdout + result.stderr)
+
 
 class TestDescribeCommand:
     def test_full_describe(self, httpx_mock, cli_env, jsonrpc_success):