From 999220e835ace284390ee77b39831437eee1e521 Mon Sep 17 00:00:00 2001
From: David Pugh <djpugh@gmail.com>
Date: Fri, 14 Aug 2026 13:15:01 +0100
Subject: [PATCH] adding json flag

---
 src/nskit/cli/app.py            | 10 +++++++-
 tests/unit/test_cli/test_app.py | 43 +++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/src/nskit/cli/app.py b/src/nskit/cli/app.py
index 29ccb04..06c6e2b 100644
--- a/src/nskit/cli/app.py
+++ b/src/nskit/cli/app.py
@@ -150,8 +150,12 @@ def create_cli(
         backend = None
 
     @app.command(name="list", help="List available recipes.")
-    def list_recipes():
+    def list_recipes(
+        json_output: Annotated[bool, typer.Option("--json", help="Output as JSON array of recipe names.")] = False,
+    ):
         """List available recipes from backend or installed entry points."""
+        import json as json_mod
+
         if client:
             recipes = client.list_recipes()
         else:
@@ -161,6 +165,10 @@ def list_recipes():
             names = get_extension_names(recipe_entrypoint)
             recipes = [RecipeInfo(name=n, versions=["local"]) for n in names]
 
+        if json_output:
+            print(json_mod.dumps(sorted(r.name for r in recipes)))
+            return
+
         if not recipes:
             rich_print("[yellow]No recipes found[/yellow]")
             return
diff --git a/tests/unit/test_cli/test_app.py b/tests/unit/test_cli/test_app.py
index edf2ac4..8a8f50d 100644
--- a/tests/unit/test_cli/test_app.py
+++ b/tests/unit/test_cli/test_app.py
@@ -229,3 +229,46 @@ def test_no_push_when_declined(self, tmp_path):
         _commit_and_maybe_push(project, "proj", "", False, mock_vcs, console)
 
         mock_vcs.create.assert_not_called()
+
+
+class TestListJsonFlag:
+    """``list --json`` outputs a machine-readable JSON array."""
+
+    def test_list_json_exits_zero(self, runner):
+        app = create_cli(recipe_entrypoint="nskit.recipes")
+        result = runner.invoke(app, ["list", "--json"])
+        assert result.exit_code == 0, result.output
+
+    def test_list_json_outputs_valid_json(self, runner):
+        import json
+
+        app = create_cli(recipe_entrypoint="nskit.recipes")
+        result = runner.invoke(app, ["list", "--json"])
+        data = json.loads(result.output)
+        assert isinstance(data, list)
+
+    def test_list_json_contains_registered_recipes(self, runner):
+        import json
+
+        app = create_cli(recipe_entrypoint="nskit.recipes")
+        result = runner.invoke(app, ["list", "--json"])
+        data = json.loads(result.output)
+        assert "python_package" in data
+
+    def test_list_json_is_sorted(self, runner):
+        import json
+
+        app = create_cli(recipe_entrypoint="nskit.recipes")
+        result = runner.invoke(app, ["list", "--json"])
+        data = json.loads(result.output)
+        assert data == sorted(data)
+
+    def test_list_without_json_shows_table(self, runner):
+        """Without --json, output is a rich table (not JSON)."""
+        import json
+
+        app = create_cli(recipe_entrypoint="nskit.recipes")
+        result = runner.invoke(app, ["list"])
+        assert result.exit_code == 0
+        with pytest.raises(json.JSONDecodeError):
+            json.loads(result.output)