fix(integrations): drop invalid --model/--output-format flags from Vibe dispatch (#4784)

The Mistral Vibe CLI has no --model and no --output-format flag, so the
inherited SkillsIntegration.build_exec_args() made a dispatched step exit
2 at argument parsing whenever a model was configured or JSON output was
requested. Keep -p, map output_json to Vibe's own --output json, and
drop model: Vibe picks its model from active_model in its config.

Assisted-by: Claude Code (model: Claude Opus 5.5, autonomous)

Author: kartsan03

src/specify_cli/integrations/vibe/__init__.py

@@ -6,6 +6,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Mapping, Sequence
 from pathlib import Path
 from typing import Any
 
@@ -79,6 +80,33 @@ def options(cls) -> list[IntegrationOption]:
         )
         return opts
 
+    def build_exec_args(
+        self,
+        prompt: str,
+        *,
+        model: str | None = None,
+        output_json: bool = True,
+        integration_args: Sequence[str] | None = None,
+        integration_options: Mapping[str, Any] | None = None,
+        project_root: Path | None = None,
+    ) -> list[str] | None:
+        """Build CLI arguments for non-interactive ``vibe`` execution.
+
+        ``SkillsIntegration``'s default appends ``--model`` and
+        ``--output-format``, neither of which exists in the Vibe CLI, so a
+        dispatched step exits 2 at argument parsing whenever either flag ends
+        up appended (a configured ``model``, or ``output_json=True``). Vibe's
+        structured output is ``--output json``. ``model`` is deliberately
+        dropped: Vibe has no per-invocation model flag and selects its model
+        out of band via ``active_model`` in its config (or ``VIBE_ACTIVE_MODEL``).
+        """
+        self.validate_runtime_config(integration_args, integration_options)
+        args = [self._resolve_executable(), "-p", prompt]
+        self._apply_extra_args_env_var(args)
+        if output_json:
+            args.extend(["--output", "json"])
+        return args
+
     def _render_skill(self, template_name: str, frontmatter: dict[str, Any], body: str) -> str:
         """Render a processed command template as a Vibe skill."""
         skill_name = f"speckit-{template_name.replace('.', '-')}"

tests/integrations/test_integration_vibe.py

@@ -128,6 +128,54 @@ def test_skills_do_not_have_argument_hint(self, tmp_path):
                 f"{f.parent.name}/SKILL.md unexpectedly has argument-hint frontmatter"
             )
 
+    def test_build_exec_args_uses_prompt_mode(self):
+        integration = get_integration("vibe")
+
+        args = integration.build_exec_args(
+            "/speckit-specify build a login page",
+            output_json=False,
+        )
+
+        assert args == ["vibe", "-p", "/speckit-specify build a login page"]
+
+    def test_build_exec_args_requests_json_output(self):
+        """Vibe's structured output is `--output json`; it has no `--output-format`."""
+        integration = get_integration("vibe")
+
+        args = integration.build_exec_args("/speckit-plan add OAuth", output_json=True)
+
+        assert args == ["vibe", "-p", "/speckit-plan add OAuth", "--output", "json"]
+        assert "--output-format" not in args
+
+    def test_build_exec_args_omits_model_flag(self):
+        """Vibe has no model flag; passing `--model` exits 2 at argument parsing."""
+        integration = get_integration("vibe")
+
+        args = integration.build_exec_args(
+            "explain this repository",
+            model="mistral-medium-latest",
+            output_json=False,
+        )
+
+        assert args == ["vibe", "-p", "explain this repository"]
+        assert "--model" not in args
+        assert "mistral-medium-latest" not in args
+
+    def test_build_exec_args_applies_extra_args(self, monkeypatch):
+        monkeypatch.setenv("SPECKIT_INTEGRATION_VIBE_EXTRA_ARGS", "--auto-approve")
+        integration = get_integration("vibe")
+
+        args = integration.build_exec_args("check the build", output_json=True)
+
+        assert args == [
+            "vibe",
+            "-p",
+            "check the build",
+            "--auto-approve",
+            "--output",
+            "json",
+        ]
+
 
 class TestVibeTomlMerging:
     """Behavioral tests for the toml-vibe hooks.toml generation and cleanup."""