docs: document OpenCode provider setup

Maintainer edit: document OpenCode Zen and Go configuration, keep their registry entries with gateway providers, and add focused provider registration tests.

tests/providers/test_opencode_provider.py

@@ -0,0 +1,102 @@
+"""Tests for the OpenCode Zen and OpenCode Go provider registrations."""
+
+from nanobot.config.schema import Config, ProvidersConfig
+from nanobot.providers.openai_compat_provider import OpenAICompatProvider
+from nanobot.providers.registry import PROVIDERS, find_by_name
+
+
+def test_opencode_config_fields_exist() -> None:
+    config = ProvidersConfig()
+
+    assert hasattr(config, "opencode_zen")
+    assert hasattr(config, "opencode_go")
+
+
+def test_opencode_specs_use_openai_compatible_gateways() -> None:
+    specs = {spec.name: spec for spec in PROVIDERS}
+
+    zen = specs["opencode_zen"]
+    assert zen.backend == "openai_compat"
+    assert zen.env_key == "OPENCODE_API_KEY"
+    assert zen.display_name == "OpenCode Zen"
+    assert zen.is_gateway is True
+    assert zen.detect_by_base_keyword == "opencode.ai/zen"
+    assert zen.default_api_base == "https://opencode.ai/zen/v1"
+    assert "opencode" in zen.strip_model_prefixes
+
+    go = specs["opencode_go"]
+    assert go.backend == "openai_compat"
+    assert go.env_key == "OPENCODE_API_KEY"
+    assert go.display_name == "OpenCode Go"
+    assert go.is_gateway is True
+    assert go.detect_by_base_keyword == "opencode.ai/zen/go"
+    assert go.default_api_base == "https://opencode.ai/zen/go/v1"
+    assert "opencode-go" in go.strip_model_prefixes
+
+
+def test_find_by_name_opencode_providers() -> None:
+    zen = find_by_name("opencode_zen")
+    assert zen is not None
+    assert zen.name == "opencode_zen"
+
+    go = find_by_name("opencode-go")
+    assert go is not None
+    assert go.name == "opencode_go"
+
+
+def test_opencode_forced_providers_use_default_api_base() -> None:
+    zen_config = Config.model_validate(
+        {
+            "providers": {"opencodeZen": {"apiKey": "opencode-key"}},
+            "agents": {"defaults": {"provider": "opencode_zen", "model": "opencode/o3"}},
+        }
+    )
+
+    assert zen_config.get_provider_name() == "opencode_zen"
+    assert zen_config.get_api_key() == "opencode-key"
+    assert zen_config.get_api_base() == "https://opencode.ai/zen/v1"
+
+    go_config = Config.model_validate(
+        {
+            "providers": {"opencodeGo": {"apiKey": "opencode-key"}},
+            "agents": {"defaults": {"provider": "opencode_go", "model": "opencode-go/o3"}},
+        }
+    )
+
+    assert go_config.get_provider_name() == "opencode_go"
+    assert go_config.get_api_key() == "opencode-key"
+    assert go_config.get_api_base() == "https://opencode.ai/zen/go/v1"
+
+
+def test_opencode_prefixes_are_stripped_before_request() -> None:
+    zen_provider = OpenAICompatProvider(
+        api_key=None,
+        default_model="opencode/o3",
+        spec=find_by_name("opencode_zen"),
+    )
+    zen_kwargs = zen_provider._build_kwargs(
+        messages=[{"role": "user", "content": "hi"}],
+        tools=None,
+        model="opencode/o3",
+        max_tokens=1024,
+        temperature=0.7,
+        reasoning_effort=None,
+        tool_choice=None,
+    )
+    assert zen_kwargs["model"] == "o3"
+
+    go_provider = OpenAICompatProvider(
+        api_key=None,
+        default_model="opencode-go/o3",
+        spec=find_by_name("opencode_go"),
+    )
+    go_kwargs = go_provider._build_kwargs(
+        messages=[{"role": "user", "content": "hi"}],
+        tools=None,
+        model="opencode-go/o3",
+        max_tokens=1024,
+        temperature=0.7,
+        reasoning_effort=None,
+        tool_choice=None,
+    )
+    assert go_kwargs["model"] == "o3"