lc-providers 0.22.4

// lc-providers/src/error.rs
//! Unified error type for the lc-providers crate.
//!
//! Aggregates all provider-specific error types so the `?` operator works
//! seamlessly across provider boundaries.

pub use crate::ollama::OllamaError;
pub use crate::openai::responses::types::ResponsesError;
pub use crate::openai::AssistantError;
pub use crate::openai::OpenAIError;
pub use crate::providers::anthropic::error::AnthropicError;
pub use crate::providers::azure::AzureOpenAIError;
pub use crate::providers::cohere::CohereError;
pub use crate::providers::gemini::GeminiError;

/// Unified error type that aggregates all LLM provider errors.
///
/// This allows using `?` across provider boundaries without manually
/// mapping error types. Each variant wraps the original provider
/// error, preserving full context.
#[derive(Debug)]
#[non_exhaustive]
pub enum ProviderError {
    /// OpenAI API error.
    OpenAI(OpenAIError),
    /// Anthropic API error.
    Anthropic(AnthropicError),
    /// Gemini API error.
    Gemini(GeminiError),
    /// Azure OpenAI API error.
    Azure(AzureOpenAIError),
    /// Cohere API error.
    Cohere(CohereError),
    /// Ollama API error.
    Ollama(OllamaError),
    /// OpenAI Assistants API error.
    Assistant(AssistantError),
    /// OpenAI Responses API error.
    Responses(ResponsesError),
    /// DeepSeek API error (OpenAI-compatible endpoint).
    DeepSeek(OpenAIError),
    /// Qwen (Alibaba) API error (OpenAI-compatible endpoint).
    Qwen(OpenAIError),
    /// Moonshot (Kimi) API error (OpenAI-compatible endpoint).
    Moonshot(OpenAIError),
    /// Zhipu (ChatGLM) API error (OpenAI-compatible endpoint).
    Zhipu(OpenAIError),
    /// Mistral API error (OpenAI-compatible endpoint).
    Mistral(OpenAIError),
    /// B5: any OpenAI-compatible endpoint reached through the generic client
    /// (Groq, OpenRouter, xAI, vLLM, LM Studio, private gateways, …). The
    /// `provider` label identifies which preset or custom endpoint failed.
    OpenAICompatible {
        /// Endpoint label (`"groq"`, `"openrouter"`, `"xai"`, `"openai-compatible"`).
        provider: String,
        /// Underlying OpenAI-protocol error.
        source: OpenAIError,
    },
    /// Configuration error (missing/malformed environment variables, etc.).
    Config(String),
    /// Testkit harness error (recording/replay failures from `lc-testkit`).
    Testkit(String),
}

impl std::fmt::Display for ProviderError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            ProviderError::OpenAI(e) => write!(f, "OpenAI error: {e}"),
            ProviderError::Anthropic(e) => write!(f, "Anthropic error: {e}"),
            ProviderError::Gemini(e) => write!(f, "Gemini error: {e}"),
            ProviderError::Azure(e) => write!(f, "Azure OpenAI error: {e}"),
            ProviderError::Cohere(e) => write!(f, "Cohere error: {e}"),
            ProviderError::Ollama(e) => write!(f, "Ollama error: {e}"),
            ProviderError::Assistant(e) => write!(f, "Assistant error: {e}"),
            ProviderError::Responses(e) => write!(f, "Responses error: {e}"),
            ProviderError::DeepSeek(e) => write!(f, "DeepSeek error: {e}"),
            ProviderError::Qwen(e) => write!(f, "Qwen error: {e}"),
            ProviderError::Moonshot(e) => write!(f, "Moonshot error: {e}"),
            ProviderError::Zhipu(e) => write!(f, "Zhipu error: {e}"),
            ProviderError::Mistral(e) => write!(f, "Mistral error: {e}"),
            ProviderError::OpenAICompatible { provider, source } => {
                write!(f, "{provider} (OpenAI-compatible) error: {source}")
            }
            ProviderError::Config(msg) => write!(f, "Configuration error: {msg}"),
            ProviderError::Testkit(msg) => write!(f, "Testkit error: {msg}"),
        }
    }
}

impl std::error::Error for ProviderError {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        match self {
            ProviderError::OpenAI(e) => Some(e),
            ProviderError::Anthropic(e) => Some(e),
            ProviderError::Gemini(e) => Some(e),
            ProviderError::Azure(e) => Some(e),
            ProviderError::Cohere(e) => Some(e),
            ProviderError::Ollama(e) => Some(e),
            ProviderError::Assistant(e) => Some(e),
            ProviderError::Responses(e) => Some(e),
            ProviderError::DeepSeek(e) => Some(e),
            ProviderError::Qwen(e) => Some(e),
            ProviderError::Moonshot(e) => Some(e),
            ProviderError::Zhipu(e) => Some(e),
            ProviderError::Mistral(e) => Some(e),
            ProviderError::OpenAICompatible { source, .. } => Some(source),
            ProviderError::Config(_) => None,
            ProviderError::Testkit(_) => None,
        }
    }
}

// ---- From impls for all provider error types ----

impl From<OpenAIError> for ProviderError {
    fn from(e: OpenAIError) -> Self {
        ProviderError::OpenAI(e)
    }
}
impl From<AnthropicError> for ProviderError {
    fn from(e: AnthropicError) -> Self {
        ProviderError::Anthropic(e)
    }
}
impl From<GeminiError> for ProviderError {
    fn from(e: GeminiError) -> Self {
        ProviderError::Gemini(e)
    }
}
impl From<OllamaError> for ProviderError {
    fn from(e: OllamaError) -> Self {
        ProviderError::Ollama(e)
    }
}
impl From<AssistantError> for ProviderError {
    fn from(e: AssistantError) -> Self {
        ProviderError::Assistant(e)
    }
}
impl From<ResponsesError> for ProviderError {
    fn from(e: ResponsesError) -> Self {
        ProviderError::Responses(e)
    }
}
impl From<AzureOpenAIError> for ProviderError {
    fn from(e: AzureOpenAIError) -> Self {
        ProviderError::Azure(e)
    }
}
impl From<CohereError> for ProviderError {
    fn from(e: CohereError) -> Self {
        ProviderError::Cohere(e)
    }
}

/// Allow testkit harness errors (recording/replay) to surface through the
/// provider error chain. `lc-testkit` is an external crate and cannot
/// construct `#[non_exhaustive]` variants, so this is the sole entry point.
impl From<String> for ProviderError {
    fn from(msg: String) -> Self {
        ProviderError::Testkit(msg)
    }
}

// ---- LCEL Error conversion ----

/// Allow `ProviderError` to convert into `LcelError` for LCEL pipeline compatibility.
/// This enables LLM providers to participate in `pipe()` chains.
impl From<ProviderError> for lc_core::LcelError {
    fn from(err: ProviderError) -> Self {
        lc_core::LcelError::Provider(err.to_string())
    }
}

/// Allow `OpenAIError` to convert into `LcelError` for LCEL pipeline compatibility.
///
/// `OpenAIChat`'s `Runnable` uses `OpenAIError` directly as its `Error` type; without the
/// bridge, `OpenAIChat` cannot enter a `pipe()` chain (which needs `R2::Error: Into<LcelError>`).
/// Qwen / DeepSeek go through OpenAI-compatible endpoints, but they wrap `OpenAIError` into
/// `ProviderError` and bridge from there, already covered by the impl above.
impl From<OpenAIError> for lc_core::LcelError {
    fn from(err: OpenAIError) -> Self {
        lc_core::LcelError::Provider(err.to_string())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    /// Native OpenAIChat errors convert cleanly into LcelError, so `openai.pipe(...)` compiles as the second pipe step.
    #[test]
    fn openai_error_into_lcel_error() {
        let e = OpenAIError::Api("rate limited".to_string());
        let lcel: lc_core::LcelError = e.into();
        assert!(matches!(
            lcel,
            lc_core::LcelError::Provider(ref msg) if msg.contains("API error: rate limited")
        ));
    }

    /// Qwen/DeepSeek reuse OpenAIError, but bridge through ProviderError, equally into LcelError.
    #[test]
    fn qwen_provider_error_into_lcel_error() {
        let e = ProviderError::Qwen(OpenAIError::Http("timeout".to_string()));
        let lcel: lc_core::LcelError = e.into();
        assert!(matches!(
            lcel,
            lc_core::LcelError::Provider(ref msg) if msg.contains("Qwen error") && msg.contains("timeout")
        ));
    }

    #[test]
    fn deepseek_provider_error_into_lcel_error() {
        let e = ProviderError::DeepSeek(OpenAIError::Parse("bad json".to_string()));
        let lcel: lc_core::LcelError = e.into();
        assert!(matches!(
            lcel,
            lc_core::LcelError::Provider(ref msg) if msg.contains("DeepSeek error")
        ));
    }

    /// B5: generic OpenAI-compatible errors carry the preset label and source.
    #[test]
    fn openai_compatible_error_label_and_source() {
        let e = ProviderError::OpenAICompatible {
            provider: "groq".to_string(),
            source: OpenAIError::Api("HTTP 429: slow down".to_string()),
        };
        let text = e.to_string();
        assert!(text.contains("groq"), "{text}");
        assert!(text.contains("OpenAI-compatible"), "{text}");
        assert!(text.contains("429"), "{text}");
        assert!(std::error::Error::source(&e).is_some());

        let lcel: lc_core::LcelError = e.into();
        assert!(matches!(
            lcel,
            lc_core::LcelError::Provider(ref msg) if msg.contains("groq")
        ));
    }
}