Reference: Usage as a lib #8

- Implement protocol versioning
- migrate to thisError
- general error handling improvements in socktop_connector lib
- improve documentation
- increment  version

socktop_connector/src/error.rs

@@ -0,0 +1,136 @@
+//! Error types for socktop_connector
+
+use thiserror::Error;
+
+/// Errors that can occur when using socktop_connector
+#[derive(Error, Debug)]
+pub enum ConnectorError {
+    /// WebSocket connection failed
+    #[error("WebSocket connection failed: {source}")]
+    ConnectionFailed {
+        #[from]
+        source: tokio_tungstenite::tungstenite::Error,
+    },
+
+    /// URL parsing error
+    #[error("Invalid URL: {url}")]
+    InvalidUrl {
+        url: String,
+        #[source]
+        source: url::ParseError,
+    },
+
+    /// TLS certificate error
+    #[error("TLS certificate error: {message}")]
+    TlsError {
+        message: String,
+        #[source]
+        source: Box<dyn std::error::Error + Send + Sync>,
+    },
+
+    /// Certificate file not found or invalid
+    #[error("Certificate file error at '{path}': {message}")]
+    CertificateError { path: String, message: String },
+
+    /// Invalid server response format
+    #[error("Invalid response from server: {message}")]
+    InvalidResponse { message: String },
+
+    /// JSON parsing error
+    #[error("JSON parsing error: {source}")]
+    JsonError {
+        #[from]
+        source: serde_json::Error,
+    },
+
+    /// Request/response protocol error
+    #[error("Protocol error: {message}")]
+    ProtocolError { message: String },
+
+    /// Connection is not established
+    #[error("Not connected to server")]
+    NotConnected,
+
+    /// Connection was closed unexpectedly
+    #[error("Connection closed: {reason}")]
+    ConnectionClosed { reason: String },
+
+    /// IO error (network, file system, etc.)
+    #[error("IO error: {source}")]
+    IoError {
+        #[from]
+        source: std::io::Error,
+    },
+
+    /// Compression/decompression error
+    #[error("Compression error: {message}")]
+    CompressionError { message: String },
+
+    /// Protocol Buffer parsing error
+    #[error("Protocol buffer error: {source}")]
+    ProtobufError {
+        #[from]
+        source: prost::DecodeError,
+    },
+}
+
+/// Result type alias for connector operations
+pub type Result<T> = std::result::Result<T, ConnectorError>;
+
+impl ConnectorError {
+    /// Create a TLS error with context
+    pub fn tls_error(
+        message: impl Into<String>,
+        source: impl std::error::Error + Send + Sync + 'static,
+    ) -> Self {
+        Self::TlsError {
+            message: message.into(),
+            source: Box::new(source),
+        }
+    }
+
+    /// Create a certificate error
+    pub fn certificate_error(path: impl Into<String>, message: impl Into<String>) -> Self {
+        Self::CertificateError {
+            path: path.into(),
+            message: message.into(),
+        }
+    }
+
+    /// Create a protocol error
+    pub fn protocol_error(message: impl Into<String>) -> Self {
+        Self::ProtocolError {
+            message: message.into(),
+        }
+    }
+
+    /// Create an invalid response error
+    pub fn invalid_response(message: impl Into<String>) -> Self {
+        Self::InvalidResponse {
+            message: message.into(),
+        }
+    }
+
+    /// Create a connection closed error
+    pub fn connection_closed(reason: impl Into<String>) -> Self {
+        Self::ConnectionClosed {
+            reason: reason.into(),
+        }
+    }
+
+    /// Create a compression error
+    pub fn compression_error(message: impl Into<String>) -> Self {
+        Self::CompressionError {
+            message: message.into(),
+        }
+    }
+}
+
+impl From<url::ParseError> for ConnectorError {
+    fn from(source: url::ParseError) -> Self {
+        Self::InvalidUrl {
+            url: "unknown".to_string(), // We don't have the URL in the error context
+            source,
+        }
+    }
+}