llmshim 0.7.2

Blazing fast LLM API translation layer in pure Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143

//! One bounded interpretation of upstream errors, shared by all HTTP surfaces.
use serde::Serialize;
use serde_json::Value;

#[derive(Debug, Clone, Serialize)]
pub(crate) struct NormalizedError {
    pub message: String,
    #[serde(rename = "type", skip_serializing_if = "Option::is_none")]
    pub kind: Option<String>,
    pub code: Value,
    pub param: Value,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub status: Option<u16>,
}

impl NormalizedError {
    pub fn public_code<'a>(&'a self, fallback: &'a str) -> &'a str {
        self.code
            .as_str()
            .filter(|code| !code.is_empty())
            .or(self.kind.as_deref())
            .unwrap_or(fallback)
    }

    pub fn code_type(&self) -> Option<&'static str> {
        match self.code.as_str() {
            Some("invalid_api_key" | "unauthorized" | "authentication_error") => {
                Some("authentication_error")
            }
            Some("permission_denied" | "permission_error") => Some("permission_error"),
            Some("insufficient_quota" | "rate_limit_exceeded" | "rate_limit_error") => {
                Some("rate_limit_error")
            }
            Some("model_not_found" | "not_found_error") => Some("not_found_error"),
            _ => None,
        }
    }
}

/// Decode recognized error envelopes and remove known internal Display prefixes.
/// Ordinary text and malformed envelopes are retained; neither is an error here.
pub(crate) fn normalize_error(message: &str) -> NormalizedError {
    let mut error = NormalizedError {
        message: message.into(),
        kind: None,
        code: Value::Null,
        param: Value::Null,
        status: None,
    };
    for _ in 0..4 {
        let mut candidate = error.message.as_str();
        for _ in 0..4 {
            if let Some(rest) = candidate
                .strip_prefix("upstream error: ")
                .or_else(|| candidate.strip_prefix("stream error: "))
            {
                candidate = rest;
            } else if let Some((status, body)) = candidate
                .strip_prefix("provider error (")
                .and_then(|rest| rest.split_once("): "))
                .and_then(|(status, body)| {
                    status
                        .parse::<u16>()
                        .ok()
                        .filter(|s| (100..=599).contains(s))
                        .map(|status| (status, body))
                })
            {
                error.status = Some(status);
                candidate = body;
            } else {
                break;
            }
        }
        error.message = candidate.to_owned();
        let Ok(value) = serde_json::from_str::<Value>(&error.message) else {
            break;
        };
        let Some(inner) = value.get("error").and_then(Value::as_object) else {
            break;
        };
        let Some(message) = inner.get("message").and_then(Value::as_str) else {
            break;
        };
        error.message = message.into();
        error.kind = inner
            .get("type")
            .and_then(Value::as_str)
            .filter(|s| !s.is_empty())
            .map(str::to_owned);
        error.code = inner.get("code").cloned().unwrap_or(Value::Null);
        error.param = inner.get("param").cloned().unwrap_or(Value::Null);
        if let Some(status) = inner
            .get("status")
            .and_then(Value::as_u64)
            .filter(|s| (100..=599).contains(s))
        {
            error.status = Some(status as u16);
        }
    }
    error
}

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

    #[test]
    fn shared_normalization_handles_plain_text_nested_envelopes_and_display_prefixes() {
        let text = "upstream error: provider error (401): Plain failure.";
        let error = normalize_error(text);
        assert_eq!(error.message, "Plain failure.");
        assert_eq!(error.status, Some(401));
        let inner = json!({"error":{"type":"authentication_error","code":"invalid_api_key","message":"Invalid key."}});
        let outer = json!({"error":{"message":inner.to_string()}});
        let error = normalize_error(&format!("stream error: {outer}"));
        assert_eq!(error.message, "Invalid key.");
        assert_eq!(error.kind.as_deref(), Some("authentication_error"));
        assert_eq!(error.public_code("provider_error"), "invalid_api_key");
        for text in [
            " ordinary text ",
            "{bad JSON",
            r#"{"error":{"message":null}}"#,
            r#"{"message":"not an envelope"}"#,
        ] {
            assert_eq!(normalize_error(text).message, text);
        }
    }

    #[test]
    fn nested_envelopes_have_a_fixed_unwrap_bound() {
        let mut message = "deep failure".to_owned();
        for _ in 0..5 {
            message = json!({"error":{"message":message}}).to_string();
        }
        let normalized = normalize_error(&message);
        assert_eq!(
            normalized.message,
            json!({"error":{"message":"deep failure"}}).to_string()
        );
    }
}