mcp_postgres/
validation.rs

1use crate::errors::MCPError;
2
3const MAX_IDENTIFIER_LEN: usize = 255;
4
5pub fn validate_identifier(name: &str, label: &str) -> Result<(), MCPError> {
6    if name.is_empty() {
7        return Err(MCPError::InvalidParams(format!("'{label}' must not be empty")));
8    }
9    if name.len() > MAX_IDENTIFIER_LEN {
10        return Err(MCPError::InvalidParams(
11            format!("'{label}' exceeds maximum length of {MAX_IDENTIFIER_LEN} characters (got {})", name.len())
12        ));
13    }
14    for ch in name.chars() {
15        if !ch.is_alphanumeric() && ch != '_' {
16            return Err(MCPError::InvalidParams(
17                format!("'{label}' contains invalid character '{ch}' — only alphanumeric and underscore allowed")
18            ));
19        }
20    }
21    if name.starts_with(|c: char| c.is_ascii_digit()) {
22        return Err(MCPError::InvalidParams(
23            format!("'{label}' must not start with a digit")
24        ));
25    }
26    Ok(())
27}
28
29pub fn quote_identifier(name: &str) -> String {
30    format!("\"{}\"", name)
31}
32
33#[cfg(test)]
34mod tests {
35    use super::*;
36
37    #[test]
38    fn test_valid_identifier() {
39        assert!(validate_identifier("users", "table").is_ok());
40        assert!(validate_identifier("user_orders_2024", "table").is_ok());
41    }
42
43    #[test]
44    fn test_empty_identifier() {
45        let err = validate_identifier("", "table").unwrap_err();
46        assert!(err.to_string().contains("must not be empty"));
47    }
48
49    #[test]
50    fn test_too_long_identifier() {
51        let long = "a".repeat(256);
52        let err = validate_identifier(&long, "table").unwrap_err();
53        assert!(err.to_string().contains("exceeds maximum length"));
54    }
55
56    #[test]
57    fn test_invalid_char_identifier() {
58        let err = validate_identifier("users; DROP TABLE", "table").unwrap_err();
59        assert!(err.to_string().contains("invalid character"));
60    }
61
62    #[test]
63    fn test_digit_start_identifier() {
64        let err = validate_identifier("1users", "table").unwrap_err();
65        assert!(err.to_string().contains("must not start with a digit"));
66    }
67
68    #[test]
69    fn test_quote_identifier() {
70        assert_eq!(quote_identifier("users"), "\"users\"");
71        assert_eq!(quote_identifier("order_items"), "\"order_items\"");
72    }
73}
mcp_postgres/validation.rs

mcp_postgres/
validation.rs
