core-agent-ide/codex-rs/execpolicy/src/rule.rs

147 lines
4 KiB
Rust

use crate::decision::Decision;
use crate::error::Error;
use crate::error::Result;
use serde::Deserialize;
use serde::Serialize;
use shlex::try_join;
use std::any::Any;
use std::fmt::Debug;
use std::sync::Arc;
/// Matches a single command token, either a fixed string or one of several allowed alternatives.
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum PatternToken {
Single(String),
Alts(Vec<String>),
}
impl PatternToken {
fn matches(&self, token: &str) -> bool {
match self {
Self::Single(expected) => expected == token,
Self::Alts(alternatives) => alternatives.iter().any(|alt| alt == token),
}
}
pub fn alternatives(&self) -> &[String] {
match self {
Self::Single(expected) => std::slice::from_ref(expected),
Self::Alts(alternatives) => alternatives,
}
}
}
/// Prefix matcher for commands with support for alternative match tokens.
/// First token is fixed since we key by the first token in policy.
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct PrefixPattern {
pub first: Arc<str>,
pub rest: Arc<[PatternToken]>,
}
impl PrefixPattern {
pub fn matches_prefix(&self, cmd: &[String]) -> Option<Vec<String>> {
let pattern_length = self.rest.len() + 1;
if cmd.len() < pattern_length || cmd[0] != self.first.as_ref() {
return None;
}
for (pattern_token, cmd_token) in self.rest.iter().zip(&cmd[1..pattern_length]) {
if !pattern_token.matches(cmd_token) {
return None;
}
}
Some(cmd[..pattern_length].to_vec())
}
}
#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum RuleMatch {
PrefixRuleMatch {
#[serde(rename = "matchedPrefix")]
matched_prefix: Vec<String>,
decision: Decision,
},
}
impl RuleMatch {
pub fn decision(&self) -> Decision {
match self {
Self::PrefixRuleMatch { decision, .. } => *decision,
}
}
}
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct PrefixRule {
pub pattern: PrefixPattern,
pub decision: Decision,
}
pub trait Rule: Any + Debug + Send + Sync {
fn program(&self) -> &str;
fn matches(&self, cmd: &[String]) -> Option<RuleMatch>;
}
pub type RuleRef = Arc<dyn Rule>;
impl Rule for PrefixRule {
fn program(&self) -> &str {
self.pattern.first.as_ref()
}
fn matches(&self, cmd: &[String]) -> Option<RuleMatch> {
self.pattern
.matches_prefix(cmd)
.map(|matched_prefix| RuleMatch::PrefixRuleMatch {
matched_prefix,
decision: self.decision,
})
}
}
/// Count how many rules match each provided example and error if any example is unmatched.
pub(crate) fn validate_match_examples(rules: &[RuleRef], matches: &[Vec<String>]) -> Result<()> {
let mut unmatched_examples = Vec::new();
for example in matches {
if rules.iter().any(|rule| rule.matches(example).is_some()) {
continue;
}
unmatched_examples.push(
try_join(example.iter().map(String::as_str))
.unwrap_or_else(|_| "unable to render example".to_string()),
);
}
if unmatched_examples.is_empty() {
Ok(())
} else {
Err(Error::ExampleDidNotMatch {
rules: rules.iter().map(|rule| format!("{rule:?}")).collect(),
examples: unmatched_examples,
})
}
}
/// Ensure that no rule matches any provided negative example.
pub(crate) fn validate_not_match_examples(
rules: &[RuleRef],
not_matches: &[Vec<String>],
) -> Result<()> {
for example in not_matches {
if let Some(rule) = rules.iter().find(|rule| rule.matches(example).is_some()) {
return Err(Error::ExampleDidMatch {
rule: format!("{rule:?}"),
example: try_join(example.iter().map(String::as_str))
.unwrap_or_else(|_| "unable to render example".to_string()),
});
}
}
Ok(())
}