keel_cli/scan/

mod.rs

//! Static scanning — the first of the three evidence sources behind `keel init`
//! and `keel doctor` (dx-spec §2). No code runs: we read the project's source
//! and find where effects enter.
//!
//! Two scanners, one merged result:
//! - [`python`] shells an `ast`-walker out to `python3 -` for precise Python
//!   parsing (imports of known effect libraries, URL/DSN string literals).
//! - [`js`] parses JS/TS/JSX in-process with oxc (no Node toolchain needed)
//!   for `fetch`/`undici`/`node:http` usage, provider-SDK imports, effect-lib
//!   call sites, and URL literals.
//!
//! Both label every finding with `file:line`, so the generated `keel.toml` can
//! cite where each target was found and trust stays inspectable.

pub mod js;
pub mod python;

use std::collections::{BTreeMap, BTreeSet};
use std::path::Path;

/// What kind of target a sighting resolves to. Governs the policy block
/// `keel init` writes (an `llm:*` target gets the LLM pack; a host gets the
/// outbound pack).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum TargetClass {
    /// A network host, e.g. `api.stripe.com` — from a URL/DSN literal.
    Host,
    /// A semantic `llm:<provider>` target — from a provider SDK import.
    Llm,
}

/// One effect call site with enclosing-function attribution — an internal
/// detail of the JS/TS pass ([`js`]), which uses it to verify its real
/// scope-chain tracking (dotted paths like `Class.method`) independently of
/// the coarser top-level-only [`FunctionFacts`] attribution `keel flows
/// suggest` consumes. Not exposed on [`ScanResult`]. Field order is the sort
/// order (file, then line).
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct CallSite {
    /// Project-relative path with `/` separators.
    pub file: String,
    /// 1-based line of the call expression.
    pub line: u32,
    /// What is called, rooted at the effect library where the receiver is
    /// known (`fetch`, `undici.request`, `openai.chat.completions.create`).
    pub callee: String,
    /// Dotted enclosing-scope path (`Class.method`, `outer.inner`), or `None`
    /// at module top level. Anonymous scopes inherit the nearest named scope.
    pub function: Option<String>,
}

/// One place a target was seen: a project-relative path and 1-based line.
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct Sighting {
    /// Project-relative path with `/` separators.
    pub file: String,
    /// 1-based line number.
    pub line: u32,
}

impl Sighting {
    /// Render as the `file:line` token used in evidence comments.
    pub fn label(&self) -> String {
        format!("{}:{}", self.file, self.line)
    }
}

/// A target and everywhere the static scan saw it, deduplicated and ordered.
#[derive(Debug, Clone)]
pub struct TargetEvidence {
    /// The target's class.
    pub class: TargetClass,
    /// Sorted, unique sightings.
    pub sightings: BTreeSet<Sighting>,
}

/// Per-function effect attribution — the evidence behind `keel flows suggest`.
///
/// Each language pass attributes what it finds *inside* a function definition
/// to that function: intercepted-effect call sites, calls that read time or
/// randomness (virtualized under Tier 2 replay), and constructs that defeat
/// replay outright (threads, subprocesses, raw sockets). Both passes
/// attribute by real containment: the Python walker via `ast` module-level
/// def bodies, the JS/TS pass via a real oxc scope walk (see [`js`]) — an
/// entry opens only for a function bound directly at module top level; class
/// methods and nested/inner functions roll up into the enclosing top-level
/// entry rather than opening their own.
#[derive(Debug, Clone, Default, PartialEq, Eq)]
pub struct FunctionFacts {
    /// The full flow-entrypoint ref this function would be designated as —
    /// `py:pipeline.ingest:main` or `ts:jobs/nightly.ts#run` (the `ts:`
    /// namespace covers all JS/TS files).
    pub entrypoint: String,
    /// Project-relative path of the defining file.
    pub file: String,
    /// 1-based line of the `def`/`function`.
    pub line: u32,
    /// Intercepted-effect call sites (HTTP / LLM / DSN-bearing libraries).
    pub effects: u32,
    /// Effect calls that are not idempotent-safe to re-send (POST/PATCH-shaped)
    /// and carry no idempotency evidence.
    pub idempotent_unsafe: u32,
    /// Wall-clock reads (`time.time`, `datetime.now`, `Date.now`, …) — these
    /// are virtualized (journaled + replayed) under Tier 2.
    pub time_reads: u32,
    /// Randomness reads (`random.*`, `uuid4`, `Math.random`, …) — also
    /// virtualized under Tier 2.
    pub random_reads: u32,
    /// Why replay would be unsafe (empty = the replay-safe estimate holds).
    /// Each reason cites `what at file:line`; sorted, deterministic.
    pub unsafe_reasons: Vec<String>,
    /// Targets referenced inside the function (hosts from URL literals,
    /// `llm:<provider>` from SDK calls) — the join key into `.keel/discovery.db`.
    pub targets: BTreeSet<String>,
}

/// The merged output of both scanners.
#[derive(Debug, Clone, Default)]
pub struct ScanResult {
    /// Number of source files parsed (Python + JS/TS) — the header's "N static
    /// scans".
    pub files_scanned: usize,
    /// Whether `python3` was available for the Python pass. When false, Python
    /// files could not be scanned; `keel init` notes this on stderr rather than
    /// letting it silently narrow coverage.
    pub python_available: bool,
    /// Discovered targets, keyed by target string, ordered.
    pub targets: BTreeMap<String, TargetEvidence>,
    /// Effect-library names detected across the project (e.g. `httpx`,
    /// `openai`, `boto3`, `fetch`). `keel doctor` cross-references these against
    /// its adapter registry to classify coverage.
    pub libs: BTreeSet<String>,
    /// Per-function attribution (see [`FunctionFacts`]), sorted by
    /// `(file, line)` — deterministic across runs.
    pub functions: Vec<FunctionFacts>,
}

impl ScanResult {
    fn add(&mut self, target: String, class: TargetClass, file: String, line: u32) {
        self.targets
            .entry(target)
            .or_insert_with(|| TargetEvidence {
                class,
                sightings: BTreeSet::new(),
            })
            .sightings
            .insert(Sighting { file, line });
    }
}

/// Scan `project` with both scanners and merge. Host targets are only emitted
/// when the language pass also saw an HTTP client in use (a bare URL in a
/// non-networked file is not evidence of an outbound call), keeping the output
/// honest.
pub fn scan(project: &Path) -> ScanResult {
    let mut result = ScanResult::default();

    let py = python::scan(project);
    result.python_available = py.available;
    result.files_scanned += py.files_scanned;
    merge_lang(&mut result, &py.findings);
    result.functions.extend(py.functions);

    let js = js::scan(project);
    result.files_scanned += js.files_scanned;
    merge_lang(&mut result, &js.findings);
    result.functions.extend(js.functions);

    result
        .functions
        .sort_by(|a, b| (&a.file, a.line, &a.entrypoint).cmp(&(&b.file, b.line, &b.entrypoint)));
    result
}

/// One language scanner's raw findings before host-gating.
#[derive(Debug, Clone, Default)]
pub struct LangFindings {
    /// Provider SDK imports → `llm:*` targets.
    pub llm: Vec<(String, Sighting)>,
    /// URL/DSN host literals → host targets (gated on `http_in_use`).
    pub hosts: Vec<(String, Sighting)>,
    /// Whether an HTTP client (http lib / fetch / undici) was seen at all.
    pub http_in_use: bool,
    /// Effect-library names detected (for `keel doctor`'s registry cross-check).
    pub libs: BTreeSet<String>,
    /// Effect call sites with enclosing-function attribution.
    pub call_sites: Vec<CallSite>,
}

fn merge_lang(result: &mut ScanResult, f: &LangFindings) {
    for (provider, s) in &f.llm {
        result.add(
            format!("llm:{provider}"),
            TargetClass::Llm,
            s.file.clone(),
            s.line,
        );
    }
    if f.http_in_use {
        for (host, s) in &f.hosts {
            result.add(host.clone(), TargetClass::Host, s.file.clone(), s.line);
        }
    }
    for lib in &f.libs {
        result.libs.insert(lib.clone());
    }
}

/// Directory names never descended into during a scan.
pub(crate) const SKIP_DIRS: &[&str] = &[
    ".keel",
    ".git",
    "__pycache__",
    "node_modules",
    ".venv",
    "venv",
    ".mypy_cache",
    ".pytest_cache",
    "dist",
    "build",
    "target",
];

/// Extract the host from a `scheme://host[:port][/…]` literal, lowercased and
/// without port/userinfo/path. Returns `None` for non-URL strings. Shared by
/// both scanners so Python and JS agree on what a host is.
pub(crate) fn host_from_url(s: &str) -> Option<String> {
    let s = s.trim();
    let (scheme, rest) = s.split_once("://")?;
    if scheme.is_empty()
        || !scheme
            .chars()
            .all(|c| c.is_ascii_alphanumeric() || matches!(c, '+' | '.' | '-'))
        || !scheme
            .chars()
            .next()
            .is_some_and(|c| c.is_ascii_alphabetic())
    {
        return None;
    }
    // authority ends at the first '/', '?', or '#'.
    let authority = rest.split(['/', '?', '#']).next().unwrap_or(rest);
    // strip userinfo, then port.
    let host_port = authority.rsplit('@').next().unwrap_or(authority);
    let host = host_port.split(':').next().unwrap_or(host_port);
    if host.is_empty() || host.contains(|c: char| c.is_whitespace()) {
        return None;
    }
    Some(host.to_ascii_lowercase())
}

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

    #[test]
    fn host_extraction_strips_port_userinfo_and_path() {
        assert_eq!(
            host_from_url("https://api.stripe.com/v1/x").as_deref(),
            Some("api.stripe.com")
        );
        assert_eq!(
            host_from_url("postgres://u:p@db.internal:5432/app").as_deref(),
            Some("db.internal")
        );
        assert_eq!(host_from_url("HTTPS://API.X").as_deref(), Some("api.x"));
        assert_eq!(host_from_url("not a url"), None);
        assert_eq!(host_from_url("://nohost"), None);
        assert_eq!(host_from_url("1bad://x"), None);
    }
}