AI Slop Code Risk Monitor

dtolnay/syn

Name: dtolnay/syn — Rust Code Quality & Security Review | AI Slop Code Risk Monitor
Creator: AI Slop Code Risk Monitor

Adjusted legacy signal; badge bands: 25 / 50 / 75 (different from dashboard bands).

Parser for Rust source code

3.5 Low pattern signal View on GitHub

Open-Source Code Quality, Security and Technical Debt Review

This report summarizes scanner evidence for dtolnay/syn, a Rust project with 3,437 GitHub stars. SynthScan examined 79,026 lines of code across 161 source files, recording 304 pattern matches distributed across 1 syntactic category. The legacy adjusted pattern signal is 3.5 (Low pattern signal); it is not an authorship estimate.

Use the findings to ask whether maintainers can explain intent, verify dependencies, simplify unnecessary scaffolding, and focus review effort. Risk Payload v1 adds ownership, supply-chain, over-engineering, and review-effort vectors when available. These are prompts for human verification, not probabilities, security findings, or measured maintenance costs.

3.5

Adjusted Signal

3.5

Raw Pattern Score

100%

Time Factor

2026-10-30

Last Push

3.4K

Stars

Rust

Language

79.0K

Lines of Code

161

Files

304

Pattern Hits

2026-10-31

Scan Date

0.00

HC Hit Rate

Risk Review · Payload v1

Use each vector to guide manual verification of the underlying findings.

Payload schema: 1.0.0 · Engine: 2.0.0 · Scoring: heuristic-density-v1 · Scan date: 2026-10-31.

Cognitive Ownership Risk 16.1/100 · LOW

Can maintainers explain intent, assumptions, and trade-offs? 304 finding(s).

Hallucinated Dependency & Supply Chain Risk 0.0/100 · LOW

Are imports declared and package/API names verified? 0 finding(s).

Agent Over-Engineering Ratio 0.0/100 · LOW

Are wrappers, guards, and repeated structures necessary? 0 finding(s).

PR Review Velocity Impact 17.5/100 · LOW

Which changes need focused human review? 304 finding(s).

What These Metrics Mean

Adjusted Signal: Legacy pattern score normalized per 1,000 scanned lines and multiplied by the repository-level time factor. It is not an estimate of AI authorship.
Raw Pattern Score: Sum of severity- and context-weighted pattern findings before applying the time factor.
Time Factor: A coarse multiplier based on repository last-push metadata. It does not identify when individual code was written.
Pattern Hits: Count of configured pattern findings. Review each location and surrounding code before acting.
HC Hit Rate: High- and critical-severity findings per scanned file. Severity is a configured detector weight, not proof of a vulnerability or authorship.
Lines / Files: Scan coverage denominators used by the legacy normalized score.

Pattern-Signal History

This chart tracks the legacy adjusted pattern score across scan runs. Changes can reflect source changes, scan coverage, or detector/scoring versions; they do not measure AI adoption or prove that a team refactored code. Compare runs only when their scoring versions are compatible. The dashed line tracks the raw pattern-hit count.

Severity Breakdown

Groups findings by configured severity weight. Severity is not a confidence estimate, security rating, or proof that a package is missing. Verify imports against the project's manifests and inspect each finding in its local design context.

CRITICAL 0HIGH 0MEDIUM 0LOW 304

Directory Score Breakdown

This horizontal bar chart shows where configured pattern scores accumulate across directories. Treat the bars as locations to inspect, not as evidence of authorship or code quality. Use the file-level findings to decide whether a directory needs a focused ownership, dependency, complexity, or review check.

Pattern Findings

The scanner identified 304 distinct pattern matches across 1 syntactic category. Each entry below represents a discrete location in the source code where the engine recorded a detector match to inspect in context. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.

Reading the findings table: The Severity column indicates the configured finding weight (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — legacy comment-context matches receive a ×1.5 score weight. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier under the legacy scoring model.

Over-Commented Block304 hits · 278 pts

Severity	File	Line	Snippet	Context
LOW	tests/test_precedence.rs	1	// This test does the following for every file in the rust-lang/rust repo:	COMMENT
LOW	tests/test_expr.rs	1001	}));	COMMENT
LOW	codegen/src/main.rs	1	// This crate crawls the Syn source directory to find all structs and enums that	COMMENT
LOW	json/src/lib.rs	1	//! # Data structures that describe Syn's syntax tree.	COMMENT
LOW	json/src/lib.rs	21	//! every Syn release comes with a machine-readable description of that version	COMMENT
LOW	json/src/lib.rs	41	//! for node in &defs.types {	COMMENT
LOW	json/src/lib.rs	61	/// The Syn version whose syntax tree is described by this data.	COMMENT
LOW	json/src/lib.rs	121	}	COMMENT
LOW	json/src/lib.rs	141	serde(rename_all = "lowercase")	COMMENT
LOW	json/src/lib.rs	161		COMMENT
LOW	examples/lazy-static/lazy-static/src/lib.rs	1	#![feature(proc_macro_diagnostic)]	COMMENT
LOW	examples/lazy-static/lazy-static/src/lib.rs	81	init.span()	COMMENT
LOW	examples/dump-syntax/src/main.rs	1	//! Parse a Rust source file into a `syn::File` and print out a debug	COMMENT
LOW	examples/trace-var/trace-var/src/lib.rs	61	///	COMMENT
LOW	examples/trace-var/trace-var/src/lib.rs	161	/// Attribute to print the value of the given variables each time they are	COMMENT
LOW	src/lit.rs	21	use proc_macro2::{TokenStream, TokenTree};	COMMENT
LOW	src/lit.rs	161	///	COMMENT
LOW	src/lit.rs	181	/// }	COMMENT
LOW	src/lit.rs	201	/// ```	COMMENT
LOW	src/lit.rs	441		COMMENT
LOW	src/custom_keyword.rs	1	/// Define a type that supports parsing and printing a given identifier as if it	COMMENT
LOW	src/custom_keyword.rs	21	/// - [Parsing] — `input.parse::<kw::whatever>()?`	COMMENT
LOW	src/custom_keyword.rs	41	/// The symbols `bool` and `str` are not reserved keywords in Rust so these are	COMMENT
LOW	src/custom_keyword.rs	61	/// Str {	COMMENT
LOW	src/custom_keyword.rs	81	/// value: input.parse()?,	COMMENT
LOW	src/punctuated.rs	1	//! A punctuated sequence of syntax tree nodes separated by punctuation.	COMMENT
LOW	src/punctuated.rs	161	/// punctuated pairs.	COMMENT
LOW	src/punctuated.rs	321	#[cfg(feature = "parsing")]	COMMENT
LOW	src/punctuated.rs	1021	Pair::Punctuated(_, p) => Some(p),	COMMENT
LOW	src/custom_punctuation.rs	1	/// Define a type that supports parsing and printing a multi-character symbol	COMMENT
LOW	src/custom_punctuation.rs	21	/// - Construction from multiple [`Span`] — `let lrarrow = LeftRightArrow([sp, sp, sp])`	COMMENT
LOW	src/custom_punctuation.rs	41	/// // expr </> expr </> expr ...	COMMENT
LOW	src/custom_punctuation.rs	61	/// }	COMMENT
LOW	src/stmt.rs	61	///	COMMENT
LOW	src/stmt.rs	141	///	COMMENT
LOW	src/stmt.rs	161	/// }	COMMENT
LOW	src/error.rs	21	pub type Result<T> = core::result::Result<T, Error>;	COMMENT
LOW	src/error.rs	41	/// #	COMMENT
LOW	src/error.rs	61	/// }	COMMENT
LOW	src/error.rs	81	/// # extern crate proc_macro;	COMMENT
LOW	src/error.rs	101	/// #	COMMENT
LOW	src/error.rs	141	///	COMMENT
LOW	src/error.rs	181	/// Creates an error with the specified message spanning the given syntax	COMMENT
LOW	src/error.rs	221	/// use syn::parse::{Error, ParseStream, Result};	COMMENT
LOW	src/error.rs	241	/// }	COMMENT
LOW	src/error.rs	301		COMMENT
LOW	src/error.rs	321	/// # Example	COMMENT
LOW	src/token.rs	1	//! Tokens representing Rust punctuation, keywords, and delimiters.	COMMENT
LOW	src/token.rs	21	//! pub static_token: Token![static],	COMMENT
LOW	src/token.rs	41	//! [`braced!`]: crate::braced!	COMMENT
LOW	src/token.rs	61	//! ty: input.parse()?,	COMMENT
LOW	src/token.rs	81	//!	COMMENT
LOW	src/token.rs	821	/// use syn::{Ident, Token};	COMMENT
LOW	src/token.rs	841	/// As an expression, `Token!` is used for peeking tokens or instantiating	COMMENT
LOW	src/token.rs	861	/// let span = name.span();	COMMENT
LOW	src/parse_macro_input.rs	1	/// Parse the input TokenStream of a macro, triggering a compile error if the	COMMENT
LOW	src/parse_macro_input.rs	21	/// use proc_macro::TokenStream;	COMMENT
LOW	src/parse_macro_input.rs	41	///	COMMENT
LOW	src/parse_macro_input.rs	61	/// # use syn::parse::ParseStream;	COMMENT
LOW	src/parse_macro_input.rs	81	/// ```	COMMENT
244 more matches not shown…