Rust reflection, serialization, deserialization, pretty printing, etc. — the last proc macro you should need
This report summarizes scanner evidence for facet-rs/facet, a Rust project with 2,588 GitHub stars. SynthScan examined 129,519 lines of code across 533 source files, recording 573 pattern matches distributed across 10 syntactic categories. The legacy adjusted pattern signal is 5.1 (Moderate 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.
Use each vector to guide manual verification of the underlying findings.
Can maintainers explain intent, assumptions, and trade-offs? 540 finding(s).
Are imports declared and package/API names verified? 9 finding(s).
Are wrappers, guards, and repeated structures necessary? 24 finding(s).
Which changes need focused human review? 573 finding(s).
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.
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.
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.
The scanner identified 573 distinct pattern matches across 10 syntactic categories. 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.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | .config/nextest.toml | 41 | # Run tests under valgrind with leak checking | COMMENT |
| LOW | facet-pretty/src/color.rs | 1 | //! Color palettes and terminal theme detection for pretty-printing. | COMMENT |
| LOW | facet-pretty/src/color.rs | 101 | /// | COMMENT |
| LOW | facet-pretty/src/lib.rs | 1 | #![warn(missing_docs)] | COMMENT |
| LOW | facet-pretty/src/lib.rs | 21 | //! name: String, | COMMENT |
| LOW | facet-pretty/src/printer.rs | 21 | use crate::color::ColorGenerator; | COMMENT |
| LOW | facet-pretty/src/printer.rs | 41 | /// Background (#1a1b26) | COMMENT |
| LOW | facet-pretty/src/printer.rs | 81 | // ======================================================================== | COMMENT |
| LOW | facet-macros-impl/src/derive.rs | 1 | use crate::{ToTokens, *}; | COMMENT |
| LOW | facet-macros-impl/src/on_error.rs | 1 | use crate::{Delimiter, Group, Ident, Span, TokenStream, TokenTree}; | COMMENT |
| LOW | facet-macros-impl/src/lib.rs | 1 | // unsynn's Parser API intentionally returns its large Error by value. | COMMENT |
| LOW | facet-macros-impl/src/lib.rs | 41 | mod process_struct; | COMMENT |
| LOW | facet-macros-impl/src/extension.rs | 81 | } else { | COMMENT |
| LOW | facet-macros-impl/src/extension.rs | 121 | } | COMMENT |
| LOW | facet-macros-impl/src/plugin.rs | 1 | //! Plugin system for facet derive macro. | COMMENT |
| LOW | facet-macros-impl/src/plugin.rs | 201 | /// This filters out the plugin-system-specific attributes before passing | COMMENT |
| LOW | facet-macros-impl/src/plugin.rs | 1321 | } | COMMENT |
| LOW | facet-macros-impl/src/process_enum.rs | 1401 | #[automatically_derived] | COMMENT |
| LOW | facet-macros-impl/src/process_enum.rs | 1421 | #attributes_call | COMMENT |
| LOW | facet-macros-impl/src/process_struct.rs | 1 | //! Struct processing and vtable generation for the Facet derive macro. | COMMENT |
| LOW | facet-macros-impl/src/process_struct.rs | 21 | //! | COMMENT |
| LOW | facet-macros-impl/src/process_struct.rs | 41 | COMMENT | |
| LOW | facet-macros-impl/src/process_struct.rs | 181 | }); | COMMENT |
| LOW | facet-macros-impl/src/process_struct.rs | 481 | // Uses prelude aliases for compact output (𝟋VtE, 𝟋VtD) | COMMENT |
| LOW | facet-macros-impl/src/process_struct.rs | 2581 | // Proxy inherent impl (outside the Facet impl so generic params are in scope) | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/mod.rs | 1 | //! Attribute grammar system for declarative extension attribute parsing. | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/dispatch_attr.rs | 781 | // No value: for Option types, return None; otherwise error | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/dispatch_attr.rs | 901 | return quote_spanned! { span => | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/dispatch_attr.rs | 981 | /// A single type in a `list(shape_type)` payload - everything up to the next | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/dispatch_attr.rs | 1001 | /// items: | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 61 | COMMENT | |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 281 | #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)] | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 341 | /// If true, generate `<$ty as ::core::default::Default>::default()` when no value provided. | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 361 | /// A comma-separated list of types, each converted to a Shape reference. | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 581 | } | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 941 | // For builtin mode, skip deriving Facet entirely because the derive macro | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 1241 | @variants { #(#variants_meta),* } | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 1261 | // fn is_empty(s: &String) -> bool { ... } | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 1321 | }}; | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 1341 | quote! { | COMMENT |
| LOW | facet-macros-impl/src/attr_grammar/make_parse_attr.rs | 1401 | // import the Attr enum (dependency direction: facet depends on facet-core). | COMMENT |
| LOW | facet-testhelpers/src/lib.rs | 1 | #![warn(missing_docs)] | COMMENT |
| LOW | facet-testhelpers/src/lib.rs | 21 | //! fn my_test() { | COMMENT |
| LOW | facet-testhelpers/src/lib.rs | 161 | /// | COMMENT |
| LOW | facet-showcase/src/lib.rs | 1 | //! Unified showcase infrastructure for facet format crates. | COMMENT |
| LOW | facet-showcase/src/output.rs | 1 | //! Output mode detection and configuration. | COMMENT |
| LOW | facet-macros/src/lib.rs | 1 | //! [](https://coverall | COMMENT |
| LOW | facet-macros/src/lib.rs | 21 | #[doc(hidden)] | COMMENT |
| LOW | facet-macros/src/lib.rs | 41 | /// Internal proc macro for unified attribute dispatch. | COMMENT |
| LOW | facet-macros/src/lib.rs | 61 | /// Internal proc macro for attribute error messages. | COMMENT |
| LOW | facet-macros/src/lib.rs | 101 | } | COMMENT |
| LOW | facet-macros/src/lib.rs | 121 | /// 3. Call each registered plugin's code generator | COMMENT |
| LOW | facet-macros/src/lib.rs | 141 | #[doc(hidden)] | COMMENT |
| LOW | facet-macros/src/lib.rs | 161 | /// | COMMENT |
| LOW | facet-macro-template/src/lib.rs | 1 | //! # Facet Macro Template | COMMENT |
| LOW | docs/content/reference/container-attributes.md | 141 | COMMENT | |
| LOW | facet-validate/src/lib.rs | 1 | //! Validation attributes for facet. | COMMENT |
| LOW | facet-validate/src/lib.rs | 21 | //! pub contact_email: String, | COMMENT |
| LOW | facet-validate/src/lib.rs | 41 | //! | `min_length` | `validate::min_length = 1` | String, Vec, slices | | COMMENT |
| LOW | facet-validate/src/lib.rs | 101 | /// | COMMENT |
| 453 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 8 | // ── Test types ────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 35 | // ── Success: struct field mutation ─────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 74 | // ── Success: list element mutation ────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 95 | // ── Success: enum variant field mutation ───────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 136 | // ── Success: empty path returns root ──────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 149 | // ── Error: root shape mismatch ────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 161 | // ── Error: field out of bounds ────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 182 | // ── Error: list index out of bounds ───────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 208 | // ── Error: variant mismatch ───────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/poke/at_path.rs | 229 | // ── Error: unsupported step kinds ─────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 6 | // ── Test types ────────────────────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 44 | // ── Success: struct field ─────────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 81 | // ── Success: list index ───────────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 101 | // ── Success: enum variant + field ─────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 134 | // ── Success: Option ───────────────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 150 | // ── Success: Box (pointer deref) ──────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 168 | // ── Success: map ──────────────────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 186 | // ── Success: empty path returns root ──────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 198 | // ── Error: root shape mismatch ────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 211 | // ── Error: wrong step kind ────────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 243 | // ── Error: field out of bounds ────────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 264 | // ── Error: list index out of bounds ───────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 291 | // ── Error: enum variant mismatch ──────────────────────────────────── | COMMENT |
| MEDIUM | facet-reflect/tests/peek/at_path.rs | 313 | // ── Error: option is None ─────────────────────────────────────────── | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | facet-macros-impl/src/process_enum.rs | 11 | /// NOTE: This function generates code that uses short aliases from the 𝟋 prelude. | COMMENT |
| LOW | facet-macros-impl/src/process_enum.rs | 41 | /// NOTE: This function generates code that uses short aliases from the 𝟋 prelude. | COMMENT |
| LOW⚡ | docs/content/reference/field-attributes.md | 379 | // Step 1: Create a transparent proxy that wraps String | COMMENT |
| LOW⚡ | docs/content/reference/field-attributes.md | 384 | // Step 2: Implement TryFrom for deserialization (Proxy → Color) | COMMENT |
| LOW⚡ | docs/content/reference/field-attributes.md | 393 | // Step 3: Implement TryFrom for serialization (Color → Proxy) | COMMENT |
| LOW⚡ | docs/content/reference/field-attributes.md | 402 | // Step 4: Use the proxy attribute on your field | COMMENT |
| LOW⚡ | facet-solver/tests/integration/solver.rs | 472 | // Step 1: Probe to find configuration | COMMENT |
| LOW⚡ | facet-solver/tests/integration/solver.rs | 481 | // Step 2: Deserialize using resolved config | COMMENT |
| LOW⚡ | facet-solver/tests/integration/solver.rs | 509 | // Step 1: Probe to find configuration | COMMENT |
| LOW⚡ | facet-solver/tests/integration/solver.rs | 518 | // Step 2: Deserialize using resolved config | COMMENT |
| LOW | facet-reflect/docs/partial-ownership-redesign.md | 280 | ### Step 1: Add `iset.unset(idx)` in `begin_nth_struct_field` | COMMENT |
| LOW | facet-reflect/docs/partial-ownership-redesign.md | 297 | ### Step 2: Verify `end()` already sets iset | COMMENT |
| LOW | facet-reflect/docs/partial-ownership-redesign.md | 307 | ### Step 3: Simplify drop logic | COMMENT |
| LOW | facet-reflect/docs/partial-ownership-redesign.md | 339 | ### Step 4: Remove `current_child` from Tracker variants | COMMENT |
| LOW | facet-reflect/docs/partial-ownership-redesign.md | 349 | ### Step 5: Rename `is_init` to `state` | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| CRITICAL | facet-reflect/src/peek/set.rs | 103 | let iter_init_with_value_fn = self.def.vtable.iter_vtable.init_with_value.unwrap(); | CODE |
| CRITICAL | facet-reflect/src/peek/map.rs | 148 | let iter_init_with_value_fn = self.def.vtable.iter_vtable.init_with_value.unwrap(); | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | facet-solver/src/lib.rs | 1395 | /// # Why not just use `see_key()` results? | COMMENT |
| MEDIUM | facet-macro-parse/src/generic_params.rs | 438 | // Compare string representations for robust assertion | COMMENT |
| MEDIUM | facet-macro-parse/src/generic_params.rs | 449 | // Compare string representations for robust assertion | COMMENT |
| MEDIUM | facet-core/src/types/specialization.rs | 24 | /// It wraps a value and is used in conjunction with trait implementations that leverage | COMMENT |
| MEDIUM | facet-core/src/types/specialization.rs | 36 | /// trait implementations that leverage Rust's method resolution rules to select different | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW⚡ | facet-solver/tests/integration/solver.rs | 472 | // Step 1: Probe to find configuration | COMMENT |
| LOW⚡ | facet-solver/tests/integration/solver.rs | 481 | // Step 2: Deserialize using resolved config | COMMENT |
| LOW⚡ | facet-solver/tests/integration/solver.rs | 509 | // Step 1: Probe to find configuration | COMMENT |
| LOW⚡ | facet-solver/tests/integration/solver.rs | 518 | // Step 2: Deserialize using resolved config | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | facet-pretty/tests/integration/pretty_print.rs | 41 | street: "123 Main St".to_string(), | CODE |
| LOW | facet-pretty/examples/pretty_basic.rs | 20 | street: "123 Main St".to_string(), | CODE |
| LOW | facet-pretty/examples/pretty_showcase.rs | 341 | name: "Acme Corp".into(), | CODE |
| LOW | facet-pretty/examples/pretty_showcase.rs | 343 | street: "123 Main St".into(), | CODE |
| LOW | facet-reflect/tests/partial/misc.rs | 1334 | .set("John Doe".to_string())? | CODE |
| LOW | facet-reflect/tests/partial/misc.rs | 1344 | name: "John Doe".to_string(), | CODE |
| LOW | facet-reflect/src/partial/mod.rs | 32 | //! partial = partial.set_field("street", "123 Main St")?; | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | scripts/lldb-wrapper.sh | 5 | # Create a temp script that conditionally shows backtrace | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | scripts/lldb-crash-handler.py | 34 | # Check if stopped due to signal (crash) | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | scripts/lldb-crash-handler.py | 10 | CODE |