feat: strength calculation & documentation improvements (#21)

.github/workflows/ci.yml

@@ -131,7 +131,9 @@ jobs:
                   github_token: ${{ secrets.GITHUB_TOKEN }}
 
             - name: Generate coverage
-              run: cargo llvm-cov --all-features --no-report
+              # Use --test-threads=1 to prevent race conditions in stdin-mocking tests
+              # that manipulate file descriptors (dup/dup2) which aren't thread-safe
+              run: cargo llvm-cov --all-features --no-report -- --test-threads=1
 
             - name: Combine coverage reports
               run: cargo llvm-cov report --lcov --output-path lcov.info

.serena/project.yml

@@ -84,6 +84,27 @@ excluded_tools: []
 # initial prompt for the project. It will always be given to the LLM upon activating the project
 # (contrary to the memories, which are loaded on demand).
 initial_prompt: ""
-
+# the name by which the project can be referenced within Serena
 project_name: "libmagic-rs"
+
+# list of tools to include that would otherwise be disabled (particularly optional tools that are disabled by default)
 included_optional_tools: []
+
+# list of mode names to that are always to be included in the set of active modes
+# The full set of modes to be activated is base_modes + default_modes.
+# If the setting is undefined, the base_modes from the global configuration (serena_config.yml) apply.
+# Otherwise, this setting overrides the global configuration.
+# Set this to [] to disable base modes for this project.
+# Set this to a list of mode names to always include the respective modes for this project.
+base_modes:
+
+# list of mode names that are to be activated by default.
+# The full set of modes to be activated is base_modes + default_modes.
+# If the setting is undefined, the default_modes from the global configuration (serena_config.yml) apply.
+# Otherwise, this overrides the setting from the global configuration (serena_config.yml).
+# This setting can, in turn, be overridden by CLI parameters (--mode).
+default_modes:
+
+# fixed set of tools to use as the base tool set (if non-empty), replacing Serena's default set of tools.
+# This cannot be combined with non-empty excluded_tools or included_optional_tools.
+fixed_tools: []

AGENTS.md

@@ -21,6 +21,7 @@ This document provides comprehensive guidelines for AI assistants working on the
 - **Bounds checking** for all buffer access using `.get()` methods
 - **Safe resource management** with RAII patterns
 - **Graceful error handling** for malformed inputs
+- **Safe string operations**: Use `strip_prefix()`/`strip_suffix()` instead of direct slicing (`&str[n..]`) to avoid UTF-8 panics
 
 ### 2. Zero-Warnings Policy
 
@@ -44,6 +45,7 @@ This document provides comprehensive guidelines for AI assistants working on the
 - Use `cargo nextest` for faster, more reliable test execution
 - Include property tests with `proptest` for fuzzing
 - Benchmark critical path components with `criterion`
+- Verify doc examples with `cargo test --doc` - ensure example strings don't accidentally match multiple patterns
 
 ## Architecture Patterns
 
@@ -91,6 +93,14 @@ evaluator/
 
 - Avoid using emojis and other non-ASCII characters in code, comments, or documentation, except when the code is handling non-plaintext characters (for example: em dash, en dash, or other non-ASCII symbols).
 
+### Case-Insensitive Matching Pattern
+
+When implementing case-insensitive string matching:
+
+- Lowercase inputs at ALL entry points (constructors, setters)
+- Store normalized values internally
+- Document the case-insensitivity in public API docs
+
 ### Error Handling Patterns
 
 ```rust

build.rs

@@ -21,7 +21,7 @@ mod error;
 mod parser;
 
 use error::ParseError;
-use parser::ast::{Endianness, MagicRule, OffsetSpec, Operator, TypeKind, Value};
+use parser::ast::{Endianness, MagicRule, OffsetSpec, Operator, StrengthModifier, TypeKind, Value};
 use parser::parse_text_magic_file;
 use std::env;
 use std::fs;
@@ -32,6 +32,7 @@ const INDENT_WIDTH: usize = 4;
 
 fn main() {
     println!("cargo:rerun-if-changed=src/builtin_rules.magic");
+    println!("cargo:rerun-if-changed=build.rs");
 
     let manifest_dir = match env::var("CARGO_MANIFEST_DIR") {
         Ok(value) => value,
@@ -109,9 +110,11 @@ fn format_parse_error(error: &ParseError) -> String {
 fn generate_builtin_rules(rules: &[MagicRule]) -> String {
     let mut output = String::new();
 
+    // Allow unused_imports since StrengthModifier may not be used if no rules have strength modifiers
+    push_line(&mut output, "#[allow(unused_imports)]");
     push_line(
         &mut output,
-        "use crate::parser::ast::{MagicRule, OffsetSpec, TypeKind, Operator, Value, Endianness};",
+        "use crate::parser::ast::{MagicRule, OffsetSpec, TypeKind, Operator, Value, Endianness, StrengthModifier};",
     );
     push_line(&mut output, "use std::sync::LazyLock;");
     push_line(&mut output, "");
@@ -200,12 +203,30 @@ fn serialize_magic_rule(rule: &MagicRule, indent: usize) -> String {
         &rule.level.to_string(),
     );
 
+    push_field(
+        &mut output,
+        indent + INDENT_WIDTH,
+        "strength_modifier",
+        &serialize_strength_modifier(&rule.strength_modifier),
+    );
+
     push_indent(&mut output, indent);
     output.push('}');
 
     output
 }
 
+fn serialize_strength_modifier(modifier: &Option<StrengthModifier>) -> String {
+    match modifier {
+        None => "None".to_string(),
+        Some(StrengthModifier::Add(val)) => format!("Some(StrengthModifier::Add({val}))"),
+        Some(StrengthModifier::Subtract(val)) => format!("Some(StrengthModifier::Subtract({val}))"),
+        Some(StrengthModifier::Multiply(val)) => format!("Some(StrengthModifier::Multiply({val}))"),
+        Some(StrengthModifier::Divide(val)) => format!("Some(StrengthModifier::Divide({val}))"),
+        Some(StrengthModifier::Set(val)) => format!("Some(StrengthModifier::Set({val}))"),
+    }
+}
+
 fn serialize_children(children: &[MagicRule], indent: usize) -> String {
     if children.is_empty() {
         return "Vec::new()".to_string();