ruby-optimise

# Community Ruby Best Practices Comprehensive performance optimization guide for Ruby applications, maintained by the community. Contains 42 rules across 8 categories, prioritized by impact to guide automated refactoring and code generation. ## When to Apply Reference these guidelines when: - Writing new Ruby code or gems - Optimizing ActiveRecord queries and database access patterns - Processing large collections or building data pipelines - Reviewing code for memory bloat and GC pressure - Configuring Ruby runtime settings for production ## Rule Categories by Priority | Priority | Category | Impact | Prefix | |----------|----------|--------|--------| | 1 | Object Allocation | CRITICAL | `alloc-` | | 2 | Collection & Enumeration | CRITICAL | `enum-` | | 3 | I/O & Database | HIGH | `io-` | | 4 | String Handling | HIGH | `str-` | | 5 | Method & Dispatch | MEDIUM-HIGH | `meth-` | | 6 | Data Structures | MEDIUM | `ds-` | | 7 | Concurrency | MEDIUM | `conc-` | | 8 | Runtime & Configuration | LOW-MEDIUM | `runtime-` | ## Quick Reference ### 1. Object Allocation (CRITICAL) - [`alloc-avoid-unnecessary-dup`](references/alloc-avoid-unnecessary-dup.md) - Avoid Unnecessary Object Duplication - [`alloc-freeze-constants`](references/alloc-freeze-constants.md) - Freeze Constant Collections - [`alloc-lazy-initialization`](references/alloc-lazy-initialization.md) - Use Lazy Initialization for Expensive Objects - [`alloc-avoid-temp-arrays`](references/alloc-avoid-temp-arrays.md) - Avoid Temporary Array Creation - [`alloc-reuse-buffers`](references/alloc-reuse-buffers.md) - Reuse Buffers in Loops - [`alloc-avoid-implicit-conversions`](references/alloc-avoid-implicit-conversions.md) - Avoid Repeated Computation in Hot Paths ### 2. Collection & Enumeration (CRITICAL) - [`enum-single-pass`](references/enum-single-pass.md) - Use Single-Pass Collection Transforms - [`enum-lazy-large-collections`](references/enum-lazy-large-collections.md) - Use Lazy Enumerators for Large Collections - [`enum-flat-map`](references/enum-flat-map.md) - Use flat_map Instead of map.flatten - [`enum-each-with-object`](references/enum-each-with-object.md) - Use each_with_object Over inject for Building Collections - [`enum-avoid-count-in-loops`](references/enum-avoid-count-in-loops.md) - Avoid Recomputing Collection Size in Conditions - [`enum-chunk-batch-processing`](references/enum-chunk-batch-processing.md) - Use each_slice for Batch Processing ### 3. I/O & Database (HIGH) - [`io-eager-load-associations`](references/io-eager-load-associations.md) - Eager Load ActiveRecord Associations - [`io-select-only-needed-columns`](references/io-select-only-needed-columns.md) - Select Only Needed Columns - [`io-batch-find-each`](references/io-batch-find-each.md) - Use find_each for Large Record Sets - [`io-avoid-queries-in-loops`](references/io-avoid-queries-in-loops.md) - Avoid Database Queries Inside Loops - [`io-stream-large-files`](references/io-stream-large-files.md) - Stream Large Files Line by Line - [`io-connection-pool-sizing`](references/io-connection-pool-sizing.md) - Size Connection Pools to Match Thread Count - [`io-cache-expensive-queries`](references/io-cache-expensive-queries.md) - Cache Expensive Database Results ### 4. String Handling (HIGH) - [`str-frozen-literals`](references/str-frozen-literals.md) - Enable Frozen String Literals - [`str-shovel-over-plus`](references/str-shovel-over-plus.md) - Use Shovel Operator for String Building - [`str-interpolation-over-concatenation`](references/str-interpolation-over-concatenation.md) - Use String Interpolation Over Concatenation - [`str-avoid-repeated-gsub`](references/str-avoid-repeated-gsub.md) - Chain gsub Calls into a Single Replacement - [`str-symbol-for-identifiers`](references/str-symbol-for-identifiers.md) - Use Symbols for Identifiers and Hash Keys ### 5. Method & Dispatch (MEDIUM-HIGH) - [`meth-avoid-method-missing-hot-paths`](references/meth-avoid-method-missing-hot-paths.md) - Avoid method_missing in Hot Paths - [`meth-cache-method-references`](references/meth-cache-method-references.md) - Cache Method References for Repeated Calls - [`meth-block-vs-proc`](references/meth-block-vs-proc.md) - Pass Blocks Directly Instead of Converting to Proc - [`meth-avoid-dynamic-send`](references/meth-avoid-dynamic-send.md) - Avoid Dynamic send in Performance-Critical Code - [`meth-reduce-method-chain-depth`](references/meth-reduce-method-chain-depth.md) - Reduce Method Chain Depth in Hot Loops ### 6. Data Structures (MEDIUM) - [`ds-set-for-membership`](references/ds-set-for-membership.md) - Use Set for Membership Tests - [`ds-struct-over-openstruct`](references/ds-struct-over-openstruct.md) - Use Struct Over OpenStruct - [`ds-sort-by-over-sort`](references/ds-sort-by-over-sort.md) - Use sort_by Instead of sort with Block - [`ds-array-preallocation`](references/ds-array-preallocation.md) - Preallocate Arrays When Size Is Known - [`ds-hash-default-value`](references/ds-hash-default-value.md) - Use Hash Default Values Instead of Conditional Assignment ### 7. Concurrency (MEDIUM) - [`conc-fiber-for-io`](references/conc-fiber-for-io.md) - Use Fibers for I/O-Bound Concurrency - [`conc-thread-pool-sizing`](references/conc-thread-pool-sizing.md) - Size Thread Pools to Match Workload - [`conc-ractor-cpu-bound`](references/conc-ractor-cpu-bound.md) - Use Ractors for CPU-Bound Parallelism - [`conc-avoid-shared-mutable-state`](references/conc-avoid-shared-mutable-state.md) - Avoid Shared Mutable State Between Threads ### 8. Runtime & Configuration (LOW-MEDIUM) - [`runtime-enable-yjit`](references/runtime-enable-yjit.md) - Enable YJIT for Production - [`runtime-tune-gc-parameters`](references/runtime-tune-gc-parameters.md) - Tune GC Parameters for Your Workload - [`runtime-frozen-string-literal-default`](references/runtime-frozen-string-literal-default.md) - Set Frozen String Literal as Project Default - [`runtime-optimize-require`](references/runtime-optimize-require.md) - Optimize Require Load Order ## How to Use Read individual reference files for detailed explanations and code examples: - [Section definitions](references/_sections.md) - Category structure and impact levels - [Rule template](assets/templates/_template.md) - Template for adding new rules ## Reference Files | File | Description | |------|-------------| | [references/_sections.md](references/_sections.md) | Category definitions and ordering | | [assets/templates/_template.md](assets/templates/_template.md) | Template for new rules | | [metadata.json](metadata.json) | Version and reference information |