Document combined group filtering

[j178]

Closes #2493

[Copilot]

Pull request overview

Documents and regression-tests how prek run composes --group, --require-group, and --no-group filters (OR for repeated --group, AND for repeated --require-group, exclusion wins), addressing the clarification requested in #2493.

Changes:

• Add consistent “combined filtering” explanation + concrete example to the hook-groups proposal and configuration reference.
• Expand CLI option docs for --group / --require-group to spell out OR/AND composition and interaction with --no-group / argument order.
• Add a regression test that exercises combined filters and verifies argument-order independence.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
docs/reference/configuration.md	Adds an explicit example showing fast AND (format OR lint-only) selection semantics.
docs/reference/cli.md	Clarifies --group (OR semantics) and --require-group (AND semantics) and their composition with --no-group.
docs/proposals/hook-groups.md	Adds an equivalent boolean-style description and the same concrete example for clarity/consistency.
crates/prek/tests/run.rs	Adds a snapshot covering combined --group/--require-group/--no-group filtering and order independence.
crates/prek/src/cli/mod.rs	Updates Clap help text so generated CLI docs reflect the clarified semantics.

---

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.61%. Comparing base (ea6a310) to head (8ca82fb).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2495      +/-   ##
==========================================
+ Coverage   93.39%   93.61%   +0.22%     
==========================================
  Files         131      131              
  Lines       28359    28359              
==========================================
+ Hits        26486    26549      +63     
+ Misses       1873     1810      -63     

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[prek-ci-bot]

📦 Cargo Bloat Comparison

Binary size change: +0.00% (29.6 MiB → 29.6 MiB)

Expand for cargo-bloat output

Head Branch Results

 File  .text     Size             Crate Name
 1.1%   2.3% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_encrypt_avx512
 1.1%   2.3% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_decrypt_avx512
 0.2%   0.5%  71.1KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  57.5KiB              prek prek::run::{closure#0}
 0.2%   0.4%  56.1KiB              prek <<prek::config::Config as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.2%   0.3%  49.4KiB annotate_snippets annotate_snippets::renderer::render::render
 0.2%   0.3%  45.8KiB              prek <prek::languages::ruby::installer::RubyInstaller>::install::{closure#0}
 0.1%   0.3%  38.7KiB              prek <prek::languages::node::installer::NodeInstaller>::install::{closure#0}
 0.1%   0.3%  38.6KiB              prek prek::cli::run::run::run::{closure#0}
 0.1%   0.2%  34.4KiB              prek <prek::cli::RunOptions as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  32.9KiB              prek <prek::languages::golang::installer::GoInstaller>::install::{closure#0}
 0.1%   0.2%  31.4KiB              prek <prek::languages::bun::installer::BunInstaller>::install::{closure#0}
 0.1%   0.2%  30.1KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  28.9KiB    cargo_metadata <&mut serde_json::de::Deserializer<serde_json::read::StrRead> as serde_core::de::Deserializer>::deserialize_struct::<<cargo_metadata::Package as serde_core::de::Deserialize>::deserialize::__Visitor>
 0.1%   0.2%  28.4KiB              prek <<prek::config::RemoteHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble
 0.1%   0.2%  26.7KiB              prek <prek::languages::deno::installer::DenoInstaller>::download::{closure#0}
 0.1%   0.2%  25.2KiB              prek prek::cli::try_repo::try_repo::{closure#0}
 0.1%   0.2%  25.2KiB              prek <<prek::config::LocalHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
42.1%  87.9%  12.5MiB                   And 26378 smaller methods. Use -n N to show more.
47.9% 100.0%  14.2MiB                   .text section size, the file size is 29.6MiB

Base Branch Results

 File  .text     Size             Crate Name
 1.1%   2.3% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_encrypt_avx512
 1.1%   2.3% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_decrypt_avx512
 0.2%   0.5%  71.1KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  57.5KiB              prek prek::run::{closure#0}
 0.2%   0.4%  56.1KiB              prek <<prek::config::Config as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.2%   0.3%  49.4KiB annotate_snippets annotate_snippets::renderer::render::render
 0.2%   0.3%  45.8KiB              prek <prek::languages::ruby::installer::RubyInstaller>::install::{closure#0}
 0.1%   0.3%  38.7KiB              prek <prek::languages::node::installer::NodeInstaller>::install::{closure#0}
 0.1%   0.3%  38.6KiB              prek prek::cli::run::run::run::{closure#0}
 0.1%   0.2%  34.4KiB              prek <prek::cli::RunOptions as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  32.9KiB              prek <prek::languages::golang::installer::GoInstaller>::install::{closure#0}
 0.1%   0.2%  31.4KiB              prek <prek::languages::bun::installer::BunInstaller>::install::{closure#0}
 0.1%   0.2%  30.1KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  28.9KiB    cargo_metadata <&mut serde_json::de::Deserializer<serde_json::read::StrRead> as serde_core::de::Deserializer>::deserialize_struct::<<cargo_metadata::Package as serde_core::de::Deserialize>::deserialize::__Visitor>
 0.1%   0.2%  28.4KiB              prek <<prek::config::RemoteHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble
 0.1%   0.2%  26.7KiB              prek <prek::languages::deno::installer::DenoInstaller>::download::{closure#0}
 0.1%   0.2%  25.2KiB              prek prek::cli::try_repo::try_repo::{closure#0}
 0.1%   0.2%  25.2KiB              prek <<prek::config::LocalHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
42.1%  87.9%  12.5MiB                   And 26378 smaller methods. Use -n N to show more.
47.9% 100.0%  14.2MiB                   .text section size, the file size is 29.6MiB

[prek-ci-bot]

⚡️ Hyperfine Benchmarks

Summary: 0 regressions, 1 improvements above the 10% threshold.

Environment

• OS: Linux 6.17.0-1020-azure
• CPU: 4 cores
• prek version: prek 0.4.12+12 (c9c944f 2026-08-07)
• Rust version: rustc 1.97.1 (8bab26f4f 2026-07-14)
• Hyperfine version: hyperfine 1.20.0

CLI Commands

Benchmarking basic commands in the main repo:

prek --version

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base --version	2.2 ± 0.1	2.1	2.6	1.03 ± 0.05
prek-head --version	2.1 ± 0.1	2.0	2.3	1.00

prek list

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base list	9.4 ± 0.3	9.0	11.4	1.00
prek-head list	9.6 ± 0.4	9.0	11.5	1.02 ± 0.05

prek validate-config .pre-commit-config.yaml

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base validate-config .pre-commit-config.yaml	3.2 ± 0.1	3.0	3.5	1.00
prek-head validate-config .pre-commit-config.yaml	3.5 ± 0.6	3.1	7.5	1.09 ± 0.20

prek sample-config

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base sample-config	2.5 ± 0.1	2.4	2.7	1.01 ± 0.06
prek-head sample-config	2.5 ± 0.1	2.4	3.4	1.00

Cold vs Warm Runs

Comparing first run (cold) vs subsequent runs (warm cache):

prek run --all-files (cold - no cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	37.6 ± 1.1	36.2	39.4	1.01 ± 0.04
prek-head run --all-files	37.3 ± 0.8	36.0	38.2	1.00

prek run --all-files (warm - with cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	37.9 ± 1.2	35.4	39.7	1.00 ± 0.04
prek-head run --all-files	37.8 ± 1.1	36.7	41.0	1.00

Full Hook Suite

Running the builtin hook suite on the benchmark workspace:

prek run --all-files (full builtin hook suite)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	37.6 ± 1.2	35.6	39.5	1.00
prek-head run --all-files	38.1 ± 1.2	35.2	40.2	1.01 ± 0.04

Individual Hook Performance

Benchmarking each hook individually on the test repo:

prek run trailing-whitespace --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run trailing-whitespace --all-files	12.9 ± 0.3	12.4	13.7	1.00
prek-head run trailing-whitespace --all-files	13.0 ± 0.5	12.3	14.4	1.00 ± 0.05

prek run end-of-file-fixer --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run end-of-file-fixer --all-files	10.8 ± 0.5	10.0	12.1	1.00
prek-head run end-of-file-fixer --all-files	11.2 ± 0.5	10.5	12.4	1.04 ± 0.06

prek run check-json --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-json --all-files	7.7 ± 0.3	7.0	8.3	1.01 ± 0.05
prek-head run check-json --all-files	7.7 ± 0.3	7.2	8.5	1.00

prek run check-yaml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-yaml --all-files	7.6 ± 0.5	7.3	10.3	1.01 ± 0.08
prek-head run check-yaml --all-files	7.6 ± 0.2	7.2	7.9	1.00

prek run check-toml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-toml --all-files	7.6 ± 0.2	7.1	8.2	1.01 ± 0.05
prek-head run check-toml --all-files	7.6 ± 0.3	6.9	8.2	1.00

prek run check-xml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-xml --all-files	7.6 ± 0.8	7.0	11.4	1.00 ± 0.12
prek-head run check-xml --all-files	7.6 ± 0.5	7.1	8.8	1.00

prek run detect-private-key --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run detect-private-key --all-files	10.9 ± 0.5	10.1	12.1	1.00
prek-head run detect-private-key --all-files	11.2 ± 0.7	10.3	13.8	1.03 ± 0.08

prek run fix-byte-order-marker --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run fix-byte-order-marker --all-files	12.6 ± 0.8	11.5	14.4	1.00
prek-head run fix-byte-order-marker --all-files	12.6 ± 0.9	11.2	14.6	1.00 ± 0.09

Installation Performance

Benchmarking hook installation (fast path hooks skip Python setup):

prek install-hooks (cold - no cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base install-hooks	5.5 ± 2.0	4.5	9.2	1.20 ± 0.44
prek-head install-hooks	4.6 ± 0.0	4.6	4.6	1.00

✅ Performance improvement for prek install-hooks (cold - no cache): 16.7300% faster

prek install-hooks (warm - with cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base install-hooks	4.6 ± 0.0	4.6	4.6	1.01 ± 0.02
prek-head install-hooks	4.6 ± 0.1	4.4	4.6	1.00

File Filtering/Scoping Performance

Testing different file selection modes:

prek run (staged files only)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run	23.7 ± 0.5	22.9	25.0	1.01 ± 0.03
prek-head run	23.6 ± 0.4	23.1	24.3	1.00

prek run --files '*.json' (specific file type)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --files '*.json'	5.1 ± 0.1	5.0	5.2	1.01 ± 0.02
prek-head run --files '*.json'	5.0 ± 0.1	4.9	5.1	1.00

Workspace Discovery & Initialization

Benchmarking hook discovery and initialization overhead:

prek run --dry-run --all-files (measures init overhead)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --dry-run --all-files	6.7 ± 0.1	6.6	6.9	1.00
prek-head run --dry-run --all-files	6.9 ± 0.5	6.6	8.5	1.02 ± 0.07

Meta Hooks Performance

Benchmarking meta hooks separately:

prek run check-hooks-apply --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-hooks-apply --all-files	8.0 ± 0.1	7.8	8.1	1.00
prek-head run check-hooks-apply --all-files	8.2 ± 0.2	8.0	8.7	1.02 ± 0.03

prek run check-useless-excludes --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-useless-excludes --all-files	8.2 ± 0.2	8.0	8.8	1.01 ± 0.03
prek-head run check-useless-excludes --all-files	8.2 ± 0.1	8.0	8.4	1.00

prek run identity --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run identity --all-files	7.0 ± 0.1	6.8	7.4	1.00
prek-head run identity --all-files	7.1 ± 0.1	6.9	7.3	1.00 ± 0.03