Add mise language support

[j178]

Closes #2022

[codecov]

Codecov Report

❌ Patch coverage is 93.53234% with 26 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.63%. Comparing base (a958731) to head (9936138).
⚠️ Report is 4 commits behind head on master.

Files with missing lines	Patch %	Lines
crates/prek/src/languages/mise/installer.rs	90.66%	21 Missing ⚠️
crates/prek/src/languages/mise/mise.rs	97.70%	3 Missing ⚠️
crates/prek/src/languages/mod.rs	84.61%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2540      +/-   ##
==========================================
+ Coverage   93.60%   93.63%   +0.02%     
==========================================
  Files         131      134       +3     
  Lines       28401    28821     +420     
==========================================
+ Hits        26586    26986     +400     
- Misses       1815     1835      +20     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

Adds first-class language: mise support so prek can provision and activate hook tool dependencies via mise, expanding the set of supported tool backends beyond what pre-commit natively provides.

Changes:

• Introduces a new mise language backend that can download/locate a compatible mise CLI, install additional_dependencies, and activate tools into PATH.
• Extends the language/runtime plumbing to support async, cwd-dependent environment preparation before command resolution/execution.
• Updates docs, schema, CI matrix, and adds integration tests covering managed and system mise scenarios.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
scripts/generate-ci-matrix.py	Adds mise to the CI language test matrix.
README.md	Documents mise as supported and managed where needed.
prek.schema.json	Adds mise to schema properties and allowed language values.
docs/reference/cli.md	Includes mise in the documented language list.
docs/languages.md	Adds detailed mise language documentation and examples.
crates/prek/tests/languages/mise.rs	New tests for managed download + deps and system mise activation behavior.
crates/prek/tests/languages/main.rs	Registers the new mise test module.
crates/prek/src/store.rs	Adds ToolBucket::Mise for managed tool storage.
crates/prek/src/languages/version.rs	Reuses semver-based language_version parsing for mise and exposes SemverRequest::matches.
crates/prek/src/languages/mod.rs	Adds mise backend wiring and a new async env-prep hook in the backend trait.
crates/prek/src/languages/mise/mod.rs	New mise language module with helpers for isolating inherited mise env vars.
crates/prek/src/languages/mise/mise.rs	Implements the LanguageBackend for mise (install, health check, activation).
crates/prek/src/languages/mise/installer.rs	Adds installer/downloader logic for locating/downloading compatible mise releases.
crates/prek/src/config.rs	Adds Language::Mise to the config language enum.
crates/prek/src/checksum.rs	Improves SHA256SUMS parsing to handle ./filename entries.
crates/prek-consts/src/env_vars.rs	Adds mise-related env var constants and an internal binary-name override.
AGENTS.md	Updates contributor guidance to prefer if/else over .then() / .then_some().

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[prek-ci-bot]

📦 Cargo Bloat Comparison

Binary size change: +2.03% (29.6 MiB → 30.2 MiB)

Expand for cargo-bloat output

Head Branch Results

 File  .text     Size             Crate Name
 1.1%   2.2% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_encrypt_avx512
 1.1%   2.2% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_decrypt_avx512
 0.3%   0.6%  85.7KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  57.4KiB              prek prek::run::{closure#0}
 0.2%   0.4%  55.0KiB              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
 0.1%   0.3%  39.7KiB              prek prek::cli::run::run::run::{closure#0}
 0.1%   0.2%  34.3KiB              prek <prek::cli::RunOptions as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  32.9KiB              prek <prek::languages::ruby::installer::RubyInstaller>::install::{closure#0}
 0.1%   0.2%  30.5KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  28.6KiB    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%  28.0KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.6KiB              prek <prek::languages::node::installer::NodeInstaller>::install::{closure#0}
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble
 0.1%   0.2%  27.5KiB              prek <prek::languages::mise::installer::MiseInstaller>::download::{closure#0}
 0.1%   0.2%  27.2KiB              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%  26.6KiB              prek prek::cli::try_repo::try_repo::{closure#0}
 0.1%   0.2%  24.9KiB               xml <xml::reader::parser::PullParser>::dispatch_token
 0.1%   0.2%  24.2KiB              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>
 0.1%   0.2%  23.5KiB              prek <<prek::config::UpdateOptions 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>
42.8%  88.4%  12.9MiB                   And 26658 smaller methods. Use -n N to show more.
48.4% 100.0%  14.6MiB                   .text section size, the file size is 30.2MiB

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%  72.5KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  58.0KiB              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%  47.9KiB              prek prek::run::{closure#0}
 0.1%   0.3%  38.5KiB              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%  33.0KiB              prek <prek::languages::ruby::installer::RubyInstaller>::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%  29.4KiB              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%  28.6KiB    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%  28.0KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.5KiB              prek <prek::languages::deno::installer::DenoInstaller>::download::{closure#0}
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble
 0.1%   0.2%  25.7KiB              prek prek::cli::try_repo::try_repo::{closure#0}
 0.1%   0.2%  25.6KiB              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>
 0.1%   0.2%  25.2KiB              prek <<prek::config::UpdateOptions 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%  24.9KiB               xml <xml::reader::parser::PullParser>::dispatch_token
 0.1%   0.2%  24.3KiB              prek prek::cli::update::update::{closure#0}
42.3%  88.2%  12.5MiB                   And 26217 smaller methods. Use -n N to show more.
48.0% 100.0%  14.2MiB                   .text section size, the file size is 29.6MiB

[prek-ci-bot]

⚡️ Hyperfine Benchmarks

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

Environment

• OS: Linux 6.17.0-1020-azure
• CPU: 4 cores
• prek version: prek 0.4.12+43 (f0bc2ca 2026-08-10)
• 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	2.4 ± 0.1	2.2	2.6	1.02 ± 0.07
prek-head --version	2.4 ± 0.1	2.2	2.8	1.00

prek list

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base list	9.9 ± 0.2	9.5	10.5	1.01 ± 0.04
prek-head list	9.8 ± 0.3	9.0	10.3	1.00

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

⏭️ Skipped: .pre-commit-config.yaml not found

prek sample-config

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base sample-config	2.7 ± 0.1	2.5	2.8	1.01 ± 0.04
prek-head sample-config	2.6 ± 0.1	2.5	2.8	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	41.1 ± 1.5	39.2	43.7	1.00
prek-head run --all-files	41.2 ± 1.4	38.9	42.7	1.00 ± 0.05

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

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	40.9 ± 1.0	38.7	42.5	1.01 ± 0.04
prek-head run --all-files	40.6 ± 1.3	38.7	43.7	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	40.7 ± 1.1	38.2	42.7	1.00
prek-head run --all-files	40.8 ± 1.0	38.4	43.2	1.00 ± 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	14.4 ± 0.4	13.5	15.4	1.01 ± 0.04
prek-head run trailing-whitespace --all-files	14.2 ± 0.4	13.5	14.9	1.00

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	12.3 ± 0.6	11.5	13.6	1.02 ± 0.06
prek-head run end-of-file-fixer --all-files	12.1 ± 0.4	11.2	12.9	1.00

prek run check-json --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-json --all-files	8.8 ± 0.3	8.2	9.3	1.00 ± 0.04
prek-head run check-json --all-files	8.8 ± 0.3	8.4	9.3	1.00

prek run check-yaml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-yaml --all-files	8.6 ± 0.2	8.1	9.1	1.00
prek-head run check-yaml --all-files	8.8 ± 0.2	8.3	9.3	1.03 ± 0.03

prek run check-toml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-toml --all-files	9.0 ± 0.3	8.4	9.7	1.04 ± 0.05
prek-head run check-toml --all-files	8.7 ± 0.3	8.1	9.1	1.00

prek run check-xml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-xml --all-files	8.7 ± 0.4	8.3	10.1	1.02 ± 0.07
prek-head run check-xml --all-files	8.5 ± 0.4	8.1	9.9	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	12.2 ± 0.5	11.5	13.4	1.02 ± 0.06
prek-head run detect-private-key --all-files	12.0 ± 0.5	11.0	13.2	1.00

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	14.2 ± 0.8	12.8	16.0	1.00 ± 0.08
prek-head run fix-byte-order-marker --all-files	14.2 ± 0.7	13.0	15.7	1.00

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	5.1 ± 0.1	4.9	5.2	1.05 ± 0.03
prek-head install-hooks	4.8 ± 0.1	4.7	4.8	1.00

prek install-hooks (warm - with cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base install-hooks	4.9 ± 0.1	4.8	5.0	1.00
prek-head install-hooks	5.0 ± 0.1	4.9	5.2	1.02 ± 0.02

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	25.5 ± 0.7	24.4	26.8	1.01 ± 0.04
prek-head run	25.3 ± 0.8	24.2	27.8	1.00

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

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --files '*.json'	5.5 ± 0.1	5.3	5.7	1.01 ± 0.03
prek-head run --files '*.json'	5.4 ± 0.1	5.3	5.6	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	7.6 ± 0.3	7.1	8.0	1.00
prek-head run --dry-run --all-files	7.7 ± 0.1	7.4	7.9	1.01 ± 0.04

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	9.1 ± 0.2	8.9	9.4	1.00
prek-head run check-hooks-apply --all-files	9.3 ± 0.2	9.1	9.7	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	9.1 ± 0.1	9.0	9.3	1.00
prek-head run check-useless-excludes --all-files	9.2 ± 0.1	9.0	9.3	1.01 ± 0.01

prek run identity --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run identity --all-files	8.1 ± 0.2	7.8	8.5	1.00 ± 0.03
prek-head run identity --all-files	8.0 ± 0.1	7.8	8.4	1.00

[Copilot]

Pull request overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated no new comments.

Suppressed comments (1)

crates/prek/src/languages/mise/installer.rs:66

• MiseResult::from_executable aims to keep the version probe from touching user mise state, but it doesn't set MISE_STATE_DIR or MISE_TMP_DIR. If mise uses those defaults outside MISE_DATA_DIR, mise --version can still write into user directories (the comment above notes it runs migrations/pruning). Set these vars to paths inside the temporary directory as well.

            .current_dir(isolated.path())
            .env(EnvVars::CI, "1")
            .env(EnvVars::MISE_DATA_DIR, isolated.path().join("data"))
            .env(EnvVars::MISE_CACHE_DIR, isolated.path().join("cache"))
            .env(EnvVars::MISE_CONFIG_DIR, isolated.path().join("config"))

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: b0ee67a3ec

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[Copilot]

Pull request overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 9936138089

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Run hooks with the selected system mise

When PATH contains an incompatible mise before a compatible one, find_system_mise skips the first executable and records the later one, but this branch leaves PATH unchanged for system installations. A hook whose entry invokes mise therefore runs the first, incompatible executable instead of the toolchain that satisfied its language_version; ensure the selected system executable wins without moving its entire parent directory ahead of unrelated programs.

Useful? React with 👍 / 👎.

[Copilot]

Pull request overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated no new comments.

Suppressed comments (1)

crates/prek/src/languages/mise/installer.rs:244

• Windows mise downloads look incorrect: release_platform() uses an .exe extension and download() copies the downloaded artifact directly to bin/mise.exe, but mise GitHub releases publish Windows artifacts as signed .zip files (e.g. mise-v<VERSION>-windows-x64.zip). As written this will either 404 when downloading or produce a non-executable mise.exe on Windows. Adjust the Windows branch to download the .zip asset and extract bin/mise.exe (you may need a seek-based unzipper or a small preamble-skipper to handle the signed ZIP format).

        let target_binary = target_bin_dir.join("mise").with_extension(EXE_EXTENSION);
        if HOST.operating_system == OperatingSystem::Windows {
            fs_err::tokio::copy(download.path(), &target_binary).await?;
        } else {