Dotnet support by snus-kin · Pull Request #1783 · j178/prek

snus-kin · 2026-03-12T15:34:30Z

Hi, I thought I'd give a stab at dotnet support for prek. Not really an amazing language for how it manages tools & its toolchain, so perhaps some nastiness. Seems to work for csharpier at least for me.

There's some missing tests around the windows part of the code in the coverage but I didn't want to get into messing with CI for windows runners, maybe we can drop the powershell stuff if we make windows people run in a bash type environment?

Not very versed in rust but hoping that even if stuff's bad there's a bit of a start for someone better than I to have a stab at.

Use `:" instead of "@" as the version separator in additional_dependencies to match pre-commit convention (e.g., "csharpier:1.2.6").

codecov · 2026-03-12T15:36:29Z

Codecov Report

❌ Patch coverage is 99.77629% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 92.06%. Comparing base (91a82cb) to head (a35abb4).
⚠️ Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
crates/prek/src/languages/dotnet/installer.rs	99.68%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1783      +/-   ##
==========================================
+ Coverage   91.66%   92.06%   +0.39%     
==========================================
  Files          98      101       +3     
  Lines       19878    20893    +1015     
==========================================
+ Hits        18222    19235    +1013     
- Misses       1656     1658       +2

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prek-ci-bot · 2026-03-12T15:45:32Z

📦 Cargo Bloat Comparison

Binary size change: +0.40% (24.7 MiB → 24.8 MiB)

Expand for cargo-bloat output

Head Branch Results

 File  .text     Size             Crate Name
 1.3%   2.7% 332.0KiB        aws_lc_sys aws_lc_0_38_0_aes_gcm_encrypt_avx512
 1.3%   2.7% 332.0KiB        aws_lc_sys aws_lc_0_38_0_aes_gcm_decrypt_avx512
 0.3%   0.7%  86.2KiB             prek? <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.3%   0.7%  80.7KiB              prek prek::languages::<impl prek::config::Language>::run::{{closure}}::{{closure}}
 0.3%   0.6%  73.2KiB              prek prek::languages::<impl prek::config::Language>::run::{{closure}}::{{closure}}
 0.2%   0.4%  51.2KiB              prek prek::languages::<impl prek::config::Language>::install::{{closure}}
 0.2%   0.4%  51.0KiB annotate_snippets annotate_snippets::renderer::render::render
 0.2%   0.4%  46.1KiB              prek prek::run::{{closure}}
 0.2%   0.3%  41.9KiB              prek prek::cli::run::run::run::{{closure}}
 0.1%   0.3%  31.8KiB             prek? <prek::cli::RunArgs as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_38_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.8KiB      serde_saphyr saphyr_parser_bw::scanner::Scanner<T>::fetch_more_tokens
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_38_0_edwards25519_scalarmuldouble
 0.1%   0.2%  25.8KiB              prek prek::cli::try_repo::try_repo::{{closure}}
 0.1%   0.2%  24.9KiB             prek? <prek::config::_::<impl serde_core::de::Deserialize for prek::config::Config>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map
 0.1%   0.2%  24.0KiB               std core::ptr::drop_in_place<prek::languages::<impl prek::config::Language>::install::{{closure}}>
 0.1%   0.2%  23.2KiB              prek prek::hooks::meta_hooks::MetaHooks::run::{{closure}}
 0.1%   0.2%  22.4KiB      serde_saphyr saphyr_parser_bw::scanner::Scanner<T>::fetch_more_tokens
 0.1%   0.2%  22.3KiB         [Unknown] Lp384_montjscalarmul_alt_p384_montjadd
 0.1%   0.2%  21.6KiB              prek prek::workspace::Project::init_hooks::{{closure}}
41.0%  85.8%  10.2MiB                   And 23303 smaller methods. Use -n N to show more.
47.8% 100.0%  11.9MiB                   .text section size, the file size is 24.8MiB

Base Branch Results

 File  .text     Size             Crate Name
 1.3%   2.7% 332.0KiB        aws_lc_sys aws_lc_0_38_0_aes_gcm_encrypt_avx512
 1.3%   2.7% 332.0KiB        aws_lc_sys aws_lc_0_38_0_aes_gcm_decrypt_avx512
 0.3%   0.6%  77.0KiB              prek prek::languages::<impl prek::config::Language>::run::{{closure}}::{{closure}}
 0.3%   0.6%  69.8KiB              prek prek::languages::<impl prek::config::Language>::run::{{closure}}::{{closure}}
 0.3%   0.6%  68.0KiB             prek? <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  51.0KiB annotate_snippets annotate_snippets::renderer::render::render
 0.2%   0.4%  50.6KiB              prek prek::languages::<impl prek::config::Language>::install::{{closure}}
 0.2%   0.4%  46.8KiB              prek prek::run::{{closure}}
 0.2%   0.3%  41.8KiB              prek prek::cli::run::run::run::{{closure}}
 0.1%   0.3%  32.0KiB             prek? <prek::cli::RunArgs as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_38_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.8KiB      serde_saphyr saphyr_parser_bw::scanner::Scanner<T>::fetch_more_tokens
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_38_0_edwards25519_scalarmuldouble
 0.1%   0.2%  25.8KiB              prek prek::cli::try_repo::try_repo::{{closure}}
 0.1%   0.2%  24.9KiB             prek? <prek::config::_::<impl serde_core::de::Deserialize for prek::config::Config>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map
 0.1%   0.2%  23.0KiB              prek prek::hooks::meta_hooks::MetaHooks::run::{{closure}}
 0.1%   0.2%  22.4KiB      serde_saphyr saphyr_parser_bw::scanner::Scanner<T>::fetch_more_tokens
 0.1%   0.2%  22.3KiB         [Unknown] Lp384_montjscalarmul_alt_p384_montjadd
 0.1%   0.2%  22.0KiB               std core::ptr::drop_in_place<prek::languages::<impl prek::config::Language>::install::{{closure}}>
 0.1%   0.2%  21.6KiB              prek prek::workspace::Project::init_hooks::{{closure}}
41.1%  86.0%  10.2MiB                   And 23261 smaller methods. Use -n N to show more.
47.8% 100.0%  11.8MiB                   .text section size, the file size is 24.7MiB

prek-ci-bot · 2026-03-12T15:45:32Z

⚡️ Hyperfine Benchmarks

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

Environment

OS: Linux 6.14.0-1017-azure
CPU: 4 cores
prek version: prek 0.3.5+36 (d9115b3 2026-03-13)
Rust version: rustc 1.94.0 (4a4ef493e 2026-03-02)
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	2.9	1.01 ± 0.08
`prek-head --version`	2.3 ± 0.1	2.2	3.4	1.00

`prek list`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base list`	8.8 ± 0.1	8.6	9.1	1.00
`prek-head list`	8.8 ± 0.1	8.6	9.4	1.00 ± 0.02

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

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base validate-config .pre-commit-config.yaml`	3.1 ± 0.2	3.0	4.4	1.00
`prek-head validate-config .pre-commit-config.yaml`	3.1 ± 0.3	3.0	5.1	1.00 ± 0.12

`prek sample-config`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base sample-config`	2.6 ± 0.1	2.5	3.0	1.00
`prek-head sample-config`	2.6 ± 0.1	2.5	2.8	1.01 ± 0.03

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`	149.0 ± 3.5	144.8	154.7	1.00
`prek-head run --all-files`	149.3 ± 2.1	146.9	153.0	1.00 ± 0.03

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

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run --all-files`	150.0 ± 2.4	146.7	156.4	1.00 ± 0.02
`prek-head run --all-files`	149.8 ± 2.3	144.8	153.7	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`	150.2 ± 1.9	147.1	156.1	1.00
`prek-head run --all-files`	155.4 ± 32.2	147.2	377.7	1.03 ± 0.22

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`	21.4 ± 0.4	20.8	22.3	1.00
`prek-head run trailing-whitespace --all-files`	21.4 ± 0.4	20.7	22.3	1.00 ± 0.03

`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`	28.4 ± 2.2	25.2	33.8	1.03 ± 0.10
`prek-head run end-of-file-fixer --all-files`	27.6 ± 1.8	25.1	31.8	1.00

`prek run check-json --all-files`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run check-json --all-files`	12.2 ± 0.4	11.7	13.2	1.01 ± 0.04
`prek-head run check-json --all-files`	12.1 ± 0.2	11.7	12.6	1.00

`prek run check-yaml --all-files`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run check-yaml --all-files`	11.9 ± 0.3	11.6	13.0	1.01 ± 0.03
`prek-head run check-yaml --all-files`	11.8 ± 0.2	11.6	12.3	1.00

`prek run check-toml --all-files`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run check-toml --all-files`	12.1 ± 0.3	11.6	12.9	1.01 ± 0.03
`prek-head run check-toml --all-files`	12.1 ± 0.3	11.6	12.6	1.00

`prek run check-xml --all-files`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run check-xml --all-files`	12.0 ± 0.4	11.4	12.8	1.00
`prek-head run check-xml --all-files`	12.1 ± 0.3	11.5	12.7	1.01 ± 0.04

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`	4.7 ± 0.1	4.7	4.8	1.00
`prek-head install-hooks`	4.8 ± 0.1	4.7	4.9	1.01 ± 0.02

`prek install-hooks (warm - with cache)`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base install-hooks`	4.7 ± 0.1	4.7	4.8	1.00
`prek-head install-hooks`	4.8 ± 0.1	4.7	4.9	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`	18.6 ± 0.1	18.4	18.9	1.01 ± 0.01
`prek-head run`	18.5 ± 0.1	18.2	18.8	1.00

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

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run --files '*.json'`	7.5 ± 0.1	7.3	7.6	1.00
`prek-head run --files '*.json'`	7.5 ± 0.1	7.3	7.7	1.01 ± 0.02

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`	12.3 ± 0.1	12.1	12.7	1.00 ± 0.01
`prek-head run --dry-run --all-files`	12.3 ± 0.1	12.1	12.6	1.00

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`	12.8 ± 0.4	12.4	14.1	1.02 ± 0.03
`prek-head run check-hooks-apply --all-files`	12.5 ± 0.1	12.3	12.7	1.00

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

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run check-useless-excludes --all-files`	12.6 ± 0.2	12.3	13.2	1.00 ± 0.02
`prek-head run check-useless-excludes --all-files`	12.5 ± 0.1	12.4	12.8	1.00

`prek run identity --all-files`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`prek-base run identity --all-files`	11.1 ± 0.3	10.9	12.2	1.01 ± 0.03
`prek-head run identity --all-files`	11.0 ± 0.1	10.9	11.2	1.00

Copilot

Pull request overview

Adds first-class .NET (language: dotnet) support to prek, including SDK selection via language_version, tool installation via additional_dependencies, documentation updates, and CI wiring to run the new language test suite.

Changes:

Implement dotnet language: SDK discovery/download + dotnet tool install --tool-path dependency support.
Add unit + integration tests for dotnet behavior and wire dotnet into language test matrix.
Update docs and nextest profiles to reflect supported dotnet hooks.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
docs/languages.md	Documents dotnet language support, `language_version`, and `additional_dependencies`.
crates/prek/tests/run.rs	Updates an invalid-config test now that dotnet supports deps (uses swift instead).
crates/prek/tests/languages/main.rs	Registers the new dotnet language test module.
crates/prek/tests/languages/dotnet.rs	Adds end-to-end integration tests for dotnet hooks, versions, deps, and error handling.
crates/prek/tests/common/mod.rs	Adds an insta output filter intended for dotnet version output.
crates/prek/src/store.rs	Adds `ToolBucket::Dotnet` for tool storage.
crates/prek/src/languages/version.rs	Adds `LanguageRequest::Dotnet` parsing/satisfaction plumbing.
crates/prek/src/languages/mod.rs	Wires dotnet into supported languages, tool buckets, version support, install/run/health dispatch.
crates/prek/src/languages/dotnet/version.rs	Implements dotnet `language_version` parsing and matching (major / major.minor / exact / `netX.Y`).
crates/prek/src/languages/dotnet/mod.rs	Adds the dotnet language module exports.
crates/prek/src/languages/dotnet/installer.rs	Implements system discovery + managed install via dotnet-install scripts.
crates/prek/src/languages/dotnet/dotnet.rs	Implements hook install/run/health-check and dependency installation for dotnet hooks.
crates/prek-consts/src/env_vars.rs	Adds `DOTNET_ROOT` env var constant.
.github/workflows/ci.yml	Installs .NET in CI for the dotnet language matrix entry.
.config/nextest.toml	Adds a `lang-dotnet` nextest profile to run dotnet language tests.

snus-kin · 2026-03-13T17:50:49Z

crates/prek/src/languages/dotnet/dotnet.rs

+        let env_dir = hook.env_path().expect("Dotnet must have env path");
+        let tool_path = tools_path(env_dir);
+        let dotnet_path = hook
+            .install_info()
+            .expect("Dotnet must have install info")
+            .toolchain
+            .parent()
+            .expect("dotnet executable must have parent");
+
+        // Prepend both dotnet and tools to PATH
+        let new_path = prepend_paths(&[&tool_path, dotnet_path]).context("Failed to join PATH")?;
+        let entry = hook.entry.resolve(Some(&new_path))?;
+
+        let run = async |batch: &[&Path]| {
+            let mut output = Cmd::new(&entry[0], "run dotnet hook")
+                .current_dir(hook.work_dir())
+                .args(&entry[1..])
+                .env(EnvVars::PATH, &new_path)
+                .env(EnvVars::DOTNET_ROOT, dotnet_path)
+                .envs(&hook.env)


This was my fear with dotnet, it's going to be a bit spiky because of stuff like this 🙃 at least CoPilot has a bit of a clue

crates/prek/src/languages/dotnet/dotnet.rs

+async fn install_tool(dotnet: &Path, tool_path: &Path, dependency: &str) -> Result<()> {
+    let (package, version) = dependency
+        .split_once(':')
+        .map_or((dependency, None), |(pkg, ver)| (pkg, Some(ver)));
+


crates/prek/src/languages/dotnet/dotnet.rs

+    cmd.check(true)
+        .output()
+        .await
+        .with_context(|| format!("Failed to install dotnet tool: {dependency}"))?;
+
+    Ok(())


docs/languages.md

+You can request a specific .NET SDK version:
+
+- `language_version: "8"` – any .NET 8.x SDK
+- `language_version: "8.0"` – any .NET 8.0.x SDK
+- `language_version: "8.0.100"` – exactly .NET SDK 8.0.100

-Tracking: [#48](https://github.com/j178/prek/issues/48)
+prek first looks for a matching system-installed `dotnet`, then falls back to downloading the SDK via the official install script if needed.
+
+#### `additional_dependencies`
+
+Tools are specified in `additional_dependencies` using the format `package:version` or `package@version`:
+


crates/prek/tests/languages/dotnet.rs

+/// Test that `language_version` can specify a dotnet SDK version.
+#[test]
+fn language_version() {
+    let context = TestContext::new();
+    context.init_project();
+
+    context.write_pre_commit_config(indoc::indoc! {r"
+        repos:
+          - repo: local
+            hooks:
+              - id: local
+                name: local
+                language: dotnet
+                entry: dotnet --version
+                language_version: '8.0'
+                always_run: true
+                verbose: true
+                pass_filenames: false
+    "});


crates/prek/src/languages/dotnet/installer.rs

+                version.major == *major && version.minor == *minor && version.patch == *patch
+            }
+        },
+        _ => true,
+    }
+}
+
+fn to_dotnet_install_version(request: &LanguageRequest) -> Option<String> {
+    match request {
+        LanguageRequest::Any { .. } => None,
+        LanguageRequest::Dotnet(req) => req.to_install_version(),
+        _ => None,
+    }
+}
+
+/// Add channel arguments to the Unix install command.
+fn add_channel_args_unix(cmd: &mut Cmd, version: Option<&str>) {
+    if let Some(ver) = version {
+        cmd.arg("--channel").arg(ver);
+    } else {
+        // Default to LTS
+        cmd.arg("--channel").arg("LTS");
+    }
+}
+
+/// Add channel arguments to the Windows install command.
+#[cfg(any(windows, test))]
+fn add_channel_args_windows(cmd: &mut Cmd, version: Option<&str>) {
+    if let Some(ver) = version {
+        cmd.arg("-Channel").arg(ver);
+    } else {
+        // Default to LTS
+        cmd.arg("-Channel").arg("LTS");
+    }
+}


crates/prek/tests/common/mod.rs

+    // .NET SDK version output (e.g., "8.0.100" or "9.0.100-preview.1.24101.2")
+    (r"(?m)^\d+\.\d+\.\d+(-[\w.]+)?\n", "[DOTNET_VERSION]\n"),


crates/prek/src/languages/dotnet/installer.rs

+        // Check if we have a managed installation that satisfies the request
+        if let Some(result) = self.find_installed(request).await? {
+            debug!(%result, "Using managed dotnet");
+            return Ok(result);
+        }
+
+        // If system_only is requested and we didn't find a matching system version, fail
+        if matches!(request, LanguageRequest::Any { system_only: true }) {
+            anyhow::bail!("No system dotnet installation found");
+        }
+
+        if !allows_download {
+            anyhow::bail!("No suitable dotnet version found and downloads are disabled");
+        }
+
+        // Install dotnet SDK
+        let version_request = to_dotnet_install_version(request);
+        debug!("Installing dotnet SDK");
+        self.download(version_request.as_deref()).await?;
+
+        self.verify_and_query_installation().await
+    }


crates/prek/src/languages/dotnet/installer.rs

+pub(crate) async fn query_dotnet_version(dotnet: &Path) -> Result<Version> {
+    let stdout = Cmd::new(dotnet, "get dotnet version")
+        .arg("--version")
+        .check(true)
+        .output()
+        .await?
+        .stdout;
+
+    let version_str = String::from_utf8_lossy(&stdout).trim().to_string();
+    parse_dotnet_version(&version_str).context("Failed to parse dotnet version")
+}


Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Adds first-class .NET (dotnet) language support to prek, including SDK version selection and dotnet tool installation for hooks.

Changes:

Implement dotnet language: SDK discovery/download + hook execution environment setup.
Add dotnet-specific tests, nextest profile, and CI setup-dotnet wiring.
Update documentation to describe supported dotnet behavior and configuration options.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
docs/languages.md	Documents dotnet language support, `language_version`, and `additional_dependencies`.
crates/prek/tests/run.rs	Updates an “invalid config” test to use swift instead of dotnet.
crates/prek/tests/languages/main.rs	Registers new dotnet language test module.
crates/prek/tests/languages/dotnet.rs	Adds integration tests for dotnet language behavior.
crates/prek/tests/common/mod.rs	Adds an insta filter for dotnet version output.
crates/prek/src/store.rs	Introduces a `Dotnet` tool bucket for caching/install locations.
crates/prek/src/languages/version.rs	Adds parsing/dispatch for `LanguageRequest::Dotnet`.
crates/prek/src/languages/mod.rs	Wires the dotnet language into install/health/run and capability flags.
crates/prek/src/languages/dotnet/mod.rs	Adds dotnet language module exports.
crates/prek/src/languages/dotnet/version.rs	Implements dotnet SDK version request parsing and matching.
crates/prek/src/languages/dotnet/installer.rs	Implements system discovery + managed SDK download via dotnet-install scripts.
crates/prek/src/languages/dotnet/dotnet.rs	Implements hook install/run logic and dotnet tool installation.
crates/prek-consts/src/env_vars.rs	Adds `DOTNET_ROOT` env var constant.
.github/workflows/ci.yml	Installs dotnet in CI for the dotnet language test matrix entry.
.config/nextest.toml	Adds a nextest profile to run only dotnet language tests.

docs/languages.md

+
+#### `additional_dependencies`
+
+Tools are specified in `additional_dependencies` using the format `package:version` or `package@version`:


crates/prek/src/languages/dotnet/installer.rs

+        let version_request = to_dotnet_install_version(request);
+        debug!("Installing dotnet SDK");
+        self.download(version_request.as_deref()).await?;


crates/prek/src/languages/dotnet/installer.rs

+/// Add channel arguments to the Unix install command.
+fn add_channel_args_unix(cmd: &mut Cmd, version: Option<&str>) {
+    if let Some(ver) = version {
+        cmd.arg("--channel").arg(ver);
+    } else {
+        // Default to LTS
+        cmd.arg("--channel").arg("LTS");
+    }
+}
+
+/// Add channel arguments to the Windows install command.
+#[cfg(any(windows, test))]
+fn add_channel_args_windows(cmd: &mut Cmd, version: Option<&str>) {
+    if let Some(ver) = version {
+        cmd.arg("-Channel").arg(ver);


crates/prek/src/languages/dotnet/installer.rs

+        let response = reqwest::get(script_url)
+            .await
+            .context("Failed to download dotnet-install.ps1")?;
+        let script_content = response
+            .bytes()
+            .await
+            .context("Failed to read dotnet-install.ps1")?;


crates/prek/src/languages/dotnet/dotnet.rs

+    fn dotnet_path() -> std::path::PathBuf {
+        which::which("dotnet").expect("dotnet must be installed to run this test")
+    }


crates/prek/tests/languages/dotnet.rs

crates/prek/tests/common/mod.rs

    // Time seconds
    (r"\b(\d+\.)?\d+(ms|s)\b", "[TIME]"),
+    // .NET SDK version output (e.g., "8.0.100" or "9.0.100-preview.1.24101.2")
+    (r"(?m)^\d+\.\d+\.\d+(-[\w.]+)?\n", "[DOTNET_VERSION]\n"),


Thomas Carroll added 8 commits March 12, 2026 13:48

feat: dotnet support for prek

e6edfed

refactor: split out the installer

38e05a9

fix: use colon as version separator for dotnet dependencies

f00f0de

Use `:" instead of "@" as the version separator in additional_dependencies to match pre-commit convention (e.g., "csharpier:1.2.6").

docs: update dotnet version examples to include net10.0

9397737

test: fix dotnet tests to use colon separator and net10.0

55cd645

test: add .NET SDK version filter for snapshot tests

395b578

docs: update dotnet language documentation to show supported status

6697dab

ci: add dotnet to language test matrix

f86743f

test: adds some more test coverage

eb21beb

Thomas Carroll added 2 commits March 12, 2026 15:59

test: flush stderr

282e99a

test: replace PATH removal with binary shadowing

91e496d

snus-kin force-pushed the feature/dotnet-support branch from 0108fa0 to 9e90893 Compare March 13, 2026 09:57

test: more cov

3a39aac

snus-kin force-pushed the feature/dotnet-support branch from 9e90893 to 3a39aac Compare March 13, 2026 09:58

test: test through LanguageRequest

c44b3ea

snus-kin force-pushed the feature/dotnet-support branch from 2625a90 to c44b3ea Compare March 13, 2026 10:30

Thomas Carroll added 5 commits March 13, 2026 11:10

test: Add check_health and error handling tests

5392ca4

test: Add dotnet LTS download test when no system dotnet

ad2cf2a

test: add dotnet version mismatch and missing executable tests

e2cb2ff

refactor: extract channel argument logic to helper functions

9526a95

refactor: extract dotnet system path validation to separate method

4f3d95f

snus-kin marked this pull request as ready for review March 13, 2026 12:37

snus-kin requested a review from j178 as a code owner March 13, 2026 12:37

Copilot AI review requested due to automatic review settings March 13, 2026 12:37

Copilot started reviewing on behalf of snus-kin March 13, 2026 12:37 View session

Copilot AI reviewed Mar 13, 2026

View reviewed changes

refactor: Use global REQWEST_CLIENT, check response status

a35abb4

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings March 13, 2026 17:52

Copilot started reviewing on behalf of snus-kin March 13, 2026 17:52 View session

Copilot AI reviewed Mar 13, 2026

View reviewed changes

		// .NET SDK version output (e.g., "8.0.100" or "9.0.100-preview.1.24101.2")
		(r"(?m)^\d+\.\d+\.\d+(-[\w.]+)?\n", "[DOTNET_VERSION]\n"),


		#### `additional_dependencies`

		Tools are specified in `additional_dependencies` using the format `package:version` or `package@version`:

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prek --version

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

prek sample-config

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

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

prek run trailing-whitespace --all-files

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

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prek run (staged files only)

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

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

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

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

prek run identity --all-files

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`prek --version`

`prek list`

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

`prek sample-config`

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

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

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

`prek run trailing-whitespace --all-files`

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

`prek run check-json --all-files`

`prek run check-yaml --all-files`

`prek run check-toml --all-files`

`prek run check-xml --all-files`

`prek install-hooks (cold - no cache)`

`prek install-hooks (warm - with cache)`

`prek run (staged files only)`

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

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

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

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

`prek run identity --all-files`