pre-commit · ericphanson · Jul 21, 2025 · Jul 21, 2025 · Jul 21, 2025 · Jul 21, 2025
diff --git a/.github/workflows/languages.yaml b/.github/workflows/languages.yaml
@@ -67,7 +67,12 @@ jobs:
       if: matrix.language == 'haskell'
     - uses: r-lib/actions/setup-r@v2
       if: matrix.os == 'ubuntu-latest' && matrix.language == 'r'
-
+    - uses: julia-actions/install-juliaup@v2
+      if: matrix.language == 'julia'
+      with:
+        channel: 'release'
+    - run: juliaup add 1.10.10
+      if: matrix.language == 'julia'
     - name: install deps
       run: python -mpip install -e . -r requirements-dev.txt
     - name: run tests

diff --git a/pre_commit/languages/julia.py b/pre_commit/languages/julia.py
@@ -37,7 +37,7 @@ def run_hook(
 
     cmd = lang_base.hook_cmd(entry, args)
     script = cmd[0] if is_local else prefix.path(cmd[0])
-    cmd = ('julia', script, *cmd[1:])
+    cmd = ('julia', '--startup-file=no', script, *cmd[1:])
     return lang_base.run_xargs(
         cmd,
         file_args,
@@ -47,11 +47,17 @@ def run_hook(
 
 
 def get_env_patch(target_dir: str, version: str) -> PatchesT:
-    return (
+    patches = (
         ('JULIA_LOAD_PATH', target_dir),
-        # May be set, remove it to not interfer with LOAD_PATH
+        # May be set, remove it to not interfere with LOAD_PATH
         ('JULIA_PROJECT', UNSET),
+        # Only set JULIAUP_CHANNEL if we don't want use the system's default
+        *(
+            (('JULIAUP_CHANNEL', version),)
+            if version not in ('system', 'default') else ()
+        ),
     )
+    return patches
 
 
 @contextlib.contextmanager
@@ -68,10 +74,6 @@ def install_environment(
 ) -> None:
     envdir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
     with in_env(prefix, version):
-        # TODO: Support language_version with juliaup similar to rust via
-        # rustup
-        # if version != 'system':
-        #     ...
 
         # Copy Project.toml to hook env if it exist
         os.makedirs(envdir, exist_ok=True)
@@ -99,6 +101,14 @@ def install_environment(
             shutil.copy(manifest_file, envdir)
             break
 
+        # copy `src` files if they exist
+        src_dir = prefix.path('src')
+        if os.path.isdir(src_dir):
+            shutil.copytree(
+                src_dir, os.path.join(envdir, 'src'),
+                dirs_exist_ok=True,
+            )
+
         # Julia code to instantiate the hook environment
         julia_code = """
         @assert length(ARGS) > 0
@@ -127,6 +137,6 @@ def install_environment(
         end
         """
         cmd_output_b(
-            'julia', '-e', julia_code, '--', envdir, *additional_dependencies,
-            cwd=prefix.prefix_dir,
+            'julia', '--startup-file=no', '-e', julia_code, '--', envdir,
+            *additional_dependencies, cwd=prefix.prefix_dir,
         )
diff --git a/tests/languages/julia_test.py b/tests/languages/julia_test.py
@@ -28,6 +28,22 @@ def test_julia_hook(tmp_path):
     assert run_language(tmp_path, julia, 'src/main.jl') == expected
 
 
+def test_julia_hook_version(tmp_path):
+    code = """
+    using Example
+    function main()
+        println("Hello, Julia $(VERSION)!")
+    end
+    main()
+    """
+    _make_hook(tmp_path, code)
+    expected = (0, b'Hello, Julia 1.10.10!\n')
+    assert run_language(
+        tmp_path, julia, 'src/main.jl',
+        version='1.10.10',
+    ) == expected
+
+
 def test_julia_hook_manifest(tmp_path):
     code = """
     using Example
@@ -95,3 +111,41 @@ def test_julia_repo_local(tmp_path):
             env_dir, julia, 'local.jl --local-arg1 --local-arg2',
             deps=deps, is_local=True,
         ) == expected
+
+
+def _make_src_hook(tmp_path, pkg_code, script_code):
+    # here we have a package with a src dir and a script dir
+    src_dir = tmp_path.joinpath('src')
+    src_dir.mkdir()
+    src_dir.joinpath('ExamplePkg.jl').write_text(pkg_code)
+
+    script_dir = tmp_path.joinpath('scripts')
+    script_dir.mkdir()
+    script_dir.joinpath('main.jl').write_text(script_code)
+
+    tmp_path.joinpath('Project.toml').write_text(
+        'name = "ExamplePkg"\n'
+        'uuid = "df230c44-b485-4b6a-bafb-763c50abe554"\n'
+        '[deps]\n'
+        'Example = "7876af07-990d-54b4-ab0e-23690620f79a"\n',
+    )
+
+
+def test_julia_hook_src(tmp_path):
+    pkg_code = """
+    module ExamplePkg
+    using Example
+    export main
+    function main()
+        println("Hello, world!")
+    end
+    end
+    """
+
+    script_code = """
+    using ExamplePkg
+    main()
+    """
+    _make_src_hook(tmp_path, pkg_code, script_code)
+    expected = (0, b'Hello, world!\n')
+    assert run_language(tmp_path, julia, 'scripts/main.jl') == expected