1 files changed, 33 insertions, 38 deletions

diff --git a/pre_commit/languages/coursier.py b/pre_commit/languages/coursier.py
index 9fe43eb..6075758 100644
--- a/pre_commit/languages/coursier.py
+++ b/pre_commit/languages/coursier.py
@@ -1,81 +1,76 @@
 from __future__ import annotations
 
 import contextlib
-import os
+import os.path
 from typing import Generator
 from typing import Sequence
 
 from pre_commit.envcontext import envcontext
 from pre_commit.envcontext import PatchesT
 from pre_commit.envcontext import Var
-from pre_commit.hook import Hook
+from pre_commit.errors import FatalError
 from pre_commit.languages import helpers
 from pre_commit.parse_shebang import find_executable
 from pre_commit.prefix import Prefix
-from pre_commit.util import clean_path_on_failure
 
 ENVIRONMENT_DIR = 'coursier'
 
 get_default_version = helpers.basic_get_default_version
 health_check = helpers.basic_health_check
+run_hook = helpers.basic_run_hook
 
 
 def install_environment(
         prefix: Prefix,
         version: str,
         additional_dependencies: Sequence[str],
-) -> None:   # pragma: win32 no cover
+) -> None:
     helpers.assert_version_default('coursier', version)
-    helpers.assert_no_additional_deps('coursier', additional_dependencies)
 
     # Support both possible executable names (either "cs" or "coursier")
-    executable = find_executable('cs') or find_executable('coursier')
-    if executable is None:
+    cs = find_executable('cs') or find_executable('coursier')
+    if cs is None:
         raise AssertionError(
             'pre-commit requires system-installed "cs" or "coursier" '
             'executables in the application search path',
         )
 
-    envdir = prefix.path(helpers.environment_dir(ENVIRONMENT_DIR, version))
-    channel = prefix.path('.pre-commit-channel')
-    with clean_path_on_failure(envdir):
-        for app_descriptor in os.listdir(channel):
-            _, app_file = os.path.split(app_descriptor)
-            app, _ = os.path.splitext(app_file)
-            helpers.run_setup_cmd(
-                prefix,
-                (
-                    executable,
-                    'install',
+    envdir = helpers.environment_dir(prefix, ENVIRONMENT_DIR, version)
+
+    def _install(*opts: str) -> None:
+        assert cs is not None
+        helpers.run_setup_cmd(prefix, (cs, 'fetch', *opts))
+        helpers.run_setup_cmd(prefix, (cs, 'install', '--dir', envdir, *opts))
+
+    with in_env(prefix, version):
+        channel = prefix.path('.pre-commit-channel')
+        if os.path.isdir(channel):
+            for app_descriptor in os.listdir(channel):
+                _, app_file = os.path.split(app_descriptor)
+                app, _ = os.path.splitext(app_file)
+                _install(
                     '--default-channels=false',
-                    f'--channel={channel}',
+                    '--channel', channel,
                     app,
-                    f'--dir={envdir}',
-                ),
+                )
+        elif not additional_dependencies:
+            raise FatalError(
+                'expected .pre-commit-channel dir or additional_dependencies',
             )
 
+        if additional_dependencies:
+            _install(*additional_dependencies)
 
-def get_env_patch(target_dir: str) -> PatchesT:   # pragma: win32 no cover
+
+def get_env_patch(target_dir: str) -> PatchesT:
     return (
         ('PATH', (target_dir, os.pathsep, Var('PATH'))),
+        ('COURSIER_CACHE', os.path.join(target_dir, '.cs-cache')),
     )
 
 
 @contextlib.contextmanager
-def in_env(
-        prefix: Prefix,
-) -> Generator[None, None, None]:   # pragma: win32 no cover
-    target_dir = prefix.path(
-        helpers.environment_dir(ENVIRONMENT_DIR, get_default_version()),
-    )
-    with envcontext(get_env_patch(target_dir)):
+def in_env(prefix: Prefix, version: str) -> Generator[None, None, None]:
+    envdir = helpers.environment_dir(prefix, ENVIRONMENT_DIR, version)
+    with envcontext(get_env_patch(envdir)):
         yield
-
-
-def run_hook(
-        hook: Hook,
-        file_args: Sequence[str],
-        color: bool,
-) -> tuple[int, bytes]:   # pragma: win32 no cover
-    with in_env(hook.prefix):
-        return helpers.run_xargs(hook, hook.cmd, file_args, color=color)