1 files changed, 97 insertions, 0 deletions
diff --git a/pre_commit/languages/dart.py b/pre_commit/languages/dart.py
new file mode 100644
index 0000000..129ac59
--- /dev/null
+++ b/pre_commit/languages/dart.py
@@ -0,0 +1,97 @@
+from __future__ import annotations
+
+import contextlib
+import os.path
+import shutil
+import tempfile
+from collections.abc import Generator
+from collections.abc import Sequence
+
+from pre_commit import lang_base
+from pre_commit.envcontext import envcontext
+from pre_commit.envcontext import PatchesT
+from pre_commit.envcontext import Var
+from pre_commit.prefix import Prefix
+from pre_commit.util import win_exe
+from pre_commit.yaml import yaml_load
+
+ENVIRONMENT_DIR = 'dartenv'
+
+get_default_version = lang_base.basic_get_default_version
+health_check = lang_base.basic_health_check
+run_hook = lang_base.basic_run_hook
+
+
+def get_env_patch(venv: str) -> PatchesT:
+    return (
+        ('PATH', (os.path.join(venv, 'bin'), os.pathsep, Var('PATH'))),
+    )
+
+
+@contextlib.contextmanager
+def in_env(prefix: Prefix, version: str) -> Generator[None, None, None]:
+    envdir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
+    with envcontext(get_env_patch(envdir)):
+        yield
+
+
+def install_environment(
+        prefix: Prefix,
+        version: str,
+        additional_dependencies: Sequence[str],
+) -> None:
+    lang_base.assert_version_default('dart', version)
+
+    envdir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
+    bin_dir = os.path.join(envdir, 'bin')
+
+    def _install_dir(prefix_p: Prefix, pub_cache: str) -> None:
+        dart_env = {**os.environ, 'PUB_CACHE': pub_cache}
+
+        with open(prefix_p.path('pubspec.yaml')) as f:
+            pubspec_contents = yaml_load(f)
+
+        lang_base.setup_cmd(prefix_p, ('dart', 'pub', 'get'), env=dart_env)
+
+        for executable in pubspec_contents['executables']:
+            lang_base.setup_cmd(
+                prefix_p,
+                (
+                    'dart', 'compile', 'exe',
+                    '--output', os.path.join(bin_dir, win_exe(executable)),
+                    prefix_p.path('bin', f'{executable}.dart'),
+                ),
+                env=dart_env,
+            )
+
+    os.makedirs(bin_dir)
+
+    with tempfile.TemporaryDirectory() as tmp:
+        _install_dir(prefix, tmp)
+
+    for dep_s in additional_dependencies:
+        with tempfile.TemporaryDirectory() as dep_tmp:
+            dep, _, version = dep_s.partition(':')
+            if version:
+                dep_cmd: tuple[str, ...] = (dep, '--version', version)
+            else:
+                dep_cmd = (dep,)
+
+            lang_base.setup_cmd(
+                prefix,
+                ('dart', 'pub', 'cache', 'add', *dep_cmd),
+                env={**os.environ, 'PUB_CACHE': dep_tmp},
+            )
+
+            # try and find the 'pubspec.yaml' that just got added
+            for root, _, filenames in os.walk(dep_tmp):
+                if 'pubspec.yaml' in filenames:
+                    with tempfile.TemporaryDirectory() as copied:
+                        pkg = os.path.join(copied, 'pkg')
+                        shutil.copytree(root, pkg)
+                        _install_dir(Prefix(pkg), dep_tmp)
+                    break
+            else:
+                raise AssertionError(
+                    f'could not find pubspec.yaml for {dep_s}',
+                )