From 4b515d98ba83252a9acecb1bc9b02d9b1df599df Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 24 Sep 2026 15:35:25 +0000
Subject: [PATCH 1/3] Initial plan


From 9a8f682802a11b9f26ee23b9d0ed7d5218879498 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 24 Sep 2026 15:38:18 +0000
Subject: [PATCH 2/3] Add .env support for mounted directory

Co-authored-by: dmalan <788678+dmalan@users.noreply.github.com>
---
 cli50/__main__.py | 30 ++++++++++++++++++++++++++++++
 tests/test_env.py | 22 ++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 tests/test_env.py

diff --git a/cli50/__main__.py b/cli50/__main__.py
index ee300c5..b462845 100644
--- a/cli50/__main__.py
+++ b/cli50/__main__.py
@@ -221,6 +221,12 @@ def main():
     if lang := os.getenv("LANG"):
         options += ["--env", f"LANG={lang}"]
 
+    # Check for .env
+    try:
+        options += env_options(directory)
+    except RuntimeError as e:
+        sys.exit(_("{}: unable to source").format(e))
+
     # Validate ports
     if not args["port"]:
         args["port"] = PORTS
@@ -321,6 +327,30 @@ def ports(container):
     return ", ".join(mappings)
 
 
+def env_options(directory):
+    """Return Docker options for .env in directory."""
+    dotenv = os.path.join(directory, ".env")
+    if not os.path.isfile(dotenv):
+        return []
+    try:
+        before = subprocess.check_output([
+            "bash", "-c", "env -0"
+        ], env={}, cwd=directory).decode("utf-8")
+        after = subprocess.check_output([
+            "bash", "-c", 'set -a && source "$1" && env -0', "_", dotenv
+        ], env={}, cwd=directory).decode("utf-8")
+    except subprocess.CalledProcessError:
+        raise RuntimeError(dotenv) from None
+
+    before = dict(entry.split("=", 1) for entry in before.rstrip("\0").split("\0") if entry)
+    after = dict(entry.split("=", 1) for entry in after.rstrip("\0").split("\0") if entry)
+    options = []
+    for key, value in after.items():
+        if before.get(key) != value:
+            options += ["--env", f"{key}={value}"]
+    return options
+
+
 def pull(image, tag):
     """Pull image as needed."""
     import json
diff --git a/tests/test_env.py b/tests/test_env.py
new file mode 100644
index 0000000..4ffff29
--- /dev/null
+++ b/tests/test_env.py
@@ -0,0 +1,22 @@
+import os
+import tempfile
+import unittest
+
+from cli50.__main__ import env_options
+
+
+def env_dict(options):
+    return dict(option.split("=", 1) for option in options[1::2])
+
+
+class EnvOptionsTestCase(unittest.TestCase):
+
+    def test_env_options_sources_dotenv(self):
+        with tempfile.TemporaryDirectory() as directory:
+            with open(os.path.join(directory, ".env"), "w") as file:
+                file.write("FOO=bar\nexport BAZ='qux quux'\n")
+            self.assertEqual(env_dict(env_options(directory)), {"FOO": "bar", "BAZ": "qux quux"})
+
+    def test_env_options_ignores_missing_dotenv(self):
+        with tempfile.TemporaryDirectory() as directory:
+            self.assertEqual(env_options(directory), [])

From ca00d09042e4be921633f7b4c6ad1fc6a6be8557 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 24 Sep 2026 15:53:48 +0000
Subject: [PATCH 3/3] Address PR feedback on .env change

Co-authored-by: dmalan <788678+dmalan@users.noreply.github.com>
---
 cli50/__main__.py |  5 +++++
 tests/test_env.py | 22 ----------------------
 2 files changed, 5 insertions(+), 22 deletions(-)
 delete mode 100644 tests/test_env.py

diff --git a/cli50/__main__.py b/cli50/__main__.py
index b462845..46587d5 100644
--- a/cli50/__main__.py
+++ b/cli50/__main__.py
@@ -223,6 +223,7 @@ def main():
 
     # Check for .env
     try:
+        # Source and export any variables from DIRECTORY/.env.
         options += env_options(directory)
     except RuntimeError as e:
         sys.exit(_("{}: unable to source").format(e))
@@ -333,9 +334,13 @@ def env_options(directory):
     if not os.path.isfile(dotenv):
         return []
     try:
+        # Capture bash's baseline environment so shell defaults like PWD
+        # are not forwarded unless DIRECTORY/.env actually changes them.
         before = subprocess.check_output([
             "bash", "-c", "env -0"
         ], env={}, cwd=directory).decode("utf-8")
+
+        # Source and export DIRECTORY/.env, then emit the resulting environment.
         after = subprocess.check_output([
             "bash", "-c", 'set -a && source "$1" && env -0', "_", dotenv
         ], env={}, cwd=directory).decode("utf-8")
diff --git a/tests/test_env.py b/tests/test_env.py
deleted file mode 100644
index 4ffff29..0000000
--- a/tests/test_env.py
+++ /dev/null
@@ -1,22 +0,0 @@
-import os
-import tempfile
-import unittest
-
-from cli50.__main__ import env_options
-
-
-def env_dict(options):
-    return dict(option.split("=", 1) for option in options[1::2])
-
-
-class EnvOptionsTestCase(unittest.TestCase):
-
-    def test_env_options_sources_dotenv(self):
-        with tempfile.TemporaryDirectory() as directory:
-            with open(os.path.join(directory, ".env"), "w") as file:
-                file.write("FOO=bar\nexport BAZ='qux quux'\n")
-            self.assertEqual(env_dict(env_options(directory)), {"FOO": "bar", "BAZ": "qux quux"})
-
-    def test_env_options_ignores_missing_dotenv(self):
-        with tempfile.TemporaryDirectory() as directory:
-            self.assertEqual(env_options(directory), [])