From 10b4357e5193b0aa05a08137577ae92476c0bb23 Mon Sep 17 00:00:00 2001
From: Sriram Madapusi Vasudevan <3770774+TheSriram@users.noreply.github.com>
Date: Wed, 20 Nov 2019 12:30:21 -0800
Subject: [PATCH] fix: only create config file on write (#1559)

---
 samcli/lib/config/samconfig.py          | 12 +++++++-----
 tests/unit/lib/config/test_samconfig.py |  6 +++++-
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/samcli/lib/config/samconfig.py b/samcli/lib/config/samconfig.py
index 4ca390c9e7..f2fb8d7dce 100644
--- a/samcli/lib/config/samconfig.py
+++ b/samcli/lib/config/samconfig.py
@@ -36,8 +36,6 @@ def __init__(self, config_dir, filename=None):
             could automatically support auto-resolving multiple config files within same directory.
         """
         self.filepath = Path(config_dir, filename or DEFAULT_CONFIG_FILE_NAME)
-        if not self.filepath.exists():
-            open(self.filepath, "a+").close()
 
     def get_all(self, cmd_names, section, env=DEFAULT_ENV):
         """
@@ -153,15 +151,19 @@ def _read(self):
         if self.document:
             return self.document
 
-        txt = self.filepath.read_text()
-        self.document = tomlkit.loads(txt)
+        try:
+            txt = self.filepath.read_text()
+            self.document = tomlkit.loads(txt)
+        except OSError:
+            self.document = tomlkit.document()
 
         return self.document
 
     def _write(self):
         if not self.document:
             return
-
+        if not self.exists():
+            open(self.filepath, "a+").close()
         self.filepath.write_text(tomlkit.dumps(self.document))
 
     @staticmethod
diff --git a/tests/unit/lib/config/test_samconfig.py b/tests/unit/lib/config/test_samconfig.py
index c39e8f494d..54575c1198 100644
--- a/tests/unit/lib/config/test_samconfig.py
+++ b/tests/unit/lib/config/test_samconfig.py
@@ -10,7 +10,6 @@ class TestSamConfig(TestCase):
     def setUp(self):
         self.config_dir = os.getcwd()
         self.samconfig = SamConfig(self.config_dir)
-        open(self.samconfig.path(), "w").close()
 
     def tearDown(self):
         if self.samconfig.exists():
@@ -19,6 +18,8 @@ def tearDown(self):
     def _setup_config(self):
         self.samconfig.put(cmd_names=["local", "start", "api"], section="parameters", key="port", value=5401)
         self.samconfig.flush()
+        self.assertTrue(self.samconfig.exists())
+        self.assertTrue(self.samconfig.sanity_check())
 
     def test_init(self):
         self.assertEqual(self.samconfig.filepath, Path(self.config_dir, DEFAULT_CONFIG_FILE_NAME))
@@ -32,3 +33,6 @@ def test_check_config_get(self):
     def test_check_config_exists(self):
         self._setup_config()
         self.assertTrue(self.samconfig.exists())
+
+    def test_check_sanity(self):
+        self.assertTrue(self.samconfig.sanity_check())