Fix file content check to handle missing files

src/pyinfra/facts/files.py

@@ -398,7 +398,7 @@ def process(self, output) -> Optional[str]:
 class Sha1File(HashFileFactBase, digits=40, cmds=["sha1sum", "shasum", "sha1"]):
     """
     Returns a SHA1 hash of a file. Works with both sha1sum and sha1. Returns
-    ``None`` if the file doest not exist.
+    ``None`` if the file does not exist.
     """
 
 
@@ -664,14 +664,16 @@ def process(self, output):
 
 class FileContents(FactBase):
     """
-    Returns the contents of a file as a list of lines. Works with both sha1sum and sha1. Returns
-    ``None`` if the file doest not exist.
+    Returns the contents of a file as a list of lines. Returns
+    ``None`` if the file does not exist.
     """
 
     @override
     def command(self, path):
-        return make_formatted_string_command("cat {0}", QuoteString(path))
+        return make_formatted_string_command("test -e {0} && cat {0} || true", QuoteString(path))
 
     @override
     def process(self, output):
+        if not output:
+            return self.default()
         return output

tests/facts/files.FileContents/file.json

@@ -1,6 +1,6 @@
 {
     "arg": "myfile",
-    "command": "cat myfile",
+    "command": "test -e myfile && cat myfile || true",
     "output": ["line1", "line2"],
     "fact": ["line1", "line2"]
 }

tests/facts/files.FileContents/no_file.json

@@ -1,6 +1,6 @@
 {
     "arg": ["test"],
-    "command": "cat test",
-    "output": null,
+    "command": "test -e test && cat test || true",
+    "output": [],
     "fact": null
 }