Add info when using 'find' without path

ShellCheck/Checks/Commands.hs

@@ -91,6 +91,7 @@ commandChecks = [
     ,checkAliasesUsesArgs
     ,checkAliasesExpandEarly
     ,checkUnsetGlobs
+    ,checkFindWithoutPath
     ]
 
 buildCommandMap :: [CommandCheck] -> Map.Map CommandName (Token -> Analysis)
@@ -599,5 +600,24 @@ checkUnsetGlobs = CommandCheck (Exactly "unset") (mapM_ check . arguments)
             warn (getId arg) 2184 "Quote arguments to unset so they're not glob expanded."
 
 
+prop_checkFindWithoutPath1 = verify checkFindWithoutPath "find -type f"
+prop_checkFindWithoutPath2 = verify checkFindWithoutPath "find"
+prop_checkFindWithoutPath3 = verifyNot checkFindWithoutPath "find . -type f"
+prop_checkFindWithoutPath4 = verifyNot checkFindWithoutPath "find -H -L \"$path\" -print"
+checkFindWithoutPath = CommandCheck (Basename "find") f
+  where
+    f (T_SimpleCommand _ _ (cmd:args)) =
+        unless (hasPath args) $
+            info (getId cmd) 2185 "Some finds don't have a default path. Specify '.' explicitly."
+
+    -- This is a bit of a kludge. find supports flag arguments both before and after the path,
+    -- as well as multiple non-flag arguments that are not the path. We assume that all the
+    -- pre-path flags are single characters, which is generally the case.
+    hasPath (first:rest) =
+        let flag = fromJust $ getLiteralStringExt (const $ return "___") first in
+            not ("-" `isPrefixOf` flag) || length flag <= 2 && hasPath rest
+    hasPath [] = False
+
+
 return []
 runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])