diff --git a/tests/host/Makefile b/tests/host/Makefile
index 37ee1e841..e0a3e143b 100644
--- a/tests/host/Makefile
+++ b/tests/host/Makefile
@@ -75,14 +75,14 @@ gcov: test
 	find $(CORE_PATH) -name "*.gcno" -exec $(GCOV) -r -pb {} +
 
 build-info:
-	echo "-------- build tools info --------"
-	echo "CC: " $(CC)
+	@echo "-------- build tools info --------"
+	@echo "CC: " $(CC)
 	$(CC) -v
-	echo "CXX: " $(CXX)
+	@echo "CXX: " $(CXX)
 	$(CXX) -v
-	echo "GCOV: " $(GCOV)
+	@echo "GCOV: " $(GCOV)
 	$(GCOV) -v
-	echo "----------------------------------"
+	@echo "----------------------------------"
 
 $(BINARY_DIRECTORY):
 	mkdir -p $@
diff --git a/tests/host/fs/test_fs.cpp b/tests/host/fs/test_fs.cpp
index f49b3fc67..ad5e9fd65 100644
--- a/tests/host/fs/test_fs.cpp
+++ b/tests/host/fs/test_fs.cpp
@@ -1,43 +1,82 @@
 /*
  test_fs.cpp - host side file system tests
  Copyright © 2016 Ivan Grokhotkov
- 
+
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
- 
+
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
 */
 
 #include <catch.hpp>
+#include <map>
 #include <FS.h>
 #include "../common/spiffs_mock.h"
+#include <spiffs/spiffs.h>
 
+static void createFile (const char* name, const char* content)
+{
+    auto f = SPIFFS.open(name, "w");
+    REQUIRE(f);
+    if (content) {
+        f.print(content);
+    }
+}
+
+static String readFile (const char* name)
+{
+    auto f = SPIFFS.open(name, "r");
+    if (f) {
+        return f.readString();
+    }
+    return String();
+}
+
+static std::set<String> listDir (const char* path)
+{
+    std::set<String> result;
+    Dir dir = SPIFFS.openDir(path);
+    while (dir.next()) {
+        REQUIRE(result.find(dir.fileName()) == std::end(result));
+        result.insert(dir.fileName());
+    }
+    return result;
+}
 
 TEST_CASE("FS can begin","[fs]")
 {
-    SPIFFS_MOCK_DECLARE(1024, 8, 512);
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
     REQUIRE(SPIFFS.begin());
 }
 
+TEST_CASE("FS can't begin with zero size","[fs]")
+{
+    SPIFFS_MOCK_DECLARE(0, 8, 512);
+    REQUIRE_FALSE(SPIFFS.begin());
+}
+
+TEST_CASE("Before begin is called, open will fail","[fs]")
+{
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
+    REQUIRE_FALSE(SPIFFS.open("/foo", "w"));
+}
+
 TEST_CASE("FS can create file","[fs]")
 {
-    SPIFFS_MOCK_DECLARE(1024, 8, 512);
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
     REQUIRE(SPIFFS.begin());
-    {
-        File f = SPIFFS.open("config.txt", "w");
-        REQUIRE(f);
-    }
-    REQUIRE(SPIFFS.exists("config.txt"));
+    createFile("/test", "");
+    REQUIRE(SPIFFS.exists("/test"));
 }
 
 TEST_CASE("Files can be written and appended to","[fs]")
 {
-    SPIFFS_MOCK_DECLARE(1024, 8, 512);
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
     REQUIRE(SPIFFS.begin());
     {
         File f = SPIFFS.open("config1.txt", "w");
@@ -61,20 +100,76 @@ TEST_CASE("Files can be written and appended to","[fs]")
 
 TEST_CASE("Files persist after reset", "[fs]")
 {
-    SPIFFS_MOCK_DECLARE(1024, 8, 512);
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
     REQUIRE(SPIFFS.begin());
-    {
-        File f = SPIFFS.open("config1.txt", "w");
-        REQUIRE(f);
-        f.println("file 1");
-    }
+    createFile("config1.txt", "file 1");
+
     SPIFFS_MOCK_RESET();
     REQUIRE(SPIFFS.begin());
-    {
-        File f = SPIFFS.open("config1.txt", "r");
-        REQUIRE(f);
-        REQUIRE(f.readString() == "file 1\r\n");
-    }
+    REQUIRE(readFile("config1.txt") == "file 1");
 }
 
 
+TEST_CASE("Filesystem is empty after format", "[fs]")
+{
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
+    REQUIRE(SPIFFS.format());
+    REQUIRE(SPIFFS.begin());
+    createFile("/1", "first");
+    createFile("/2", "second");
+    REQUIRE(SPIFFS.format());
+    Dir root = SPIFFS.openDir("/");
+    size_t count = 0;
+    while (root.next()) {
+        ++count;
+    }
+    REQUIRE(count == 0);
+}
+
+TEST_CASE("Dir lists all files", "[fs]")
+{
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
+    REQUIRE(SPIFFS.begin());
+    createFile("/empty", "");
+    createFile("/not_empty", "some text");
+    createFile("/another", "more text");
+    createFile("/subdir/empty", "");
+    createFile("/subdir/not_empty", "text again");
+    auto files = listDir("/");
+    REQUIRE(files.size() == 5);
+    REQUIRE(files.find("/empty") != std::end(files));
+    REQUIRE(files.find("/not_empty") != std::end(files));
+    REQUIRE(files.find("/another") != std::end(files));
+    REQUIRE(files.find("/subdir/empty") != std::end(files));
+    REQUIRE(files.find("/subdir/not_empty") != std::end(files));
+}
+
+TEST_CASE("File names which are too long are rejected", "[fs]")
+{
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
+    REQUIRE(SPIFFS.begin());
+    const char* emptyName = "";
+    const char* longName_31 = "/234567890123456789012345678901";
+    const char* longName_32 = "/2345678901234567890123456789012";
+    REQUIRE_FALSE(SPIFFS.open(emptyName, "w"));
+    REQUIRE_FALSE(SPIFFS.open(emptyName, "r"));
+    REQUIRE_FALSE(SPIFFS.exists(emptyName));
+    REQUIRE_FALSE(SPIFFS.open(longName_32, "w"));
+    REQUIRE_FALSE(SPIFFS.open(longName_32, "r"));
+    REQUIRE_FALSE(SPIFFS.exists(longName_32));
+    REQUIRE(SPIFFS.open(longName_31, "w"));
+    REQUIRE(SPIFFS.open(longName_31, "r"));
+    REQUIRE(SPIFFS.exists(longName_31));
+    auto files = listDir("");
+    REQUIRE(files.empty());
+}
+
+TEST_CASE("#1685 Duplicate files", "[fs][bugreport]") {
+    SPIFFS_MOCK_DECLARE(64, 8, 512);
+    REQUIRE(SPIFFS.begin());
+    createFile("/config", "some text");
+    createFile("/data", "");
+    readFile("/config");
+    createFile("/data", "more text");
+    listDir("/");
+}