diff --git a/filter_test.go b/filter_test.go
new file mode 100644
index 0000000..ffe6c8e
--- /dev/null
+++ b/filter_test.go
@@ -0,0 +1,89 @@
+package gomatrix
+
+import (
+	"encoding/json"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+// sample from docs
+var testFilter = `
+{
+  "room": {
+    "state": {
+      "types": [
+        "m.room.*"
+      ],
+      "not_rooms": [
+        "!726s6s6q:example.com"
+      ]
+    },
+    "timeline": {
+      "limit": 10,
+      "types": [
+        "m.room.message"
+      ],
+      "not_rooms": [
+        "!726s6s6q:example.com"
+      ],
+      "not_senders": [
+        "@spam:example.com"
+      ]
+    },
+    "ephemeral": {
+      "types": [
+        "m.receipt",
+        "m.typing"
+      ],
+      "not_rooms": [
+        "!726s6s6q:example.com"
+      ],
+      "not_senders": [
+        "@spam:example.com"
+      ]
+    }
+  },
+  "presence": {
+    "types": [
+      "m.presence"
+    ],
+    "not_senders": [
+      "@alice:example.com"
+    ]
+  },
+  "event_format": "client",
+  "event_fields": [
+    "type",
+    "content",
+    "sender"
+  ]
+}`
+
+func TestFilterValidate(t *testing.T) {
+	var f Filter
+	err := json.NewDecoder(strings.NewReader(testFilter)).Decode(&f)
+	if err != nil {
+		t.Fatalf("TestFilterValidate: Failed to parse %s", testFilter)
+	}
+	// test validadtion success
+	if err = f.Validate(); err != nil {
+		t.Fatalf("TestFilterValidate: Filter validation has failed, event_format: '%s'", f.EventFormat)
+	}
+	// test validation fail
+	f.EventFormat = "unkown"
+	err = f.Validate()
+	if err == nil || err.Error() != "Bad event_format value. Must be one of [\"client\", \"federation\"]" {
+		t.Fatalf("TestFilterValidate: Filter validation false positive, event_format: '%s'", f.EventFormat)
+	}
+}
+
+func TestDefaultFilter(t *testing.T) {
+	defaultFilter := DefaultFilter()
+	if reflect.TypeOf(defaultFilter) != reflect.TypeOf(Filter{}) {
+		t.Fatal("TestDefaultFilter: Invalid type for default filter")
+	}
+	if defaultFilter.EventFormat != "client" {
+		t.Fatalf("TestDefaultFilter: expected EventFormat %s,  got %s", "client", defaultFilter.EventFormat)
+	}
+}