diff --git a/formatter/formatter_test.go b/formatter/formatter_test.go
index c8db643..de56f8e 100644
--- a/formatter/formatter_test.go
+++ b/formatter/formatter_test.go
@@ -15,13 +15,13 @@ import (
 const loremIpsum = `Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.`
 
 func TestFormatJIRAEventToSlackMessage(t *testing.T) {
-	fixtures := []struct {
+	matrix := []struct {
 		source   string
-		expected message.Message
+		expected *message.Message
 	}{
 		{
 			source: "../testdata/issue_created.json",
-			expected: message.Message{
+			expected: &message.Message{
 				Text: "<@alice> created the issue: ",
 				Attachments: message.Attachments{{
 					Title:     "TEST-4: Lorem Ipsum",
@@ -31,30 +31,99 @@ func TestFormatJIRAEventToSlackMessage(t *testing.T) {
 				}},
 			},
 		},
+		{
+			source: "../testdata/issue_deleted.json",
+			expected: &message.Message{
+				Text: "<@alice> deleted the issue (assigned to <@alice>): ",
+				Attachments: message.Attachments{{
+					Title:     "TEST-4: Lorem Ipsum",
+					TitleLink: "https://jira.example.com/browse/TEST-4",
+					Timestamp: 1519993669,
+				}},
+			},
+		},
+		{
+			source: "../testdata/issue_updated_assigned.json",
+			expected: &message.Message{
+				Text: "<@alice> assigned the issue (assigned to <@alice>): ",
+				Attachments: message.Attachments{{
+					Title:     "TEST-4: Lorem Ipsum",
+					TitleLink: "https://jira.example.com/browse/TEST-4",
+					Text:      loremIpsum,
+					Timestamp: 1519993563,
+				}},
+			},
+		},
+		{
+			source:   "../testdata/issue_updated_comment_deleted.json",
+			expected: nil,
+		},
+		{
+			source: "../testdata/issue_updated_commented.json",
+			expected: &message.Message{
+				Text: "<@alice> commented the issue: <@bob>",
+				Attachments: message.Attachments{{
+					Title:     "TEST-4: Lorem Ipsum",
+					TitleLink: "https://jira.example.com/browse/TEST-4",
+					Text:      loremIpsum,
+					Timestamp: 1519993498,
+				}},
+			},
+		},
+		{
+			source: "../testdata/issue_updated_summary.json",
+			expected: &message.Message{
+				Text: "<@alice> updated the issue: ",
+				Attachments: message.Attachments{{
+					Title:     "TEST-2: Lorem Ipsum",
+					TitleLink: "https://jira.example.com/browse/TEST-2",
+					Timestamp: 1520002692,
+				}},
+			},
+		},
+		{
+			source:   "../testdata/issue_updated_transition.json",
+			expected: nil,
+		},
+		{
+			source:   "../testdata/comment_created.json",
+			expected: nil,
+		},
+		{
+			source:   "../testdata/comment_deleted.json",
+			expected: nil,
+		},
 	}
 	formatter := &Formatter{&message.SlackDialect{}}
-	for i := 0; i < len(fixtures); i++ {
-		fixture := fixtures[i]
-
-		f, err := os.Open(fixture.source)
-		if err != nil {
-			t.Fatal(err)
-		}
-		defer f.Close()
-
-		r := bufio.NewReader(f)
-		var event jira.Event
-		if err := json.NewDecoder(r).Decode(&event); err != nil {
-			t.Fatal(err)
-		}
-
-		expected := fixture.expected
-		actual := formatter.JIRAEventToSlackMessage(&event)
-		if actual.Text != expected.Text {
-			t.Errorf("Text = %s, want %s", actual.Text, expected.Text)
-		}
-		if !reflect.DeepEqual(actual.Attachments, expected.Attachments) {
-			t.Errorf("Attachments\n actual = %+v,\n expected = %+v", actual.Attachments, expected.Attachments)
-		}
+	for i := 0; i < len(matrix); i++ {
+		m := matrix[i]
+		t.Run(m.source, func(t *testing.T) {
+			f, err := os.Open(m.source)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer f.Close()
+
+			r := bufio.NewReader(f)
+			var event jira.Event
+			if err := json.NewDecoder(r).Decode(&event); err != nil {
+				t.Fatal(err)
+			}
+
+			actual := formatter.JIRAEventToSlackMessage(&event)
+
+			switch {
+			case m.expected == nil && actual == nil:
+				// OK
+			case m.expected == nil && actual != nil:
+				t.Errorf("message wants nil but %+v", actual)
+			case m.expected != nil && actual == nil:
+				t.Errorf("message wants non-nil but nil")
+			case m.expected.Text != actual.Text:
+				t.Errorf("message.Text wants %s but %s", m.expected.Text, actual.Text)
+			case !reflect.DeepEqual(m.expected.Attachments, actual.Attachments):
+				t.Errorf("message.Attachments wants %+v but %+v", m.expected.Attachments, actual.Attachments)
+			}
+		})
 	}
 }