Apply strictNullChecks to src/utils/exportUtils (#10379)

* Apply `strictNullChecks` to `src/utils/exportUtils`

* strict fix

* test coverage

* lint

* test coverage

* one more test

test/utils/exportUtils/HTMLExport-test.ts

@@ -14,7 +14,16 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { EventType, IRoomEvent, MatrixClient, MatrixEvent, MsgType, Room, RoomMember } from "matrix-js-sdk/src/matrix";
+import {
+    EventType,
+    IRoomEvent,
+    MatrixClient,
+    MatrixEvent,
+    MsgType,
+    Room,
+    RoomMember,
+    RoomState,
+} from "matrix-js-sdk/src/matrix";
 import fetchMock from "fetch-mock-jest";
 
 import { filterConsole, mkStubRoom, REPEATABLE_DATE, stubClient } from "../../test-utils";
@@ -51,6 +60,20 @@ const EVENT_ATTACHMENT: IRoomEvent = {
     },
 };
 
+const EVENT_ATTACHMENT_MALFORMED: IRoomEvent = {
+    event_id: "$2",
+    type: EventType.RoomMessage,
+    sender: "@alice:example.com",
+    origin_server_ts: 1,
+    content: {
+        msgtype: MsgType.File,
+        body: "hello.txt",
+        file: {
+            url: undefined,
+        },
+    },
+};
+
 describe("HTMLExport", () => {
     let client: jest.Mocked<MatrixClient>;
     let room: Room;
@@ -107,6 +130,22 @@ describe("HTMLExport", () => {
         fetchMock.get(media.srcHttp!, body);
     }
 
+    it("should throw when created with invalid config for LastNMessages", async () => {
+        expect(
+            () =>
+                new HTMLExporter(
+                    room,
+                    ExportType.LastNMessages,
+                    {
+                        attachmentsIncluded: false,
+                        maxSize: 1_024 * 1_024,
+                        numberOfMessages: undefined,
+                    },
+                    () => {},
+                ),
+        ).toThrow("Invalid export options");
+    });
+
     it("should have an SDK-branded destination file name", () => {
         const roomName = "My / Test / Room: Welcome";
         const stubOptions: IExportOptions = {
@@ -266,6 +305,56 @@ describe("HTMLExport", () => {
         expect(await file.text()).toBe(avatarContent);
     });
 
+    it("should handle when an event has no sender", async () => {
+        const EVENT_MESSAGE_NO_SENDER: IRoomEvent = {
+            event_id: "$1",
+            type: EventType.RoomMessage,
+            sender: "",
+            origin_server_ts: 0,
+            content: {
+                msgtype: "m.text",
+                body: "Message with no sender",
+            },
+        };
+        mockMessages(EVENT_MESSAGE_NO_SENDER);
+
+        const exporter = new HTMLExporter(
+            room,
+            ExportType.Timeline,
+            {
+                attachmentsIncluded: false,
+                maxSize: 1_024 * 1_024,
+            },
+            () => {},
+        );
+
+        await exporter.export();
+
+        const file = getMessageFile(exporter);
+        expect(await file.text()).toContain(EVENT_MESSAGE_NO_SENDER.content.body);
+    });
+
+    it("should handle when events sender cannot be found in room state", async () => {
+        mockMessages(EVENT_MESSAGE);
+
+        jest.spyOn(RoomState.prototype, "getSentinelMember").mockReturnValue(null);
+
+        const exporter = new HTMLExporter(
+            room,
+            ExportType.Timeline,
+            {
+                attachmentsIncluded: false,
+                maxSize: 1_024 * 1_024,
+            },
+            () => {},
+        );
+
+        await exporter.export();
+
+        const file = getMessageFile(exporter);
+        expect(await file.text()).toContain(EVENT_MESSAGE.content.body);
+    });
+
     it("should include attachments", async () => {
         mockMessages(EVENT_MESSAGE, EVENT_ATTACHMENT);
         const attachmentBody = "Lorem ipsum dolor sit amet";
@@ -294,6 +383,68 @@ describe("HTMLExport", () => {
         expect(text).toBe(attachmentBody);
     });
 
+    it("should handle when attachment cannot be fetched", async () => {
+        mockMessages(EVENT_MESSAGE, EVENT_ATTACHMENT_MALFORMED, EVENT_ATTACHMENT);
+        const attachmentBody = "Lorem ipsum dolor sit amet";
+
+        mockMxc("mxc://example.org/test-id", attachmentBody);
+
+        const exporter = new HTMLExporter(
+            room,
+            ExportType.Timeline,
+            {
+                attachmentsIncluded: true,
+                maxSize: 1_024 * 1_024,
+            },
+            () => {},
+        );
+
+        await exporter.export();
+
+        // good attachment present
+        const files = getFiles(exporter);
+        const file = files[Object.keys(files).find((k) => k.endsWith(".txt"))!];
+        expect(file).not.toBeUndefined();
+
+        // Ensure that the attachment has the expected content
+        const text = await file.text();
+        expect(text).toBe(attachmentBody);
+
+        // messages export still successful
+        const messagesFile = getMessageFile(exporter);
+        expect(await messagesFile.text()).toBeTruthy();
+    });
+
+    it("should handle when attachment srcHttp is falsy", async () => {
+        mockMessages(EVENT_MESSAGE, EVENT_ATTACHMENT);
+        const attachmentBody = "Lorem ipsum dolor sit amet";
+
+        mockMxc("mxc://example.org/test-id", attachmentBody);
+
+        jest.spyOn(client, "mxcUrlToHttp").mockReturnValue(null);
+
+        const exporter = new HTMLExporter(
+            room,
+            ExportType.Timeline,
+            {
+                attachmentsIncluded: true,
+                maxSize: 1_024 * 1_024,
+            },
+            () => {},
+        );
+
+        await exporter.export();
+
+        // attachment not present
+        const files = getFiles(exporter);
+        const file = files[Object.keys(files).find((k) => k.endsWith(".txt"))!];
+        expect(file).toBeUndefined();
+
+        // messages export still successful
+        const messagesFile = getMessageFile(exporter);
+        expect(await messagesFile.text()).toBeTruthy();
+    });
+
     it("should omit attachments", async () => {
         mockMessages(EVENT_MESSAGE, EVENT_ATTACHMENT);
 
@@ -323,6 +474,7 @@ describe("HTMLExport", () => {
             {
                 attachmentsIncluded: false,
                 maxSize: 1_024 * 1_024,
+                numberOfMessages: 5000,
             },
             () => {},
         );