Add channels param to files.upload v2 method (and its underlying files.completeUploadExternal)

slack-api-client/src/main/java/com/slack/api/methods/RequestFormBuilder.java

@@ -2086,7 +2086,11 @@
         if (req.getFiles() != null) {
             setIfNotNull("files", GSON.toJson(req.getFiles()), form);
         }
-        setIfNotNull("channel_id", req.getChannelId(), form);
+        if (req.getChannels() != null) {
+            setIfNotNull("channels", req.getChannels().stream().collect(joining(",")), form);
+        } else {
+            setIfNotNull("channel_id", req.getChannelId(), form);
+        }
         setIfNotNull("initial_comment", req.getInitialComment(), form);
         setIfNotNull("thread_ts", req.getThreadTs(), form);
         return form;

slack-api-client/src/main/java/com/slack/api/methods/impl/FilesUploadV2Helper.java

@@ -94,6 +94,7 @@
                 .token(v2Request.getToken())
                 .files(files)
                 .channelId(v2Request.getChannel())
+                .channels(v2Request.getChannels())
                 .initialComment(v2Request.getInitialComment())
                 .threadTs(v2Request.getThreadTs())
         );

slack-api-client/src/main/java/com/slack/api/methods/request/files/FilesCompleteUploadExternalRequest.java

@@ -30,6 +30,11 @@ public class FilesCompleteUploadExternalRequest implements SlackApiRequest {
      */
     private String channelId;
 
+    /**
+     * Comma-separated string of channel IDs where the file will be shared.
+     */
+    private List<String> channels;
+
     /**
      * The message text introducing the file in specified channels.
      */

slack-api-client/src/main/java/com/slack/api/methods/request/files/FilesUploadV2Request.java

@@ -130,6 +130,11 @@ public static class UploadFile {
      */
     private String channel;
 
+    /**
+     * Comma-separated string of channel IDs where the file will be shared.
+     */
+    private List<String> channels;
+
     /**
      * Provide another message's ts value to upload this file as a reply.
      * Never use a reply's ts value; use its parent instead.

slack-api-client/src/test/java/test_with_remote_apis/methods/files_Test.java

@@ -46,6 +46,7 @@
 @Slf4j
 public class files_Test {
 
+    private String generalChannelId = null;
     private String randomChannelId = null;
 
     void loadRandomChannelId() throws IOException, SlackApiException {
@@ -62,6 +63,20 @@ void loadRandomChannelId() throws IOException, SlackApiException {
         }
     }
 
+    void loadGeneralChannelId() throws IOException, SlackApiException {
+        if (generalChannelId == null) {
+            ConversationsListResponse channelsListResponse =
+                    slack.methods().conversationsList(r -> r.token(botToken).excludeArchived(true).limit(100));
+            assertThat(channelsListResponse.getError(), is(nullValue()));
+            for (Conversation channel : channelsListResponse.getChannels()) {
+                if (channel.getName().equals("general")) {
+                    generalChannelId = channel.getId();
+                    break;
+                }
+            }
+        }
+    }
+
     static SlackTestConfig testConfig = SlackTestConfig.getInstance();
     static Slack slack = Slack.getInstance(testConfig.getConfig());
 
@@ -1254,4 +1269,52 @@ public void issue1345_filesUploadV2_multiple_no_filename_no_title() throws IOExc
         // title defaults to filename, which is (as this is defaulted on the client side) "Uploaded file"
         assertThat(response.getFiles().get(0).getTitle(), is("Uploaded file"));
     }
+
+    @Test
+    public void filesUploadV2_channels() throws Exception {
+        loadRandomChannelId();
+        loadGeneralChannelId();
+        MethodsClient client = slack.methods(botToken);
+
+        File file1 = new File("src/test/resources/sample.txt");
+        FilesUploadV2Response response = client.filesUploadV2(r -> r
+                .file(file1)
+                .title("sample.txt")
+                .filename("sample.txt")
+                .snippetType("text")
+                .channels(Arrays.asList(generalChannelId, randomChannelId))
+                .initialComment("Here you are :wave:")
+        );
+        assertThat(response.getError(), is(nullValue()));
+
+        List<String> expectedFileIds = response.getFiles().stream()
+                .map(a -> a.getId()).collect(Collectors.toList());
+
+        int count = 0;
+        ConversationsHistoryResponse history = null;
+        List<String> actualFileIds = null;
+        while (count < 10) {
+            count++;
+            history = client.conversationsHistory(r -> r
+                    .channel(randomChannelId)
+                    .limit(1)
+            );
+            if (history.getMessages().get(0).getFiles() != null) {
+                actualFileIds = history.getMessages().get(0).getFiles().stream()
+                        .map(a -> a.getId()).sorted().collect(Collectors.toList());
+                if (actualFileIds.stream().collect(Collectors.joining(","))
+                        .equals(expectedFileIds.stream().collect(Collectors.joining(",")))) {
+                    break;
+                }
+            }
+            Thread.sleep(3000L);
+        }
+        assertThat(history.getError(), is(nullValue()));
+        assertThat(history.getMessages().get(0).getFiles(), is(notNullValue()));
+        assertThat(actualFileIds, is(expectedFileIds));
+
+        FilesInfoResponse file1info = client.filesInfo(r -> r.file(response.getFile().getId()));
+        assertThat(file1info.getFile().getShares().getPublicChannels().get(randomChannelId), is(notNullValue()));
+    }
+
 }