fix(ftp/ds): ECONNRESET FTPS error for empty dataset contents

packages/zowe-explorer-ftp-extension/CHANGELOG.md

@@ -6,6 +6,8 @@ All notable changes to the "zowe-explorer-ftp-extension" extension will be docum
 
 ### Bug fixes
 
+- Fixed ECONNRESET error when trying to upload or create an empty data set member. [#2350](https://github.com/zowe/vscode-extension-for-zowe/issues/2350)
+
 ## `2.11.0`
 
 ### Bug fixes

packages/zowe-explorer-ftp-extension/__tests__/__unit__/Mvs/ZoweExplorerFtpMvsApi.unit.test.ts

@@ -123,6 +123,35 @@ describe("FtpMvsApi", () => {
         expect(MvsApi.releaseConnection).toBeCalled();
     });
 
+    it("should upload empty contents to dataset.", async () => {
+        const localFile = tmp.tmpNameSync({ tmpdir: "/tmp" });
+
+        fs.writeFileSync(localFile, "");
+        const response = TestUtils.getSingleLineStream();
+        DataSetUtils.listDataSets = jest.fn().mockReturnValue([{ dsname: "USER.EMPTYDS", dsorg: "PS", lrecl: 2 }]);
+        const uploadDataSetMock = jest.fn().mockReturnValue(response);
+        DataSetUtils.uploadDataSet = uploadDataSetMock;
+        jest.spyOn(MvsApi, "getContents").mockResolvedValue({ apiResponse: { etag: "123" } } as any);
+
+        const mockParams = {
+            inputFilePath: localFile,
+            dataSetName: "USER.EMPTYDS",
+            options: { encoding: "", returnEtag: true, etag: "utf8" },
+        };
+
+        jest.spyOn(MvsApi as any, "getContentsTag").mockReturnValue(undefined);
+        jest.spyOn(fs, "readFileSync").mockReturnValue("");
+        await MvsApi.putContents(mockParams.inputFilePath, mockParams.dataSetName, mockParams.options);
+        expect(DataSetUtils.uploadDataSet).toHaveBeenCalledWith({ host: "", password: "", port: "", user: "" }, "USER.EMPTYDS", {
+            content: " ",
+            encoding: "",
+            transferType: "ascii",
+        });
+        // ensure options object at runtime does not have localFile
+        expect(Object.keys(uploadDataSetMock.mock.calls[0][2]).find((k) => k === "localFile")).toBe(undefined);
+        expect(MvsApi.releaseConnection).toBeCalled();
+    });
+
     it("should create dataset.", async () => {
         DataSetUtils.allocateDataSet = jest.fn();
         const DATA_SET_SEQUENTIAL = 4;

packages/zowe-explorer-ftp-extension/src/ZoweExplorerFtpMvsApi.ts

@@ -112,11 +112,6 @@ export class FtpMvsApi extends AbstractFtpApi implements ZoweExplorerApi.IMvs {
     }
 
     public async putContents(inputFilePath: string, dataSetName: string, options: IUploadOptions): Promise<zowe.IZosFilesResponse> {
-        const transferOptions = {
-            transferType: options.binary ? TRANSFER_TYPE_BINARY : TRANSFER_TYPE_ASCII,
-            localFile: inputFilePath,
-            encoding: options.encoding,
-        };
         const file = path.basename(inputFilePath).replace(/[^a-z0-9]+/gi, "");
         const member = file.substr(0, MAX_MEMBER_NAME_LEN);
         let targetDataset: string;
@@ -153,6 +148,16 @@ export class FtpMvsApi extends AbstractFtpApi implements ZoweExplorerApi.IMvs {
             }
             const lrecl: number = dsAtrribute.apiResponse.items[0].lrecl;
             const data = fs.readFileSync(inputFilePath, { encoding: "utf8" });
+            const transferOptions = {
+                transferType: options.binary ? TRANSFER_TYPE_BINARY : TRANSFER_TYPE_ASCII,
+                localFile: inputFilePath,
+                encoding: options.encoding,
+            };
+            if (data == "") {
+                // substitute single space for empty DS contents when saving (prevents FTP error)
+                transferOptions["content"] = " ";
+                delete transferOptions["localFile"];
+            }
             const lines = data.split(/\r?\n/);
             const foundIndex = lines.findIndex((line) => line.length > lrecl);
             if (foundIndex !== -1) {
@@ -243,8 +248,9 @@ export class FtpMvsApi extends AbstractFtpApi implements ZoweExplorerApi.IMvs {
 
     public async createDataSetMember(dataSetName: string, options?: IUploadOptions): Promise<zowe.IZosFilesResponse> {
         const transferOptions = {
-            transferType: options ? TRANSFER_TYPE_BINARY : TRANSFER_TYPE_ASCII,
-            content: "",
+            transferType: options.binary ? TRANSFER_TYPE_BINARY : TRANSFER_TYPE_ASCII,
+            // we have to provide a single space for content, or zos-node-accessor will fail to upload the data set over FTP
+            content: " ",
             encoding: options.encoding,
         };
         const result = this.getDefaultResponse();