SpreadsheetApp.create expects a string and it is used to create new spreadsheet with the passed string. Refer the below code to unzip and upload the file in the Google drive.
Edit 1: The below function will upload the unzipped file in its native format.
function unZipIt() {
var theFolder = DriveApp.getFolderById('0B9jgHw-WmzvfRS1ZZEhTc3Byak0');
var theFile = theFolder.getFilesByName('Dock to Stock Weekly_Dock to Stock AMP.zip');
var fileBlob = theFile.next().getBlob();
fileBlob.setContentType("application/zip");
var unZippedfile = Utilities.unzip(fileBlob);
var newDriveFile = DriveApp.createFile(unZippedfile[0]);
Logger.log(newDriveFile.getId())
}
Edit 2: The below functions will upload the unzipped file and will convert it into Google drive format
function unZipIt() {
var theFolder = DriveApp.getFolderById('0B5JsAY8jN1CoWnhxU0Izemp6WW8');
var theFile = theFolder.getFilesByName('test.zip');
var fileBlob = theFile.next().getBlob();
fileBlob.setContentType("application/zip");
var unZippedfile = Utilities.unzip(fileBlob);
var newDriveFile = DriveApp.createFile(unZippedfile[0]);
convertToGoogleDocs(newDriveFile.getId())
}
function convertToGoogleDocs(fileId) {
try{
var originalFile = DriveApp.getFileById(fileId);
var uploadFile = JSON.parse(UrlFetchApp.fetch(
"https://www.googleapis.com/upload/drive/v2/files?uploadType=media&convert=true",
{
method: "POST",
contentType: originalFile.getMimeType(),
payload: originalFile.getBlob().getBytes(),
headers: {
"Authorization" : "Bearer " + ScriptApp.getOAuthToken()
},
muteHttpExceptions: true
}
).getContentText());
// Remove the file extension from the new google file name
var googleFileName = originalFile.setName(originalFile.getName().substr(0, originalFile.getName().lastIndexOf(".")));
// Update the name of the Google file created from the original file
DriveApp.getFileById(uploadFile.id).setName(googleFileName);
var files = DriveApp.getFileById(uploadFile.id);
}
catch(e){
Logger.log(e)
}
}