filtering output files from luis:cross-train when encounter Composer generated source luis and qna files (#1227)

* filter composer generate source lu and qna file

* fix tslint error

Author: Shuai Wang

packages/luis/src/commands/luis/cross-train.ts

@@ -88,7 +88,10 @@ export default class LuisCrossTrain extends Command {
             validatedPath = utils.validatePath(fileId + fileExt, '', force)
           }
 
-          await fs.writeFile(validatedPath, fileIdToLuResourceMap.get(fileId).Content, 'utf-8')
+          const composerSourceFileRegex = new RegExp(`[\\w-]+\\.source\\.([\\w-]+\\.)?${fileExt.substring(1)}`)
+          if (!composerSourceFileRegex.test(validatedPath)) {
+            await fs.writeFile(validatedPath, fileIdToLuResourceMap.get(fileId).Content, 'utf-8')
+          }
         } catch (err) {
           throw new CLIError(`Unable to write to file ${fileId}. Error: ${err.message}`)
         }

packages/luis/test/commands/luis/crossTrain.test.ts

@@ -173,5 +173,6 @@ describe('luis:cross-train tests for lu and qna contents', () => {
       expect(await compareLuFiles('./../../../interruptionGen/ChitchatDialog.en-us.lu', './../../fixtures/verified/interruption9/ChitchatDialog.en-us.lu')).to.be.true
       expect(await compareLuFiles('./../../../interruptionGen/ChitchatDialog.en-us.qna', './../../fixtures/verified/interruption9/ChitchatDialog.en-us.qna')).to.be.true
       expect(fs.existsSync('./../../../interruptionGen/extra.en-us.lu')).to.be.false
+      expect(fs.existsSync('./../../../interruptionGen/chitchat_professional.source.en-us.qna')).to.be.false
     })
 })