Refactor archive type checks to be more DRY

This should be an in-place refactor without any additional behaviors or
side effects.

Fixes #6147

src/cli/plugin/__tests__/type_from_filename.js

@@ -0,0 +1,27 @@
+import expect from 'expect.js';
+import typeFromFilename, { ZIP, TAR } from '../type_from_filename';
+
+describe('kibana cli', function () {
+  describe('type_from_filename', function () {
+    it('returns ZIP for .zip filename', function () {
+      const type = typeFromFilename('wat.zip');
+      expect(type).to.equal(ZIP);
+    });
+    it('returns TAR for .tar.gz filename', function () {
+      const type = typeFromFilename('wat.tar.gz');
+      expect(type).to.equal(TAR);
+    });
+    it('returns undefined for unknown file type', function () {
+      const type = typeFromFilename('wat.unknown');
+      expect(type).to.equal(undefined);
+    });
+    it('accepts paths', function () {
+      const type = typeFromFilename('/some/path/to/wat.zip');
+      expect(type).to.equal(ZIP);
+    });
+    it('accepts urls', function () {
+      const type = typeFromFilename('http://example.com/wat.zip');
+      expect(type).to.equal(ZIP);
+    });
+  });
+});

src/cli/plugin/downloaders/file.js

@@ -1,5 +1,6 @@
 const { createWriteStream, createReadStream, unlinkSync, statSync } = require('fs');
 const getProgressReporter = require('../progress_reporter');
+import typeFromFilename from '../type_from_filename';
 
 function openSourceFile({ sourcePath }) {
   try {
@@ -36,15 +37,6 @@ async function copyFile({ readStream, writeStream, progressReporter }) {
   });
 }
 
-function getArchiveTypeFromFilename(path) {
-  if (/\.zip$/i.test(path)) {
-    return '.zip';
-  }
-  if (/\.tar\.gz$/i.test(path)) {
-    return '.tar.gz';
-  }
-}
-
 /*
 // Responsible for managing local file transfers
 */
@@ -67,7 +59,7 @@ export default async function copyLocalFile(logger, sourcePath, targetPath) {
     }
 
     // all is well, return our archive type
-    const archiveType = getArchiveTypeFromFilename(sourcePath);
+    const archiveType = typeFromFilename(sourcePath);
     return { archiveType };
   } catch (err) {
     logger.error(err);

src/cli/plugin/downloaders/http.js

@@ -2,6 +2,7 @@ const { fromNode: fn } = require('bluebird');
 const { createWriteStream, unlinkSync } = require('fs');
 const Wreck = require('wreck');
 const getProgressReporter = require('../progress_reporter');
+import typeFromFilename, { ZIP, TAR } from '../type_from_filename';
 
 function sendRequest({ sourceUrl, timeout }) {
   const maxRedirects = 11; //Because this one goes to 11.
@@ -49,18 +50,12 @@ function getArchiveTypeFromResponse(resp, sourceUrl) {
   const contentType = (resp.headers['content-type'] || '');
 
   switch (contentType.toLowerCase()) {
-    case 'application/zip': return '.zip';
-    case 'application/x-gzip': return '.tar.gz';
+    case 'application/zip': return ZIP;
+    case 'application/x-gzip': return TAR;
     default:
       //If we can't infer the archive type from the content-type header,
       //fall back to checking the extension in the url
-      if (/\.zip$/i.test(sourceUrl)) {
-        return '.zip';
-      }
-      if (/\.tar\.gz$/i.test(sourceUrl)) {
-        return '.tar.gz';
-      }
-      break;
+      return typeFromFilename(sourceUrl);
   }
 }
 

src/cli/plugin/plugin_extractor.js

@@ -1,12 +1,13 @@
 const zipExtract = require('./extractors/zip');
 const tarGzExtract = require('./extractors/tar_gz');
+import { ZIP, TAR } from './type_from_filename';
 
 export default function extractArchive(settings, logger, archiveType) {
   switch (archiveType) {
-    case '.zip':
+    case ZIP:
       return zipExtract(settings, logger);
       break;
-    case '.tar.gz':
+    case TAR:
       return tarGzExtract(settings, logger);
       break;
     default:

src/cli/plugin/type_from_filename.js

@@ -0,0 +1,11 @@
+export const TAR = '.tar.gz';
+export const ZIP = '.zip';
+
+export default function typeFromFilename(filename) {
+  if (/\.zip$/i.test(filename)) {
+    return ZIP;
+  }
+  if (/\.tar\.gz$/i.test(filename)) {
+    return TAR;
+  }
+}