[Artifacts] Exempt certain types of files from gzip compression (#956)

* Exempt certain types of files from gzip compression

* Fix lint issue

packages/artifact/__tests__/upload-gzip.test.ts

@@ -0,0 +1,79 @@
+import * as core from '@actions/core'
+import * as tmp from 'tmp-promise'
+import * as path from 'path'
+import * as io from '../../io/src/io'
+import {promises as fs} from 'fs'
+import {createGZipFileOnDisk} from '../src/internal/upload-gzip'
+
+const root = path.join(__dirname, '_temp', 'upload-gzip')
+const tempGzipFilePath = path.join(root, 'file1.gzip')
+const tempZipFilePath = path.join(root, 'file2.zip')
+const tempTarlzFilePath = path.join(root, 'file3.tar.lz')
+const tempGzFilePath = path.join(root, 'file4.tar.gz')
+const tempBz2FilePath = path.join(root, 'file5.tar.bz2')
+const temp7zFilePath = path.join(root, 'file6.7z')
+const tempNormalFilePath = path.join(root, 'file6.txt')
+
+jest.mock('../src/internal/config-variables')
+
+beforeAll(async () => {
+  // mock all output so that there is less noise when running tests
+  jest.spyOn(console, 'log').mockImplementation(() => {})
+  jest.spyOn(core, 'debug').mockImplementation(() => {})
+  jest.spyOn(core, 'info').mockImplementation(() => {})
+  jest.spyOn(core, 'warning').mockImplementation(() => {})
+  jest.spyOn(core, 'error').mockImplementation(() => {})
+
+  // clear temp directory and create files that will be "uploaded"
+  await io.rmRF(root)
+  await fs.mkdir(path.join(root))
+  await fs.writeFile(tempGzipFilePath, 'a file with a .gzip file extension')
+  await fs.writeFile(tempZipFilePath, 'a file with a .zip file extension')
+  await fs.writeFile(tempTarlzFilePath, 'a file with a tar.lz file extension')
+  await fs.writeFile(tempGzFilePath, 'a file with a gz file file extension')
+  await fs.writeFile(tempBz2FilePath, 'a file with a .bz2 file extension')
+  await fs.writeFile(temp7zFilePath, 'a file with a .7z file extension')
+  await fs.writeFile(tempNormalFilePath, 'a file with a .txt file extension')
+})
+
+test('Number.MAX_SAFE_INTEGER is returned when an existing compressed file is used', async () => {
+  // create temporary file
+  const tempFile = await tmp.file()
+
+  expect(await createGZipFileOnDisk(tempGzipFilePath, tempFile.path)).toEqual(
+    Number.MAX_SAFE_INTEGER
+  )
+  expect(await createGZipFileOnDisk(tempZipFilePath, tempFile.path)).toEqual(
+    Number.MAX_SAFE_INTEGER
+  )
+  expect(await createGZipFileOnDisk(tempTarlzFilePath, tempFile.path)).toEqual(
+    Number.MAX_SAFE_INTEGER
+  )
+  expect(await createGZipFileOnDisk(tempGzFilePath, tempFile.path)).toEqual(
+    Number.MAX_SAFE_INTEGER
+  )
+  expect(await createGZipFileOnDisk(tempBz2FilePath, tempFile.path)).toEqual(
+    Number.MAX_SAFE_INTEGER
+  )
+  expect(await createGZipFileOnDisk(temp7zFilePath, tempFile.path)).toEqual(
+    Number.MAX_SAFE_INTEGER
+  )
+  expect(
+    await createGZipFileOnDisk(tempNormalFilePath, tempFile.path)
+  ).not.toEqual(Number.MAX_SAFE_INTEGER)
+})
+
+test('gzip file on disk gets successfully created', async () => {
+  // create temporary file
+  const tempFile = await tmp.file()
+
+  const gzipFileSize = await createGZipFileOnDisk(
+    tempNormalFilePath,
+    tempFile.path
+  )
+  const fileStat = await fs.stat(tempNormalFilePath)
+  const totalFileSize = fileStat.size
+
+  // original file and gzip file should not be equal in size
+  expect(gzipFileSize).not.toEqual(totalFileSize)
+})

packages/artifact/src/internal/upload-gzip.ts

@@ -3,6 +3,20 @@ import * as zlib from 'zlib'
 import {promisify} from 'util'
 const stat = promisify(fs.stat)
 
+/**
+ * GZipping certain files that are already compressed will likely not yield further size reductions. Creating large temporary gzip
+ * files then will just waste a lot of time before ultimately being discarded (especially for very large files).
+ * If any of these types of files are encountered then on-disk gzip creation will be skipped and the original file will be uploaded as-is
+ */
+const gzipExemptFileExtensions = [
+  '.gzip',
+  '.zip',
+  '.tar.lz',
+  '.tar.gz',
+  '.tar.bz2',
+  '.7z'
+]
+
 /**
  * Creates a Gzip compressed file of an original file at the provided temporary filepath location
  * @param {string} originalFilePath filepath of whatever will be compressed. The original file will be unmodified
@@ -13,6 +27,13 @@ export async function createGZipFileOnDisk(
   originalFilePath: string,
   tempFilePath: string
 ): Promise<number> {
+  for (const gzipExemptExtension of gzipExemptFileExtensions) {
+    if (originalFilePath.endsWith(gzipExemptExtension)) {
+      // return a really large number so that the original file gets uploaded
+      return Number.MAX_SAFE_INTEGER
+    }
+  }
+
   return new Promise((resolve, reject) => {
     const inputStream = fs.createReadStream(originalFilePath)
     const gzip = zlib.createGzip()