Check in extractFiles handles all cases

file.go

@@ -81,14 +81,42 @@ func extractFiles(zipFilePath, filesToExtractFromZipPath, localPath string) erro
 
 	// Add the path from which we will extract files to the path prefix so we can exclude the appropriate files
 	pathPrefix = filepath.Join(pathPrefix, filesToExtractFromZipPath)
-	pathPrefix = pathPrefix + "/"
 
 	// Iterate through the files in the archive,
 	// printing some of their contents.
 	for _, f := range r.File {
 
-		// If the given file is in the filesToExtractFromZipPath, proceed
-		if strings.Index(f.Name, pathPrefix) == 0 {
+			//
+			// Skip the current archive item being processed based on
+			// rules described in comments below.
+			//
+			if f.FileInfo().IsDir() {
+				// The current archive item is a directory.
+				// Archive item's f.Name will always be appended with a "/", so we use
+				// that fact to ensure we are working with a full directory name. Skip
+				// to next item if (pathPrefix + "/") is not a prefix in f.Name
+				if strings.Index(f.Name, pathPrefix + "/") != 0 {
+					continue
+				}
+			} else {
+				// The current archive item is a file.
+				// There are three things possible here:
+				//		1  User specified a filename using --source-path option and if we hit
+				//		   that file in archive, we need to process this file, so do not skip.
+				//      2  We do additional checks if we did not hit the exact file specified by user:
+				//			2a User specified a directory (or wants to download full repo);
+				//		   	   the (pathPrefix + "/") is a prefix in f.Name, we want to process this
+				//		   	   file, so not skipping.
+				//			2b User specified either file or directory.
+				//             (pathPrefix + "/") is not a prefix in the current item's f.Name, we
+				//             have hit a file that is not within the folder that the user specified,
+				// 			   so we skip it.
+				if f.Name != pathPrefix {
+					if strings.Index(f.Name, pathPrefix + "/") != 0 {
+						continue
+					}
+				}
+			}
 
 			if f.FileInfo().IsDir() {
 				// Create a directory
@@ -115,7 +143,6 @@ func extractFiles(zipFilePath, filesToExtractFromZipPath, localPath string) erro
 					return fmt.Errorf("Failed to write file: %s", err)
 				}
 			}
-		}
 	}
 
 	return nil

file_test.go

@@ -340,6 +340,35 @@ func TestExtractFiles(t *testing.T) {
 	}
 }
 
+func TestExtractFilesExtractFile(t *testing.T) {
+	// Create a temp directory
+	tempDir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatalf("Failed to create temp directory: %s", err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	zipFilePath := "test-fixtures/fetch-test-public-0.0.4.zip"
+	filePathToExtract := "zzz.txt"
+	localFileName := "/localzzz.txt"
+	localPathName := filepath.Join(tempDir, localFileName)
+	err = extractFiles(zipFilePath, filePathToExtract, localPathName)
+	if err != nil {
+		t.Fatalf("Failed to extract files: %s", err)
+	}
+
+	filepath.Walk(tempDir, func(path string, info os.FileInfo, err error) error {
+		relativeFilename := strings.TrimPrefix(path, tempDir)
+
+		if ! info.IsDir() {
+			if relativeFilename != localFileName {
+				t.Fatalf("Expected local file %s to be created, but not found.\n", localFileName)
+			}
+		}
+		return nil
+	})
+}
+
 // Return ture if the given slice contains the given string
 func stringInSlice(s string, slice []string) bool {
 	for _, val := range slice {