qemu-iotests: Merge FilePaths and FilePath

FilePath creates now one temporary file:

    with FilePath("a") as a:

Or more:

    with FilePath("a", "b", "c") as (a, b, c):

This is also the behavior of the file_path() helper, used by some of the
tests. Now we have only 2 helpers for creating temporary files instead
of 3.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200828232152.205833-5-nsoffer@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

tests/qemu-iotests/194

@@ -26,7 +26,7 @@ iotests.script_initialize(supported_fmts=['qcow2', 'qed', 'raw'],
 
 with iotests.FilePath('source.img') as source_img_path, \
      iotests.FilePath('dest.img') as dest_img_path, \
-     iotests.FilePaths('migration.sock', 'nbd.sock', base_dir=iotests.sock_dir) \
+     iotests.FilePath('migration.sock', 'nbd.sock', base_dir=iotests.sock_dir) \
         as (migration_sock_path, nbd_sock_path), \
      iotests.VM('source') as source_vm, \
      iotests.VM('dest') as dest_vm:

tests/qemu-iotests/208

@@ -26,7 +26,7 @@ iotests.script_initialize(supported_fmts=['generic'])
 
 with iotests.FilePath('disk.img') as disk_img_path, \
      iotests.FilePath('disk-snapshot.img') as disk_snapshot_img_path, \
-     iotests.FilePath('nbd.sock', iotests.sock_dir) as nbd_sock_path, \
+     iotests.FilePath('nbd.sock', base_dir=iotests.sock_dir) as nbd_sock_path, \
      iotests.VM() as vm:
 
     img_size = '10M'

tests/qemu-iotests/222

@@ -49,7 +49,7 @@ remainder = [("0xd5", "0x108000",  "32k"), # Right-end of partial-left [1]
 
 with iotests.FilePath('base.img') as base_img_path, \
      iotests.FilePath('fleece.img') as fleece_img_path, \
-     iotests.FilePath('nbd.sock', iotests.sock_dir) as nbd_sock_path, \
+     iotests.FilePath('nbd.sock', base_dir=iotests.sock_dir) as nbd_sock_path, \
      iotests.VM() as vm:
 
     log('--- Setting up images ---')

tests/qemu-iotests/257

@@ -275,7 +275,7 @@ def test_bitmap_sync(bsync_mode, msync_mode='bitmap', failure=None):
                         an incomplete backup. Testing limitations prevent
                         testing competing writes.
     """
-    with iotests.FilePaths(
+    with iotests.FilePath(
             'img', 'bsync1', 'bsync2', 'fbackup0', 'fbackup1', 'fbackup2') as \
             (img_path, bsync1, bsync2, fbackup0, fbackup1, fbackup2), \
          iotests.VM() as vm:
@@ -440,7 +440,7 @@ def test_backup_api():
     """
     Test malformed and prohibited invocations of the backup API.
     """
-    with iotests.FilePaths('img', 'bsync1') as (img_path, backup_path), \
+    with iotests.FilePath('img', 'bsync1') as (img_path, backup_path), \
          iotests.VM() as vm:
 
         log("\n=== API failure tests ===\n")

tests/qemu-iotests/iotests.py

@@ -448,14 +448,14 @@ class Timeout:
 def file_pattern(name):
     return "{0}-{1}".format(os.getpid(), name)
 
-class FilePaths:
+class FilePath:
     """
     Context manager generating multiple file names. The generated files are
     removed when exiting the context.
 
     Example usage:
 
-        with FilePaths('a.img', 'b.img') as (img_a, img_b):
+        with FilePath('a.img', 'b.img') as (img_a, img_b):
             # Use img_a and img_b here...
 
         # a.img and b.img are automatically removed here.
@@ -463,7 +463,10 @@ class FilePaths:
     By default images are created in iotests.test_dir. To create sockets use
     iotests.sock_dir:
 
-       with FilePaths('a.sock', base_dir=iotests.sock_dir) as (sock,):
+       with FilePath('a.sock', base_dir=iotests.sock_dir) as sock:
+
+    For convenience, calling with one argument yields a single file instead of
+    a tuple with one item.
 
     """
     def __init__(self, *names, base_dir=test_dir):
@@ -472,7 +475,10 @@ class FilePaths:
             self.paths.append(os.path.join(base_dir, file_pattern(name)))
 
     def __enter__(self):
-        return self.paths
+        if len(self.paths) == 1:
+            return self.paths[0]
+        else:
+            return self.paths
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         for path in self.paths:
@@ -482,15 +488,6 @@ class FilePaths:
                 pass
         return False
 
-class FilePath(FilePaths):
-    """
-    FilePath is a specialization of FilePaths that takes a single filename.
-    """
-    def __init__(self, name, base_dir=test_dir):
-        super(FilePath, self).__init__(name, base_dir=base_dir)
-
-    def __enter__(self):
-        return self.paths[0]
 
 def file_path_remover():
     for path in reversed(file_path_remover.paths):