frame-cache writer: simple fixes and testing

hexrd/imageseries/save.py

@@ -190,13 +190,14 @@ def __init__(self, ims, fname, **kwargs):
            the imageseries to write
         fname: str or Path
            name of file to write;
+        threshold: float
+           threshold value for image, at or below which values are zeroed
         cache_file: str or Path, optional
            name of the npz file to save the image data, if not given in the
            `fname` argument; for YAML format (deprecated), this is required
         """
         Writer.__init__(self, ims, fname, **kwargs)
         self._thresh = self._opts['threshold']
-        cf = kwargs['cache_file']
         self._cache, self.cachename = self._set_cache()
         self.max_workers = kwargs.get('max_workers', None)
 
@@ -208,10 +209,10 @@ def _set_cache(self):
             cachename = cache = self.fname
         else:
             if os.path.isabs(cf):
-                self._cache = cf
+                cache = cf
             else:
-                cdir = os.path.dirname(fname)
-                self._cache = os.path.join(cdir, cf)
+                cdir = os.path.dirname(self.fname)
+                cache = os.path.join(cdir, cf)
             cachename = cf
 
         return cache, cachename

tests/imageseries/test_formats.py

@@ -95,7 +95,17 @@ def test_fmtfc(self):
         """save/load frame-cache format"""
         imageseries.write(self.is_a, self.fcfile, self.fmt,
             threshold=self.thresh, cache_file=self.cache_file)
-        # is_fc = imageseries.open(self.fcfile, self.fmt, style='yml')
+        is_fc = imageseries.open(self.fcfile, self.fmt)
+        diff = compare(self.is_a, is_fc)
+        self.assertAlmostEqual(diff, 0., "frame-cache reconstruction failed")
+        self.assertTrue(compare_meta(self.is_a, is_fc))
+
+    def test_fmtfc_nocache_file(self):
+        """save/load frame-cache format with no cache_file arg"""
+        imageseries.write(
+            self.is_a, self.fcfile, self.fmt,
+            threshold=self.thresh
+        )
         is_fc = imageseries.open(self.fcfile, self.fmt)
         diff = compare(self.is_a, is_fc)
         self.assertAlmostEqual(diff, 0., "frame-cache reconstruction failed")