Merge f807bc3 into ebb1bdd

specutils/io/registers.py

@@ -48,19 +48,29 @@ def wrapper(*args, **kwargs):
                 return False
         return wrapper
 
-    identifier = identifier_wrapper(identifier)
-
     def decorator(func):
         io_registry.register_reader(label, dtype, func)
 
-        # If the identifier is not defined, but the extensions are, create
-        # a simple identifier based off file extension.
-        if identifier is None and extensions is not None:
-            io_registry.register_identifier(
-                label, dtype, lambda *args, **kwargs: any([args[0].endswith(x)
-                                                           for x in extensions]))
+        if identifier is None:
+            # If the identifier is not defined, but the extensions are, create
+            # a simple identifier based off file extension.
+            if extensions is not None:
+                logging.info("'{}' data loader provided for {} without "
+                             "explicit identifier. Creating identifier using "
+                             "list of compatible extensions".format(
+                                 label, dtype.__name__))
+                id_func = lambda *args, **kwargs: any([args[1].endswith(x)
+                                                          for x in extensions])
+            # Otherwise, create a dummy identifier
+            else:
+                logging.warning("'{}' data loader provided for {} without "
+                             "explicit identifier or list of compatible "
+                             "extensions".format(label, dtype.__name__))
+                id_func = lambda *args, **kwargs: True
         else:
-            io_registry.register_identifier(label, dtype, identifier)
+            id_func = identifier_wrapper(identifier)
+
+        io_registry.register_identifier(label, dtype, id_func)
 
         # Include the file extensions as attributes on the function object
         func.extensions = extensions
@@ -90,7 +100,7 @@ def load_spectrum_list(*args, **kwargs):
             load_spectrum_list.priority = priority
 
             io_registry.register_reader(label, SpectrumList, load_spectrum_list)
-            io_registry.register_identifier(label, SpectrumList, identifier)
+            io_registry.register_identifier(label, SpectrumList, id_func)
             logging.debug("Created SpectrumList reader for \"{}\".".format(label))
 
         @wraps(func)

specutils/tests/test_io.py

@@ -14,7 +14,8 @@
 import pytest
 import warnings
 
-from specutils import SpectrumList
+from specutils import Spectrum1D, SpectrumList
+from specutils.io import data_loader
 
 
 def test_generic_spectrum_from_table(recwarn):
@@ -71,3 +72,87 @@ def test_speclist_autoidentify():
 
     formats = registry.get_formats(SpectrumList)
     assert (formats['Auto-identify'] == 'Yes').all()
+
+
+def test_default_identifier(tmpdir):
+
+    fname = str(tmpdir.join('empty.txt'))
+    with open(fname, 'w') as ff:
+        ff.write('\n')
+
+    format_name = 'default_identifier_test'
+
+    @data_loader(format_name)
+    def reader(*args, **kwargs):
+        """Doesn't actually get used."""
+        return
+
+    for datatype in [Spectrum1D, SpectrumList]:
+        fmts = registry.identify_format('read', datatype, fname, None, [], {})
+        assert format_name in fmts
+
+        # Clean up after ourselves
+        registry.unregister_reader(format_name, datatype)
+        registry.unregister_identifier(format_name, datatype)
+
+
+def test_default_identifier_extension(tmpdir):
+
+    good_fname = str(tmpdir.join('empty.fits'))
+    bad_fname = str(tmpdir.join('empty.txt'))
+
+    # Create test data files.
+    for name in [good_fname, bad_fname]:
+        with open(name, 'w') as ff:
+            ff.write('\n')
+
+    format_name = 'default_identifier_extension_test'
+
+    @data_loader(format_name, extensions=['fits'])
+    def reader(*args, **kwargs):
+        """Doesn't actually get used."""
+        return
+
+    for datatype in [Spectrum1D, SpectrumList]:
+        fmts = registry.identify_format('read', datatype, good_fname, None, [], {})
+        assert format_name in fmts
+
+        fmts = registry.identify_format('read', datatype, bad_fname, None, [], {})
+        assert format_name not in fmts
+
+        # Clean up after ourselves
+        registry.unregister_reader(format_name, datatype)
+        registry.unregister_identifier(format_name, datatype)
+
+
+def test_custom_identifier(tmpdir):
+
+    good_fname = str(tmpdir.join('good.txt'))
+    bad_fname = str(tmpdir.join('bad.txt'))
+
+    # Create test data files.
+    for name in [good_fname, bad_fname]:
+        with open(name, 'w') as ff:
+            ff.write('\n')
+
+    format_name = 'custom_identifier_test'
+
+    def identifier(origin, *args, **kwargs):
+        fname = args[0]
+        return 'good' in fname
+
+    @data_loader(format_name, identifier=identifier)
+    def reader(*args, **kwargs):
+        """Doesn't actually get used."""
+        return
+
+    for datatype in [Spectrum1D, SpectrumList]:
+        fmts = registry.identify_format('read', datatype, good_fname, None, [], {})
+        assert format_name in fmts
+
+        fmts = registry.identify_format('read', datatype, bad_fname, None, [], {})
+        assert format_name not in fmts
+
+        # Clean up after ourselves
+        registry.unregister_reader(format_name, datatype)
+        registry.unregister_identifier(format_name, datatype)