Make importexport black-safe...

We do this by removing the fragile unicode characters (which
kind of isn't Python safe either), and test export *outside*
of the doctest hidden mechanism which was wrong (if expedient) also.

Author: rocky

mathics/builtin/files_io/importexport.py

@@ -1092,7 +1092,7 @@ class RegisterImport(Builtin):
 
     def apply(self, formatname, function, posts, evaluation, options):
         """ImportExport`RegisterImport[formatname_String, function_, posts_,
-                OptionsPattern[ImportExport`RegisterImport]]"""
+        OptionsPattern[ImportExport`RegisterImport]]"""
 
         if function.has_form("List", None):
             leaves = function.get_leaves()
@@ -1174,7 +1174,7 @@ class RegisterExport(Builtin):
 
     def apply(self, formatname, function, evaluation, options):
         """ImportExport`RegisterExport[formatname_String, function_,
-                OptionsPattern[ImportExport`RegisterExport]]"""
+        OptionsPattern[ImportExport`RegisterExport]]"""
         EXPORTERS[formatname.get_string_value()] = (function, options)
 
         return Symbol("Null")
@@ -1704,41 +1704,6 @@ class Export(Builtin):
 
     ## FORMATS
 
-    ## Text
-    #> Export["abc.txt", 1 + x + y]
-     = abc.txt
-    #> FilePrint[%]
-     | 1 + x + y
-    #> DeleteFile[%%]
-
-    #> Export["abc.txt", "ä", CharacterEncoding -> "ISOLatin1"];
-    #> strm = OpenRead["abc.txt", BinaryFormat -> True];
-    #> BinaryRead[strm]
-     = 195
-    #> Close[strm];
-    #> DeleteFile["abc.txt"];
-
-    #> Export["abc.txt", "ä", CharacterEncoding -> "UTF-8"];
-    #> strm = OpenRead["abc.txt", BinaryFormat -> True];
-    #> BinaryRead[strm]
-     = 195
-    #> Close[strm];
-    #> DeleteFile["abc.txt"];
-
-    ## CSV
-    #> Export["abc.csv", {{1, 2, 3}, {4, 5, 6}}]
-     = abc.csv
-    #> FilePrint[%]
-     | 1,2,3
-     | 4,5,6
-    #> DeleteFile[%%]
-
-    ## SVG
-    #> Export["sine.svg", Plot[Sin[x], {x,0,1}]]
-     = sine.svg
-    #> FileFormat[%]
-     = SVG
-    #> DeleteFile[%%]
     """
 
     messages = {
@@ -2193,12 +2158,6 @@ class B64Encode(Builtin):
      = Integrate[f[x], {x, 0, 2}]
     """
 
-    # mmatera: please put in pytest conditionally
-    # >> System`Convert`B64Dump`B64Encode["∫ f  x"]
-    #  = 4oirIGYg752MIHg=
-    # >> System`Convert`B64Dump`B64Decode[%]
-    #  = ∫ f  x
-
     context = "System`Convert`B64Dump`"
     name = "B64Encode"
 

test/test_importexport.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
-from .helper import check_evaluation
+import tempfile
+import os.path as osp
+from .helper import check_evaluation, session
 
 
 def test_import():
@@ -12,3 +14,45 @@ def test_import():
         ),
     ):
         check_evaluation(str_expr, str_expected, message)
+
+def test_export():
+
+    def run_export(temp_dirname: str, short_name: str, file_data:str, character_encoding):
+        file_path = osp.join(temp_dirname, short_name)
+        expr = f'Export["{file_path}", {file_data}'
+        expr += ', CharacterEncoding -> "{character_encoding}"' if character_encoding else ""
+        expr += "]"
+        result = session.evaluate(expr)
+        assert result.to_python() == f'"{file_path}"'
+        return file_path
+
+    def check_data(temp_dirname: str, short_name: str, file_data:str,
+                   character_encoding=None, expected_data=None):
+        file_path = run_export(temp_dirname, short_name, f'"{file_data}"', character_encoding)
+        if expected_data is None:
+            expected_data = file_data
+        assert open(file_path, "r").read() == expected_data
+
+
+    with tempfile.TemporaryDirectory() as temp_dirname:
+        # Check exporting text files (file extension ".txt")
+        check_data(temp_dirname, "add_expr.txt", "1 + x + y")
+        check_data(temp_dirname, "AAcute.txt", "\u00C1", "ISOLatin1")
+        check_data(temp_dirname, "AAcute.txt", "\u00C1", "UTF-8")
+
+        # Check exporting CSV files (file extension ".csv")
+        file_path = run_export(temp_dirname, "csv_list.csv", "{{1, 2, 3}, {4, 5, 6}}", None)
+        assert open(file_path, "r").read() == "1,2,3\n4,5,6"
+
+        # Check exporting SVG files (file extension ".svg")
+        file_path = run_export(temp_dirname, "sine.svg", "Plot[Sin[x], {x,0,1}]", None)
+        data = open(file_path, "r").read().strip()
+        assert data.startswith("<svg")
+        assert data.endswith("</svg>")
+
+# TODO:
+# mmatera: please put in pytest conditionally
+# >> System`Convert`B64Dump`B64Encode["∫ f  x"]
+#  = 4oirIGYg752MIHg=
+# >> System`Convert`B64Dump`B64Decode[%]
+#  = ∫ f  x