Fix tab completion: quoted output broke matches

scilab_kernel/check.py

@@ -1,18 +1,19 @@
 import sys
+
 from metakernel import __version__ as mversion
+
 from . import __version__
 from .kernel import ScilabKernel
 
-
 if __name__ == "__main__":
-    print('Scilab kernel v%s' % __version__)
-    print('Metakernel v%s' % mversion)
-    print('Python v%s' % sys.version)
-    print('Python path: %s' % sys.executable)
+    print(f'Scilab kernel v{__version__}')
+    print(f'Metakernel v{mversion}')
+    print(f'Python v{sys.version}')
+    print(f'Python path: {sys.executable}')
     print('\nConnecting to Scilab...')
     try:
         s = ScilabKernel()
         print('Scilab connection established')
         print(s.banner)
-    except Exception as e:
+    except Exception as e:  # noqa: BLE001 -- diagnostic script: report any failure, don't crash with a raw traceback
         print(e)

scilab_kernel/kernel.py

@@ -1,25 +1,32 @@
-from __future__ import print_function, absolute_import
 
 import codecs
+import importlib
 import json
 import os
+import platform
 import re
 import shutil
+import subprocess
 import sys
-import platform
 import tempfile
-import importlib
-import subprocess
+from typing import ClassVar
+
 if importlib.util.find_spec('winreg'):
     import winreg
 from xml.dom import minidom
+from xml.parsers.expat import ExpatError
 
+from IPython.display import SVG, Image
 from metakernel import MetaKernel, ProcessMetaKernel, REPLWrapper, pexpect
 from metakernel.pexpect import which
-from IPython.display import Image, SVG
 
 from . import __version__
 
+# Scilab's terminal control codes (mode/cursor resets, backspace) end up
+# glued to the front of the *first* line of any console output -- used to
+# strip those out of completion results, see get_completions() below.
+_ANSI_ESCAPE_RE = re.compile(r'\x1b\[[0-9;]*[A-Za-z]|\x08')
+
 
 def get_kernel_json():
     """Get the kernel json for the kernel.
@@ -37,7 +44,7 @@ class ScilabKernel(ProcessMetaKernel):
     implementation_version = __version__,
     language = 'scilab'
     language_version = __version__,
-    language_info = {
+    language_info: ClassVar[dict] = {
         'name': 'scilab',
         'file_extension': '.sci',
         "mimetype": "text/x-scilab",
@@ -106,7 +113,7 @@ def _detect_executable(self):
         # read the windows registry
         if os.name == 'nt':
             try:
-                with winreg.OpenKey(winreg.HKEY_CLASSES_ROOT, "Scilab5.sce\shell\open\command") as key:
+                with winreg.OpenKey(winreg.HKEY_CLASSES_ROOT, r"Scilab5.sce\shell\open\command") as key:
                     cmd : str = winreg.EnumValue(key, 0)[1]
                     executable = cmd.split(r'"')[1].replace("wscilex.exe", "wscilex-cli.exe")
                     self.log.warning('Windows registry binary: ' + executable)
@@ -116,9 +123,9 @@ def _detect_executable(self):
 
         # detect macOS bundle
         if platform.system() == 'Darwin':
-            process = subprocess.run(['mdfind', '-onlyin', '/Applications', 'kMDItemCFBundleIdentifier=org.scilab.modules.jvm.Scilab'], 
-                                 stdout=subprocess.PIPE, 
-                                 universal_newlines=True)
+            process = subprocess.run(['mdfind', '-onlyin', '/Applications', 'kMDItemCFBundleIdentifier=org.scilab.modules.jvm.Scilab'],
+                                 stdout=subprocess.PIPE,
+                                 text=True, check=False)
             bundles = process.stdout
             if len(bundles) > 0:
                 executable = bundles.split('\n', 1)[0] + "/Contents/bin/scilab-adv-cli"
@@ -145,7 +152,7 @@ def makeWrapper(self):
         orig_prompt = r'-[0-9]*->'
         prompt_cmd = None
         change_prompt = None
-        continuation_prompt = '  \>'
+        continuation_prompt = r'  \>'
         self._first = True
         if os.name == 'nt':
             prompt_cmd = 'printf("-->")'
@@ -166,23 +173,23 @@ def makeWrapper(self):
 
     def Write(self, message):
         clean_msg = message.strip("\n\r\t")
-        super(ScilabKernel, self).Write(clean_msg)
+        super().Write(clean_msg)
 
     def Print(self, text):
         text = str(text).strip('\x1b[0m').replace('\u0008', '').strip()
         text = [line.strip() for line in text.splitlines()
                 if (not line.startswith(chr(27)))]
         text = '\n'.join(text)
         if text:
-            super(ScilabKernel, self).Print(text)
+            super().Print(text)
 
     def do_execute_direct(self, code, silent=False):
         if self._first:
             self._first = False
             self.handle_plot_settings()
             setup = self._setup.strip()
             self.do_execute_direct(setup, True)
-        resp = super(ScilabKernel, self).do_execute_direct(code, silent=silent)
+        resp = super().do_execute_direct(code, silent=silent)
         if silent:
             return resp
         if self.plot_settings.get('backend', None) == 'inline':
@@ -198,22 +205,33 @@ def get_kernel_help_on(self, info, level=0, none_on_fail=False):
                 return None
             else:
                 return ""
-        self.do_execute_direct('help %s' % obj, True)
+        self.do_execute_direct(f'help {obj}', True)
 
     def do_shutdown(self, restart):
         self.wrapper.sendline('quit')
-        super(ScilabKernel, self).do_shutdown(restart)
+        super().do_shutdown(restart)
 
     def get_completions(self, info):
         """
         Get completions from kernel based on info dict.
         """
-        cmd = 'completion("%s")' % info['obj']
+        obj = info['obj']
+        # completion() displays its result on Scilab's own console, quoted
+        # (Scilab now shows string arrays as `"a"  "b"  ...`), which broke
+        # the parsing below; printf("%s\n", ...) instead prints each match
+        # bare, one per line. Only printf when there is at least one match:
+        # it errors out on an empty array. Both calls run in the same
+        # persistent Scilab session as the user's own code, so nothing here
+        # is assigned to a variable that could shadow one of theirs.
+        cmd = (
+            f'if ~isempty(completion("{obj}")) then '
+            f'printf("%s\\n",completion("{obj}")); end'
+        )
         output = self.do_execute_direct(cmd, True)
         if not output:
             return []
-        output = output.output.replace('!', '')
-        return [line.strip() for line in output.splitlines()
+        text = _ANSI_ESCAPE_RE.sub('', output.output)
+        return [line.strip() for line in text.splitlines()
                 if info['obj'] in line]
 
     def handle_plot_settings(self):
@@ -238,17 +256,17 @@ def handle_plot_settings(self):
             try:
                 width, height = settings['size'].split(',')
                 width, height = int(width), int(height)
-            except Exception as e:
-                self.Error('Error setting plot settings: %s' % e)
+            except (ValueError, AttributeError) as e:
+                self.Error(f'Error setting plot settings: {e}')
 
-        cmds.append('h.figure_size = [%s,%s];' % (width, height))
-        cmds.append('h.axes_size = [%s * 0.98, %s * 0.8];' % (width, height))
+        cmds.append(f'h.figure_size = [{width},{height}];')
+        cmds.append(f'h.axes_size = [{width} * 0.98, {height} * 0.8];')
 
         if settings['backend'] == 'inline':
             cmds.append('h.visible = "off";')
         else:
             cmds.append('h.visible = "on";')
-        super(ScilabKernel, self).do_execute_direct('\n'.join(cmds), True)
+        super().do_execute_direct('\n'.join(cmds), True)
 
     def make_figures(self, plot_dir=None):
         """Create figures for the current figures.
@@ -267,7 +285,7 @@ def make_figures(self, plot_dir=None):
         plot_format = self._plot_fmt.lower()
         make_figs = '_make_figures("%s", "%s");'
         make_figs = make_figs % (plot_dir, plot_format)
-        super(ScilabKernel, self).do_execute_direct(make_figs, True)
+        super().do_execute_direct(make_figs, True)
         return plot_dir
 
     def extract_figures(self, plot_dir):
@@ -291,7 +309,7 @@ def extract_figures(self, plot_dir):
                 if self.error_handler:
                     self.error_handler(e)
                 else:
-                    raise e
+                    raise
         return images
 
     def _handle_svg(self, filename):
@@ -305,14 +323,14 @@ def _handle_svg(self, filename):
         im = SVG(data=data)
         try:
             im.data = self._fix_svg_size(im.data)
-        except Exception:
-            pass
+        except (ValueError, ExpatError) as e:
+            self.log.debug(f'Could not resize SVG (unexpected shape from GnuPlot?): {e}')
         try:
             settings = self.plot_settings
             if settings['antialiasing']:
                 im.data = self._fix_svg_antialiasing(im.data)
-        except Exception:
-            pass
+        except (ValueError, ExpatError) as e:
+            self.log.debug(f'Could not adjust SVG antialiasing (unexpected shape from GnuPlot?): {e}')
         return im
 
     def _fix_svg_size(self, data):
@@ -340,8 +358,8 @@ def _fix_svg_size(self, data):
                 width = width * settings['height'] / height
             height = settings['height']
 
-        svg.setAttribute('width', '%dpx' % width)
-        svg.setAttribute('height', '%dpx' % height)
+        svg.setAttribute('width', f'{int(width)}px')
+        svg.setAttribute('height', f'{int(height)}px')
         return svg.toxml()
 
     def _fix_svg_antialiasing(self, data):

scilab_kernel/magics/plot_magic.py

@@ -1,4 +1,6 @@
 from metakernel import Magic, option
+
+
 class ScilabPlotMagic(Magic):
 
     @option(

test_scilab_kernel.py

@@ -1,6 +1,8 @@
 """Example use of jupyter_kernel_test, with tests for IPython."""
 
 import unittest
+from typing import ClassVar
+
 import jupyter_kernel_test as jkt
 
 
@@ -11,12 +13,12 @@ class ScilabKernelTests(jkt.KernelTests):
 
     code_hello_world = "disp('hello, world')"
 
-    code_display_data = [
+    code_display_data: ClassVar[list] = [
         {'code': '%plot -f png\nplot([1,2,3])', 'mime': 'image/png'},
         {'code': '%plot -f svg\nplot([1,2,3])', 'mime': 'image/svg+xml'}
     ]
 
-    completion_samples = [
+    completion_samples: ClassVar[list] = [
         {
             'text': 'one',
             'matches': {'ones'},