PR: Improve validation for the right Spyder-kernels version

spyder/plugins/ipythonconsole/tests/test_ipythonconsole.py

@@ -2387,5 +2387,39 @@ def test_varexp_magic_dbg_locals(ipyconsole, qtbot):
     assert shell._control.toHtml().count('img src') == 1
 
 
+@pytest.mark.skipif(os.name == 'nt', reason="Fails on windows")
+def test_old_kernel_version(ipyconsole, qtbot):
+    """
+    Check that an error is shown when an version of spyder-kernels is used.
+    """
+    # Set a false _spyder_kernels_version in the cached kernel
+    w = ipyconsole.get_widget()
+    # create new client so PYTEST_CURRENT_TEST is the same
+    w.create_new_client()
+    # Wait until the window is fully up
+    shell = ipyconsole.get_current_shellwidget()
+    qtbot.waitUntil(
+        lambda: shell._prompt_html is not None, timeout=SHELL_TIMEOUT)
+
+    kc = w._cached_kernel_properties[-1][2]
+    kc.start_channels()
+    kc.execute("get_ipython()._spyder_kernels_version = '1.0.0'")
+    # Cleanup the kernel_client so it can be used again
+    kc.stop_channels()
+    kc._shell_channel = None
+    kc._iopub_channel = None
+    kc._stdin_channel = None
+    kc._hb_channel = None
+    kc._control_channel = None
+
+    # Create new client
+    w.create_new_client()
+    client = w.get_current_client()
+
+    # Make sure an error is shown
+    qtbot.waitUntil(lambda: client.error_text is not None)
+    assert 'version 1.0.0' in client.error_text
+
+
 if __name__ == "__main__":
     pytest.main()

spyder/plugins/ipythonconsole/widgets/__init__.py

@@ -19,10 +19,18 @@
 from .kernelconnect import KernelConnectionDialog
 from .restartdialog import ConsoleRestartDialog
 
+# Constant for different types of completion available
+COMPLETION_WIDGET_TYPE = {0: "droplist", 1: "ncurses", 2: "plain"}
+
+# Required version of Spyder-kernels
+# Define before ShellWidget
+SPYDER_KERNELS_MIN_VERSION = '2.3.0'
+SPYDER_KERNELS_MAX_VERSION = '2.4.0'
+SPYDER_KERNELS_VERSION = (
+    f'>={SPYDER_KERNELS_MIN_VERSION};<{SPYDER_KERNELS_MAX_VERSION}')
+
 # ShellWidget contains the other widgets and ClientWidget
 # contains it
 from .shell import ShellWidget
 from .client import ClientWidget
 
-# Constant for different types of completion available
-COMPLETION_WIDGET_TYPE = {0: "droplist", 1: "ncurses", 2: "plain"}

spyder/plugins/ipythonconsole/widgets/main_widget.py

@@ -40,7 +40,9 @@
 from spyder.plugins.ipythonconsole.utils.style import create_qss_style
 from spyder.plugins.ipythonconsole.widgets import (
     ClientWidget, ConsoleRestartDialog, COMPLETION_WIDGET_TYPE,
-    KernelConnectionDialog, PageControlWidget, ShellWidget)
+    KernelConnectionDialog, PageControlWidget, ShellWidget,
+    SPYDER_KERNELS_MIN_VERSION, SPYDER_KERNELS_MAX_VERSION,
+    SPYDER_KERNELS_VERSION)
 from spyder.py3compat import PY38_OR_MORE
 from spyder.utils import encoding, programs, sourcecode
 from spyder.utils.misc import get_error_match, remove_backslashes
@@ -58,10 +60,6 @@
 # ---- Constants
 # =============================================================================
 MAIN_BG_COLOR = QStylePalette.COLOR_BACKGROUND_1
-SPYDER_KERNELS_MIN_VERSION = '2.3.0'
-SPYDER_KERNELS_MAX_VERSION = '2.4.0'
-SPYDER_KERNELS_VERSION = (
-    f'>={SPYDER_KERNELS_MIN_VERSION};<{SPYDER_KERNELS_MAX_VERSION}')
 SPYDER_KERNELS_VERSION_MSG = _(
     '>= {0} and < {1}').format(
         SPYDER_KERNELS_MIN_VERSION, SPYDER_KERNELS_MAX_VERSION)
@@ -1644,16 +1642,13 @@ def create_client_for_kernel(self, connection_file, hostname, sshkey,
         # Assign kernel manager and client to shellwidget
         kernel_client.start_channels()
         shellwidget = client.shellwidget
+        if not known_spyder_kernel:
+            shellwidget.sig_is_spykernel.connect(
+                self.connect_external_spyder_kernel)
         shellwidget.set_kernel_client_and_manager(
             kernel_client, kernel_manager)
         shellwidget.sig_exception_occurred.connect(
             self.sig_exception_occurred)
-
-        if not known_spyder_kernel:
-            shellwidget.sig_is_spykernel.connect(
-                self.connect_external_spyder_kernel)
-            shellwidget.check_spyder_kernel()
-
         self.sig_shellwidget_created.emit(shellwidget)
         kernel_client.stopped_channels.connect(
             lambda: self.sig_shellwidget_deleted.emit(shellwidget))

spyder/plugins/ipythonconsole/widgets/shell.py

@@ -9,6 +9,7 @@
 """
 
 # Standard library imports
+import ast
 import os
 import os.path as osp
 import time
@@ -30,18 +31,22 @@
 from spyder.utils.palette import SpyderPalette
 from spyder.utils.clipboard_helper import CLIPBOARD_HELPER
 from spyder.utils import syntaxhighlighters as sh
+from spyder.utils.programs import check_version_range
 from spyder.plugins.ipythonconsole.utils.style import (
     create_qss_style, create_style_class)
 from spyder.widgets.helperwidgets import MessageCheckBox
 from spyder.plugins.ipythonconsole.comms.kernelcomm import KernelComm
 from spyder.plugins.ipythonconsole.widgets import (
     ControlWidget, DebuggingWidget, FigureBrowserWidget, HelpWidget,
-    NamepaceBrowserWidget, PageControlWidget)
+    NamepaceBrowserWidget, PageControlWidget, SPYDER_KERNELS_VERSION)
 
 
 MODULES_FAQ_URL = (
     "https://docs.spyder-ide.org/5/faq.html#using-packages-installer")
 
+ERROR_SPYDER_KERNEL_VERSION = _(
+    "Spyder kernel version {} not in required versions {}")
+
 
 class ShellWidget(NamepaceBrowserWidget, HelpWidget, DebuggingWidget,
                   FigureBrowserWidget):
@@ -247,6 +252,8 @@ def set_kernel_client_and_manager(self, kernel_client, kernel_manager):
         """Set the kernel client and manager"""
         self.kernel_manager = kernel_manager
         self.kernel_client = kernel_client
+        # Send message to kernel to check status
+        self.check_spyder_kernel()
         if self.is_spyder_kernel:
             # For completion
             kernel_client.control_channel.message_received.connect(
@@ -302,7 +309,7 @@ def is_running(self):
 
     def check_spyder_kernel(self):
         """Determine if the kernel is from Spyder."""
-        code = u"getattr(get_ipython().kernel, 'set_value', False)"
+        code = "getattr(get_ipython(), '_spyder_kernels_version', False)"
         if self._reading:
             return
         else:
@@ -318,8 +325,30 @@ def check_spyder_kernel_callback(self, reply):
         # Process kernel reply
         data = reply.get('data')
         if data is not None and 'text/plain' in data:
-            is_spyder_kernel = data['text/plain']
-            if 'SpyderKernel' in is_spyder_kernel:
+            version = ast.literal_eval(data['text/plain'])
+            if not version:
+                # The running_under_pytest() part can be removed when
+                # spyder-kernels 3 makes it into conda. This is needed for
+                # the test_conda_env_activation test
+                if running_under_pytest():
+                    return
+
+                if self.is_spyder_kernel:
+                    self.ipyclient.show_kernel_error(
+                        _("spyder_kernels version must be updated"))
+                return
+
+            if not check_version_range(version, SPYDER_KERNELS_VERSION):
+                if "dev0" not in version:
+                    # Development versions are acceptable
+                    self.ipyclient.show_kernel_error(
+                        ERROR_SPYDER_KERNEL_VERSION.format(
+                            version,
+                            SPYDER_KERNELS_VERSION
+                            ))
+                    return
+
+            if not self.is_spyder_kernel:
                 self.is_spyder_kernel = True
                 self.sig_is_spykernel.emit(self)
 

spyder/utils/programs.py

@@ -798,6 +798,29 @@ def run_terminal_thread():
         raise NotImplementedError
 
 
+def check_version_range(module_version, version):
+    """
+    Check version string of a module against a required version.
+    """
+    if ';' in version:
+        versions = version.split(';')
+    else:
+        versions = [version]
+
+    output = True
+    for _ver in versions:
+        match = re.search(r'[0-9]', _ver)
+        assert match is not None, "Invalid version number"
+        symb = _ver[:match.start()]
+        if not symb:
+            symb = '='
+        assert symb in ('>=', '>', '=', '<', '<='),\
+            "Invalid version condition '%s'" % symb
+        ver = _ver[match.start():]
+        output = output and check_version(module_version, ver, symb)
+    return output
+
+
 def check_version(actver, version, cmp_op):
     """
     Check version string of an active module against a required version.
@@ -924,23 +947,7 @@ def is_module_installed(module_name, version=None, interpreter=None,
     if version is None:
         return True
     else:
-        if ';' in version:
-            versions = version.split(';')
-        else:
-            versions = [version]
-
-        output = True
-        for _ver in versions:
-            match = re.search(r'[0-9]', _ver)
-            assert match is not None, "Invalid version number"
-            symb = _ver[:match.start()]
-            if not symb:
-                symb = '='
-            assert symb in ('>=', '>', '=', '<', '<='),\
-                "Invalid version condition '%s'" % symb
-            ver = _ver[match.start():]
-            output = output and check_version(module_version, ver, symb)
-        return output
+        return check_version_range(module_version, version)
 
 
 def is_python_interpreter_valid_name(filename):