diff --git a/nw/__init__.py b/nw/__init__.py
index a5960f30..65ab7f59 100644
--- a/nw/__init__.py
+++ b/nw/__init__.py
@@ -246,19 +246,20 @@ def main(sysArgs=None):
         errorCode |= 32
 
     if errorData:
-        if not testMode:
-            errApp = QApplication([])
-            errMsg = QErrorMessage()
-            errMsg.resize(500, 300)
-            errMsg.showMessage((
-                "<h3>A critical error has been encountered</h3>"
-                "<p>novelWriter cannot start due to the following issues:<p>"
-                "<p>&nbsp;-&nbsp;%s</p>"
-                "<p>Shutting down ...</p>"
-            ) % (
-                "<br>&nbsp;-&nbsp;".join(errorData)
-            ))
-            errApp.exec_()
+        errApp = QApplication([])
+        errMsg = QErrorMessage()
+        errMsg.resize(500, 300)
+        errMsg.showMessage((
+            "<h3>A critical error has been encountered</h3>"
+            "<p>novelWriter cannot start due to the following issues:<p>"
+            "<p>&nbsp;-&nbsp;%s</p>"
+            "<p>Shutting down ...</p>"
+        ) % (
+            "<br>&nbsp;-&nbsp;".join(errorData)
+        ))
+        for errMsg in errorData:
+            logger.critical(errMsg)
+        errApp.exec_()
         sys.exit(errorCode)
 
     # Finish initialising config
@@ -293,4 +294,4 @@ def main(sysArgs=None):
         nwGUI = GuiMain()
         sys.exit(nwApp.exec_())
 
-    return
+# END Function main
diff --git a/nw/config.py b/nw/config.py
index 04c1a4db..9c232109 100644
--- a/nw/config.py
+++ b/nw/config.py
@@ -27,12 +27,12 @@
 
 import logging
 import configparser
+import shutil
 import json
 import sys
 import os
 
 from time import time
-from shutil import which
 
 from PyQt5.Qt import PYQT_VERSION_STR
 from PyQt5.QtCore import QT_VERSION_STR, QStandardPaths, QSysInfo
@@ -44,10 +44,11 @@ logger = logging.getLogger(__name__)
 
 class Config:
 
-    CNF_STR  = 0
-    CNF_INT  = 1
-    CNF_BOOL = 2
-    CNF_LIST = 3
+    CNF_STR   = 0
+    CNF_INT   = 1
+    CNF_BOOL  = 2
+    CNF_S_LST = 3
+    CNF_I_LST = 4
 
     def __init__(self):
 
@@ -211,12 +212,8 @@ class Config:
             self.osUnknown = True
 
         # Other System Info
-        if self.verQtValue >= 50600:
-            self.hostName  = QSysInfo.machineHostName()
-            self.kernelVer = QSysInfo.kernelVersion()
-        else:
-            self.hostName  = "Unknown"
-            self.kernelVer = "Unknown"
+        self.hostName  = "Unknown"
+        self.kernelVer = "Unknown"
 
         # Packages
         self.hasEnchant   = False # The pyenchant package
@@ -321,6 +318,11 @@ class Config:
                     self.errData.append(str(e))
                     self.dataPath = None
 
+        # Host and Kernel
+        if self.verQtValue >= 50600:
+            self.hostName  = QSysInfo.machineHostName()
+            self.kernelVer = QSysInfo.kernelVersion()
+
         # Load recent projects cache
         self.loadRecentCache()
 
@@ -388,25 +390,25 @@ class Config:
         ## Sizes
         cnfSec = "Sizes"
         self.winGeometry = self._parseLine(
-            cnfParse, cnfSec, "geometry", self.CNF_LIST, self.winGeometry
+            cnfParse, cnfSec, "geometry", self.CNF_I_LST, self.winGeometry
         )
         self.treeColWidth = self._parseLine(
-            cnfParse, cnfSec, "treecols", self.CNF_LIST, self.treeColWidth
+            cnfParse, cnfSec, "treecols", self.CNF_I_LST, self.treeColWidth
         )
         self.projColWidth = self._parseLine(
-            cnfParse, cnfSec, "projcols", self.CNF_LIST, self.projColWidth
+            cnfParse, cnfSec, "projcols", self.CNF_I_LST, self.projColWidth
         )
         self.mainPanePos = self._parseLine(
-            cnfParse, cnfSec, "mainpane", self.CNF_LIST, self.mainPanePos
+            cnfParse, cnfSec, "mainpane", self.CNF_I_LST, self.mainPanePos
         )
         self.docPanePos = self._parseLine(
-            cnfParse, cnfSec, "docpane", self.CNF_LIST, self.docPanePos
+            cnfParse, cnfSec, "docpane", self.CNF_I_LST, self.docPanePos
         )
         self.viewPanePos = self._parseLine(
-            cnfParse, cnfSec, "viewpane", self.CNF_LIST, self.viewPanePos
+            cnfParse, cnfSec, "viewpane", self.CNF_I_LST, self.viewPanePos
         )
         self.outlnPanePos = self._parseLine(
-            cnfParse, cnfSec, "outlinepane", self.CNF_LIST, self.outlnPanePos
+            cnfParse, cnfSec, "outlinepane", self.CNF_I_LST, self.outlnPanePos
         )
         self.isFullScreen = self._parseLine(
             cnfParse, cnfSec, "fullscreen", self.CNF_BOOL, self.isFullScreen
@@ -484,10 +486,10 @@ class Config:
             cnfParse, cnfSec, "autoscrollpos", self.CNF_INT, self.autoScrollPos
         )
         self.fmtSingleQuotes = self._parseLine(
-            cnfParse, cnfSec, "fmtsinglequote", self.CNF_LIST, self.fmtSingleQuotes
+            cnfParse, cnfSec, "fmtsinglequote", self.CNF_S_LST, self.fmtSingleQuotes
         )
         self.fmtDoubleQuotes = self._parseLine(
-            cnfParse, cnfSec, "fmtdoublequote", self.CNF_LIST, self.fmtDoubleQuotes
+            cnfParse, cnfSec, "fmtdoublequote", self.CNF_S_LST, self.fmtDoubleQuotes
         )
         self.spellTool = self._parseLine(
             cnfParse, cnfSec, "spelltool", self.CNF_STR, self.spellTool
@@ -901,23 +903,28 @@ class Config:
     #  Internal Functions
     ##
 
-    def _unpackList(self, inStr, listLen, listDefault, castTo=int):
-        """Unpack a comma separated string of items into a list.
-        """
-        inData = inStr.split(",")
-        outData = []
-        for i in range(listLen):
-            try:
-                outData.append(castTo(inData[i]))
-            except Exception:
-                outData.append(listDefault[i])
-        return outData
-
     def _packList(self, inData):
-        """Pack a list of items into a comma separated string.
+        """Pack a list of items into a comma-separated string.
         """
         return ", ".join([str(inVal) for inVal in inData])
 
+    def _unpackList(self, inStr, listDefault, cnfType):
+        """Unpack a comma-separated string of items into a list.
+        """
+        inData = inStr.split(",")
+        outData = listDefault.copy()
+        for i in range(min(len(inData), len(listDefault))):
+            try:
+                if cnfType == self.CNF_S_LST:
+                    outData[i] = inData[i].strip()
+                elif cnfType == self.CNF_I_LST:
+                    outData[i] = int(inData[i].strip())
+                else:
+                    continue
+            except Exception:
+                continue
+        return outData
+
     def _parseLine(self, cnfParse, cnfSec, cnfName, cnfType, cnfDefault):
         """Parse a line and return the correct datatype.
         """
@@ -930,18 +937,24 @@ class Config:
                         return cnfParse.getint(cnfSec, cnfName)
                     elif cnfType == self.CNF_BOOL:
                         return cnfParse.getboolean(cnfSec, cnfName)
-                    elif cnfType == self.CNF_LIST:
+                    elif cnfType == self.CNF_I_LST:
                         return self._unpackList(
-                            cnfParse.get(cnfSec, cnfName), len(cnfDefault), cnfDefault
+                            cnfParse.get(cnfSec, cnfName), cnfDefault, self.CNF_I_LST
+                        )
+                    elif cnfType == self.CNF_S_LST:
+                        return self._unpackList(
+                            cnfParse.get(cnfSec, cnfName), cnfDefault, self.CNF_S_LST
                         )
                 except ValueError as e:
                     logger.error("Failed to load value from config file.")
                     logger.error(str(e))
+                    return cnfDefault
 
         return cnfDefault
 
     def _checkNone(self, checkVal):
-        """Convert a string to a none type.
+        """Return a NoneType if the value correspomds to None, otherwise
+        return the value unchanged.
         """
         if checkVal is None:
             return None
@@ -961,10 +974,8 @@ class Config:
             self.hasEnchant = False
             logger.debug("Checking package 'pyenchant': Missing")
 
-        try:
-            self.hasAssistant = which("assistant")
-        except Exception:
-            self.hasAssistant = False
+        assistPath = shutil.which("assistant")
+        self.hasAssistant = assistPath is not None
         if self.hasAssistant:
             logger.debug("Checking executable 'assistant': Ok")
         else:
diff --git a/nw/error.py b/nw/error.py
index 988b49e6..24a802aa 100644
--- a/nw/error.py
+++ b/nw/error.py
@@ -135,10 +135,9 @@ class NWErrorMessage(QDialog):
 # END Class NWErrorMessage
 
 
-def exceptionHandler(exType, exValue, exTrace, testMode=False):
+def exceptionHandler(exType, exValue, exTrace):
     """Function to catch unhandled global exceptions.
     """
-    import nw
     import logging
     from traceback import print_tb
     from PyQt5.QtWidgets import qApp
@@ -160,8 +159,7 @@ def exceptionHandler(exType, exValue, exTrace, testMode=False):
 
         errMsg = NWErrorMessage(nwGUI)
         errMsg.setMessage(exType, exValue, exTrace)
-        if nw.CONFIG.showGUI:
-            errMsg.exec_()
+        errMsg.exec_()
 
         try:
             # Try a controlled shudown
@@ -173,10 +171,7 @@ def exceptionHandler(exType, exValue, exTrace, testMode=False):
             logger.critical("Could not close the project before exiting")
             logger.critical(str(e))
 
-        if testMode:
-            return errMsg.msgBody.toPlainText()
-        else:
-            qApp.exit(1)
+        qApp.exit(1)
 
     except Exception as e:
         logger.critical(str(e))
diff --git a/pytest.ini b/pytest.ini
index b61d59ec..c2278317 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -1,6 +1,6 @@
 [pytest]
 markers =
-    error: Test various error handling scenarios
+    base: Base functionality tests
     core: Core functionality tests
     gui: Qt5 GUI tests
     serial
diff --git a/tests/README.md b/tests/README.md
index cd1be55b..7d8e378d 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -61,6 +61,10 @@ The commands for the respective test categories are listed below.
 
 | Type | Test Target        | Source File(s)        | Marker    | Filter                |
 | :--- | :----------------- | :-------------------- | :-------- | :-------------------- |
+| Unit | Main function      | nw/\_\_init\_\_.py    | `-m base` | `-k testBaseInit`     |
+| Unit | Common functions   | nw/common.py          | `-m base` | `-k testBaseCommon`   |
+| Unit | Config class       | nw/config.py          | `-m base` | `-k testBaseConfig`   |
+| Unit | Error handlers     | nw/error.py           | `-m base` | `-k testBaseError`    |
 | Unit | Core functions     | nw/core/tools.py      | `-m core` | `-k testCoreTools`    |
 | Unit | NWDoc class        | nw/core/document.py   | `-m core` | `-k testCoreDocument` |
 | Unit | NWIndex class      | nw/core/index.py      | `-m core` | `-k testCoreIndex`    |
diff --git a/tests/conftest.py b/tests/conftest.py
index 0d66d0ea..ea9a92b3 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -73,6 +73,9 @@ def fncDir(tmpDir):
 def tmpConf(tmpDir):
     """Create a temporary novelWriter configuration object.
     """
+    confFile = os.path.join(tmpDir, "novelwriter.conf")
+    if os.path.isfile(confFile):
+        os.unlink(confFile)
     theConf = Config()
     theConf.initConfig(tmpDir, tmpDir)
     theConf.setLastPath("")
diff --git a/tests/dummy.py b/tests/dummy.py
index 0f26e0ff..daf0e070 100644
--- a/tests/dummy.py
+++ b/tests/dummy.py
@@ -13,7 +13,7 @@ class DummyMain():
         self.hasProject = True
         self.theIndex = None
         self.theProject = None
-        self.statusBar = StatusBar()
+        self.statusBar = DummyStatusBar()
 
         # Test Variables
         self.askResponse = True
@@ -42,6 +42,12 @@ class DummyMain():
     def rebuildIndex(self):
         return
 
+    def closeMain(self):
+        return "closeMain"
+
+    def close(self):
+        return "close"
+
     # Test Functions
 
     def undo(self):
@@ -52,9 +58,9 @@ class DummyMain():
         self.lastAlert = ""
         return
 
-# END Class GuiMain
+# END Class DummyMain
 
-class StatusBar():
+class DummyStatusBar():
 
     def __init__(self):
         return
@@ -62,7 +68,7 @@ class StatusBar():
     def setStatus(self, theText):
         return
 
-# END Class StatusBar
+# END Class DummyStatusBar
 
 # =========================================================================== #
 #  Error Functions
@@ -71,3 +77,6 @@ class StatusBar():
 
 def causeOSError(*args, **kwargs):
     raise OSError
+
+def causeException(*args, **kwargs):
+    raise Exception
diff --git a/tests/reference/novelwriter.conf b/tests/reference/baseConfig_novelwriter.conf
similarity index 100%
rename from tests/reference/novelwriter.conf
rename to tests/reference/baseConfig_novelwriter.conf
diff --git a/tests/reference/coreProject_2_nwProject.nwx b/tests/reference/coreProject_NewCustomA_nwProject.nwx
similarity index 100%
rename from tests/reference/coreProject_2_nwProject.nwx
rename to tests/reference/coreProject_NewCustomA_nwProject.nwx
diff --git a/tests/reference/coreProject_3_nwProject.nwx b/tests/reference/coreProject_NewCustomB_nwProject.nwx
similarity index 100%
rename from tests/reference/coreProject_3_nwProject.nwx
rename to tests/reference/coreProject_NewCustomB_nwProject.nwx
diff --git a/tests/reference/coreProject_5_nwProject.nwx b/tests/reference/coreProject_NewFile_nwProject.nwx
similarity index 100%
rename from tests/reference/coreProject_5_nwProject.nwx
rename to tests/reference/coreProject_NewFile_nwProject.nwx
diff --git a/tests/reference/coreProject_1_nwProject.nwx b/tests/reference/coreProject_NewMinimal_nwProject.nwx
similarity index 100%
rename from tests/reference/coreProject_1_nwProject.nwx
rename to tests/reference/coreProject_NewMinimal_nwProject.nwx
diff --git a/tests/reference/coreProject_4_nwProject.nwx b/tests/reference/coreProject_NewRoot_nwProject.nwx
similarity index 100%
rename from tests/reference/coreProject_4_nwProject.nwx
rename to tests/reference/coreProject_NewRoot_nwProject.nwx
diff --git a/tests/test_common.py b/tests/test_base_common.py
similarity index 78%
rename from tests/test_common.py
rename to tests/test_base_common.py
index 135627fc..8cdb8a74 100644
--- a/tests/test_common.py
+++ b/tests/test_base_common.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-"""novelWriter Common Class Tester
+"""novelWriter Common Functions Tester
 """
 
 import time
@@ -11,8 +11,10 @@ from nw.common import (
 )
 from tools import cmpList
 
-@pytest.mark.core
-def testCheckString():
+@pytest.mark.base
+def testBaseCommon_CheckString():
+    """Test the checkString function.
+    """
     assert checkString(None, "NotNone", True) is None
     assert checkString("None", "NotNone", True) is None
     assert checkString("None", "NotNone", False) == "None"
@@ -21,8 +23,12 @@ def testCheckString():
     assert checkString(1.0, "NotNone", False) == "NotNone"
     assert checkString(True, "NotNone", False) == "NotNone"
 
-@pytest.mark.core
-def testCheckInt():
+# END Test testBaseCommon_CheckString
+
+@pytest.mark.base
+def testBaseCommon_CheckInt():
+    """Test the checkInt function.
+    """
     assert checkInt(None, 3, True) is None
     assert checkInt("None", 3, True) is None
     assert checkInt(None, 3, False) == 3
@@ -30,8 +36,12 @@ def testCheckInt():
     assert checkInt(1.0, 3, False) == 1
     assert checkInt(True, 3, False) == 1
 
-@pytest.mark.core
-def testCheckBool():
+# END Test testBaseCommon_CheckInt
+
+@pytest.mark.base
+def testBaseCommon_CheckBool():
+    """Test the checkBool function.
+    """
     assert checkBool(None, 3, True) is None
     assert checkBool("None", 3, True) is None
     assert checkBool("True", False, False)
@@ -44,8 +54,12 @@ def testCheckBool():
     assert checkBool(1.0, None, False) is None
     assert checkBool(2.0, None, False) is None
 
-@pytest.mark.core
-def testCheckHandle():
+# END Test testBaseCommon_CheckBool
+
+@pytest.mark.base
+def testBaseCommon_CheckHandle():
+    """Test the checkHandle function.
+    """
     assert checkHandle("None", 1, True) is None
     assert checkHandle("None", 1, False) == 1
     assert checkHandle(None, 1, True) is None
@@ -53,8 +67,12 @@ def testCheckHandle():
     assert checkHandle("47666c91c7ccf", None, False) == "47666c91c7ccf"
     assert checkHandle("h7666c91c7ccf", None, False) is None
 
-@pytest.mark.core
-def testColRange():
+# END Test testBaseCommon_CheckHandle
+
+@pytest.mark.base
+def testBaseCommon_ColRange():
+    """Test the colRange function.
+    """
     assert colRange([0, 0], [0, 0], 0) is None
     assert cmpList(
         colRange([200, 50, 0], [50, 200, 0], 1),
@@ -77,14 +95,22 @@ def testColRange():
         [[200, 50, 0], [162, 87, 0], [124, 124, 0], [86, 161, 0], [50, 200, 0]]
     )
 
-@pytest.mark.core
-def testFormatTimeStamp():
+# END Test testBaseCommon_ColRange
+
+@pytest.mark.base
+def testBaseCommon_FormatTimeStamp():
+    """Test the formatTimeStamp function.
+    """
     tTime = time.mktime(time.gmtime(0))
     assert formatTimeStamp(tTime, False) == "1970-01-01 00:00:00"
     assert formatTimeStamp(tTime, True) == "1970-01-01 00.00.00"
 
-@pytest.mark.core
-def testFormatTime():
+# END Test testBaseCommon_FormatTimeStamp
+
+@pytest.mark.base
+def testBaseCommon_FormatTime():
+    """Test the formatTime function.
+    """
     assert formatTime("1") == "ERROR"
     assert formatTime(1.0) == "ERROR"
     assert formatTime(1) == "00:00:01"
@@ -101,8 +127,12 @@ def testFormatTime():
     assert formatTime(86400) == "1-00:00:00"
     assert formatTime(360000) == "4-04:00:00"
 
-@pytest.mark.core
-def testFormatInt():
+# END Test testBaseCommon_FormatTime
+
+@pytest.mark.base
+def testBaseCommon_FormatInt():
+    """Test the formatInt function.
+    """
     assert formatInt(1000) == "1000"
     assert formatInt(1234) == "1.23\u2009k"
     assert formatInt(12345) == "12.3\u2009k"
@@ -112,8 +142,12 @@ def testFormatInt():
     assert formatInt(123456789) == "123\u2009M"
     assert formatInt(1234567890) == "1.23\u2009G"
 
-@pytest.mark.core
-def testTransferCase():
+# END Test testBaseCommon_FormatInt
+
+@pytest.mark.base
+def testBaseCommon_TransferCase():
+    """Test the transferCase function.
+    """
     assert transferCase(1, "TaRgEt") == "TaRgEt"
     assert transferCase("source", 1) == 1
     assert transferCase("", "TaRgEt") == "TaRgEt"
@@ -122,8 +156,12 @@ def testTransferCase():
     assert transferCase("SOURCE", "target") == "TARGET"
     assert transferCase("source", "TARGET") == "target"
 
-@pytest.mark.core
-def testFuzzyTime():
+# END Test testBaseCommon_TransferCase
+
+@pytest.mark.base
+def testBaseCommon_FuzzyTime():
+    """Test the fuzzyTime function.
+    """
     assert fuzzyTime(-1) == "in the future"
     assert fuzzyTime(0) == "just now"
     assert fuzzyTime(29) == "just now"
@@ -152,3 +190,5 @@ def testFuzzyTime():
     assert fuzzyTime(29808000) == "a year ago"
     assert fuzzyTime(47336399) == "a year ago"
     assert fuzzyTime(47336400) == "2 years ago"
+
+# END Test testBaseCommon_FuzzyTime
diff --git a/tests/test_base_config.py b/tests/test_base_config.py
new file mode 100644
index 00000000..fe755646
--- /dev/null
+++ b/tests/test_base_config.py
@@ -0,0 +1,505 @@
+# -*- coding: utf-8 -*-
+"""novelWriter Config Class Tester
+"""
+
+import pytest
+import sys
+import os
+import configparser
+
+from shutil import copyfile
+
+from dummy import causeOSError
+from tools import cmpFiles
+
+from nw.config import Config
+from nw.constants import nwConst, nwFiles
+
+@pytest.mark.base
+def testBaseConfig_Constructor(monkeypatch):
+    """Test config contructor.
+    """
+    # Linux
+    monkeypatch.setattr("sys.platform", "linux")
+    tstConf = Config()
+    assert tstConf.osLinux is True
+    assert tstConf.osDarwin is False
+    assert tstConf.osWindows is False
+    assert tstConf.osUnknown is False
+    monkeypatch.undo()
+
+    # macOS
+    monkeypatch.setattr("sys.platform", "darwin")
+    tstConf = Config()
+    assert tstConf.osLinux is False
+    assert tstConf.osDarwin is True
+    assert tstConf.osWindows is False
+    assert tstConf.osUnknown is False
+    monkeypatch.undo()
+
+    # Windows
+    monkeypatch.setattr("sys.platform", "win32")
+    tstConf = Config()
+    assert tstConf.osLinux is False
+    assert tstConf.osDarwin is False
+    assert tstConf.osWindows is True
+    assert tstConf.osUnknown is False
+    monkeypatch.undo()
+
+    # Cygwin
+    monkeypatch.setattr("sys.platform", "cygwin")
+    tstConf = Config()
+    assert tstConf.osLinux is False
+    assert tstConf.osDarwin is False
+    assert tstConf.osWindows is True
+    assert tstConf.osUnknown is False
+    monkeypatch.undo()
+
+    # Other
+    monkeypatch.setattr("sys.platform", "some_ther_os")
+    tstConf = Config()
+    assert tstConf.osLinux is False
+    assert tstConf.osDarwin is False
+    assert tstConf.osWindows is False
+    assert tstConf.osUnknown is True
+    monkeypatch.undo()
+
+# END Test testBaseConfig_Constructor
+
+@pytest.mark.base
+def testBaseConfig_Init(monkeypatch, tmpDir, fncDir, outDir, refDir):
+    """Test config intialisation.
+    """
+    tstConf = Config()
+
+    confFile = os.path.join(tmpDir, "novelwriter.conf")
+    testFile = os.path.join(outDir, "baseConfig_novelwriter.conf")
+    compFile = os.path.join(refDir, "baseConfig_novelwriter.conf")
+
+    # Make sure we don't have any old conf file
+    if os.path.isfile(confFile):
+        os.unlink(confFile)
+
+    # Let the config class figure out the path
+    monkeypatch.setattr("PyQt5.QtCore.QStandardPaths.writableLocation", lambda *args: fncDir)
+    tstConf.verQtValue = 50600
+    tstConf.initConfig()
+    assert tstConf.confPath == os.path.join(fncDir, tstConf.appHandle)
+    assert tstConf.dataPath == os.path.join(fncDir, tstConf.appHandle)
+    assert not os.path.isfile(confFile)
+    tstConf.verQtValue = 50000
+    tstConf.initConfig()
+    assert tstConf.confPath == os.path.join(fncDir, tstConf.appHandle)
+    assert tstConf.dataPath == os.path.join(fncDir, tstConf.appHandle)
+    assert not os.path.isfile(confFile)
+    monkeypatch.undo()
+
+    # Fail to make folders
+    monkeypatch.setattr("os.mkdir", causeOSError)
+
+    tstConfDir = os.path.join(fncDir, "test_conf")
+    tstConf.initConfig(confPath=tstConfDir, dataPath=tmpDir)
+    assert tstConf.confPath is None
+    assert tstConf.dataPath == tmpDir
+    assert not os.path.isfile(confFile)
+
+    tstDataDir = os.path.join(fncDir, "test_data")
+    tstConf.initConfig(confPath=tmpDir, dataPath=tstDataDir)
+    assert tstConf.confPath == tmpDir
+    assert tstConf.dataPath is None
+    assert os.path.isfile(confFile)
+    os.unlink(confFile)
+
+    monkeypatch.undo()
+
+    # Test load/save with no path
+    tstConf.confPath = None
+    assert not tstConf.loadConfig()
+    assert not tstConf.saveConfig()
+
+    # Run again and set the paths directly and correctly
+    # This should create a config file as well
+    monkeypatch.setattr("os.path.expanduser", lambda *args: "")
+    tstConf.spellTool = nwConst.SP_INTERNAL
+    tstConf.initConfig(confPath=tmpDir, dataPath=tmpDir)
+    assert tstConf.confPath == tmpDir
+    assert tstConf.dataPath == tmpDir
+    assert os.path.isfile(confFile)
+
+    copyfile(confFile, testFile)
+    assert cmpFiles(testFile, compFile, [2, 9])
+    monkeypatch.undo()
+
+    # Load and save with OSError
+    monkeypatch.setattr("builtins.open", causeOSError)
+
+    assert not tstConf.loadConfig()
+    assert tstConf.hasError is True
+    assert tstConf.errData != []
+    assert tstConf.getErrData().startswith("Could not")
+    assert tstConf.hasError is False
+    assert tstConf.errData == []
+
+    assert not tstConf.saveConfig()
+    assert tstConf.hasError is True
+    assert tstConf.errData != []
+    assert tstConf.getErrData().startswith("Could not")
+    assert tstConf.hasError is False
+    assert tstConf.errData == []
+
+    monkeypatch.undo()
+
+    assert tstConf.loadConfig()
+    assert tstConf.saveConfig()
+
+    copyfile(confFile, testFile)
+    assert cmpFiles(testFile, compFile, [2, 9])
+
+# END Test testBaseConfig_Init
+
+@pytest.mark.base
+def testBaseConfig_RecentCache(monkeypatch, tmpConf, tmpDir, fncDir):
+    """Test recent cache file.
+    """
+    # Check failing
+    tmpConf.dataPath = None
+    assert not tmpConf.loadRecentCache()
+    assert not tmpConf.saveRecentCache()
+    tmpConf.dataPath = tmpDir
+
+    # Add a couple of values
+    pathOne = os.path.join(fncDir, "projPathOne", nwFiles.PROJ_FILE)
+    pathTwo = os.path.join(fncDir, "projPathTwo", nwFiles.PROJ_FILE)
+    assert tmpConf.updateRecentCache(pathOne, "Proj One", 100, 1600002000)
+    assert tmpConf.updateRecentCache(pathTwo, "Proj Two", 200, 1600005600)
+    assert tmpConf.recentProj == {
+        pathOne: {"time": 1600002000, "title": "Proj One", "words": 100},
+        pathTwo: {"time": 1600005600, "title": "Proj Two", "words": 200},
+    }
+
+    # Fail to Save
+    monkeypatch.setattr("builtins.open", causeOSError)
+    assert not tmpConf.saveRecentCache()
+    monkeypatch.undo()
+
+    # Save Proper
+    cacheFile = os.path.join(tmpDir, nwFiles.RECENT_FILE)
+    assert tmpConf.saveRecentCache()
+    assert tmpConf.saveRecentCache()
+    assert os.path.isfile(cacheFile)
+
+    # Fail to Load
+    monkeypatch.setattr("builtins.open", causeOSError)
+    tmpConf.recentProj = {}
+    assert not tmpConf.loadRecentCache()
+    assert tmpConf.recentProj == {}
+    monkeypatch.undo()
+
+    # Load Proper
+    tmpConf.recentProj = {}
+    assert tmpConf.loadRecentCache()
+    assert tmpConf.recentProj == {
+        pathOne: {"time": 1600002000, "title": "Proj One", "words": 100},
+        pathTwo: {"time": 1600005600, "title": "Proj Two", "words": 200},
+    }
+
+    # Remove Non-Existent Entry
+    assert not tmpConf.removeFromRecentCache("dummy")
+    assert tmpConf.recentProj == {
+        pathOne: {"time": 1600002000, "title": "Proj One", "words": 100},
+        pathTwo: {"time": 1600005600, "title": "Proj Two", "words": 200},
+    }
+
+    # Remove Second Entry
+    assert tmpConf.removeFromRecentCache(pathTwo)
+    assert tmpConf.recentProj == {
+        pathOne: {"time": 1600002000, "title": "Proj One", "words": 100},
+    }
+
+# END Test testBaseConfig_RecentCache
+
+@pytest.mark.base
+def testBaseConfig_SetPath(tmpConf, tmpDir):
+    """Test path setters.
+    """
+    # Conf Path
+    assert tmpConf.setConfPath(None)
+    assert not tmpConf.setConfPath(os.path.join("somewhere", "over", "the", "rainbow"))
+    assert tmpConf.setConfPath(os.path.join(tmpDir, "novelwriter.conf"))
+    assert tmpConf.confPath == tmpDir
+    assert tmpConf.confFile == "novelwriter.conf"
+    assert not tmpConf.confChanged
+
+    # Data Path
+    assert tmpConf.setDataPath(None)
+    assert not tmpConf.setDataPath(os.path.join("somewhere", "over", "the", "rainbow"))
+    assert tmpConf.setDataPath(tmpDir)
+    assert tmpConf.dataPath == tmpDir
+    assert not tmpConf.confChanged
+
+    # Last Path
+    assert tmpConf.setLastPath(None)
+    assert tmpConf.lastPath == ""
+
+    assert tmpConf.setLastPath(os.path.join(tmpDir, "file.tmp"))
+    assert tmpConf.lastPath == tmpDir
+
+    assert tmpConf.setLastPath("")
+    assert tmpConf.lastPath == ""
+
+# END Test testBaseConfig_SetPath
+
+@pytest.mark.base
+def testBaseConfig_SettersGetters(tmpConf, tmpDir, outDir, refDir):
+    """Set various sizes and positions
+    """
+    confFile = os.path.join(tmpDir, "novelwriter.conf")
+    testFile = os.path.join(outDir, "baseConfig_novelwriter.conf")
+    compFile = os.path.join(refDir, "baseConfig_novelwriter.conf")
+
+    # GUI Scaling
+    # ===========
+    tmpConf.guiScale = 1.0
+    assert tmpConf.pxInt(10) == 10
+    assert tmpConf.pxInt(13) == 13
+    assert tmpConf.rpxInt(10) == 10
+    assert tmpConf.rpxInt(13) == 13
+
+    tmpConf.guiScale = 2.0
+    assert tmpConf.pxInt(10) == 20
+    assert tmpConf.pxInt(13) == 26
+    assert tmpConf.rpxInt(10) == 5
+    assert tmpConf.rpxInt(13) == 6
+
+    # Setter + Getter Combos
+    # ======================
+
+    # Window Size
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setWinSize(1205, 655)
+    assert not tmpConf.confChanged
+
+    tmpConf.guiScale = 2.0
+    assert tmpConf.setWinSize(70, 70)
+    assert tmpConf.getWinSize() == [70, 70]
+    assert tmpConf.winGeometry == [35, 35]
+
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setWinSize(70, 70)
+    assert tmpConf.getWinSize() == [70, 70]
+    assert tmpConf.winGeometry == [70, 70]
+
+    assert tmpConf.setWinSize(1200, 650)
+
+    # Project Tree Columns
+    tmpConf.guiScale = 2.0
+    assert tmpConf.setTreeColWidths([10, 20, 25])
+    assert tmpConf.getTreeColWidths() == [10, 20, 24]
+    assert tmpConf.treeColWidth == [5, 10, 12]
+
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setTreeColWidths([10, 20, 25])
+    assert tmpConf.getTreeColWidths() == [10, 20, 25]
+    assert tmpConf.treeColWidth == [10, 20, 25]
+
+    assert tmpConf.setTreeColWidths([200, 50, 30])
+
+    # Project Settings Tree Columns
+    tmpConf.guiScale = 2.0
+    assert tmpConf.setProjColWidths([10, 20, 30])
+    assert tmpConf.getProjColWidths() == [10, 20, 30]
+    assert tmpConf.projColWidth == [5, 10, 15]
+
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setProjColWidths([10, 20, 30])
+    assert tmpConf.getProjColWidths() == [10, 20, 30]
+    assert tmpConf.projColWidth == [10, 20, 30]
+
+    assert tmpConf.setProjColWidths([200, 60, 140])
+
+    # Main Pane Splitter
+    tmpConf.guiScale = 2.0
+    assert tmpConf.setMainPanePos([200, 700])
+    assert tmpConf.getMainPanePos() == [200, 700]
+    assert tmpConf.mainPanePos == [100, 350]
+
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setMainPanePos([200, 700])
+    assert tmpConf.getMainPanePos() == [200, 700]
+    assert tmpConf.mainPanePos == [200, 700]
+
+    assert tmpConf.setMainPanePos([300, 800])
+
+    # Doc Pane Splitter
+    tmpConf.guiScale = 2.0
+    assert tmpConf.setDocPanePos([300, 300])
+    assert tmpConf.getDocPanePos() == [300, 300]
+    assert tmpConf.docPanePos == [150, 150]
+
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setDocPanePos([300, 300])
+    assert tmpConf.getDocPanePos() == [300, 300]
+    assert tmpConf.docPanePos == [300, 300]
+
+    assert tmpConf.setDocPanePos([400, 400])
+
+    # View Pane Splitter
+    tmpConf.guiScale = 2.0
+    assert tmpConf.setViewPanePos([400, 250])
+    assert tmpConf.getViewPanePos() == [400, 250]
+    assert tmpConf.viewPanePos == [200, 125]
+
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setViewPanePos([400, 250])
+    assert tmpConf.getViewPanePos() == [400, 250]
+    assert tmpConf.viewPanePos == [400, 250]
+
+    assert tmpConf.setViewPanePos([500, 150])
+
+    # Outline Pane Splitter
+    tmpConf.guiScale = 2.0
+    assert tmpConf.setOutlinePanePos([400, 250])
+    assert tmpConf.getOutlinePanePos() == [400, 250]
+    assert tmpConf.outlnPanePos == [200, 125]
+
+    tmpConf.guiScale = 1.0
+    assert tmpConf.setOutlinePanePos([400, 250])
+    assert tmpConf.getOutlinePanePos() == [400, 250]
+    assert tmpConf.outlnPanePos == [400, 250]
+
+    assert tmpConf.setOutlinePanePos([500, 150])
+
+    # Getters Only
+    # ============
+    tmpConf.guiScale = 1.0
+    assert tmpConf.getTextWidth() == 600
+    assert tmpConf.getTextMargin() == 40
+    assert tmpConf.getTabWidth() == 40
+    assert tmpConf.getFocusWidth() == 800
+
+    tmpConf.guiScale = 2.0
+    assert tmpConf.getTextWidth() == 1200
+    assert tmpConf.getTextMargin() == 80
+    assert tmpConf.getTabWidth() == 80
+    assert tmpConf.getFocusWidth() == 1600
+
+    # Flag Setters
+    # ============
+    assert not tmpConf.setShowRefPanel(False)
+    assert not tmpConf.showRefPanel
+    assert tmpConf.setShowRefPanel(True)
+
+    assert not tmpConf.setViewComments(False)
+    assert not tmpConf.viewComments
+    assert tmpConf.setViewComments(True)
+
+    assert not tmpConf.setViewSynopsis(False)
+    assert not tmpConf.viewSynopsis
+    assert tmpConf.setViewSynopsis(True)
+
+    # Check Final File
+    # ================
+
+    assert tmpConf.confChanged
+    assert tmpConf.saveConfig()
+    assert not tmpConf.confChanged
+
+    copyfile(confFile, testFile)
+    assert cmpFiles(testFile, compFile, [2, 9])
+
+# END Test testBaseConfig_SettersGetters
+
+@pytest.mark.base
+def testBaseConfig_Internal(monkeypatch, tmpConf):
+    """Check internal functions.
+    """
+    # Function _packList
+    assert tmpConf._packList(["A", 1, 2.0, None, False]) == "A, 1, 2.0, None, False"
+
+    # Function _unpackList
+    assert tmpConf._unpackList("1, 2, 3", [0, 0, 0], tmpConf.CNF_I_LST) == [1, 2, 3]
+    assert tmpConf._unpackList("1, 2   ", [0, 0, 0], tmpConf.CNF_I_LST) == [1, 2, 0]
+    assert tmpConf._unpackList("A, B, C", [0, 0, 0], tmpConf.CNF_I_LST) == [0, 0, 0]
+    assert tmpConf._unpackList("1, 2, 3", ["X", "Y", "Z"], tmpConf.CNF_S_LST) == ["1", "2", "3"]
+    assert tmpConf._unpackList("A, B   ", ["X", "Y", "Z"], tmpConf.CNF_S_LST) == ["A", "B", "Z"]
+    assert tmpConf._unpackList("A, B, C", ["X", "Y", "Z"], tmpConf.CNF_S_LST) == ["A", "B", "C"]
+    assert tmpConf._unpackList("A, B, C", ["X", "Y", "Z"], tmpConf.CNF_STR) == ["X", "Y", "Z"]
+
+    # Function _parseLine
+    cnfParse = configparser.ConfigParser()
+    cnfParse.read_string(
+        "[Main]\n"
+        "val_string = dummy\n"
+        "val_int = 123\n"
+        "val_bool = True\n"
+        "val_list_string = A, B, C\n"
+        "val_list_int = 1, 2, 3\n"
+    )
+
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "val_string", tmpConf.CNF_STR, "default"
+    ) == "dummy"
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "nope", tmpConf.CNF_STR, "default"
+    ) == "default"
+
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "val_int", tmpConf.CNF_INT, "0"
+    ) == 123
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "nope", tmpConf.CNF_INT, 0
+    ) == 0
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "val_string", tmpConf.CNF_INT, 0
+    ) == 0
+
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "val_bool", tmpConf.CNF_BOOL, False
+    ) is True
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "nope", tmpConf.CNF_BOOL, False
+    ) is False
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "val_string", tmpConf.CNF_BOOL, False
+    ) is False
+
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "val_list_string", tmpConf.CNF_S_LST, ["W", "X", "Y", "Z"]
+    ) == ["A", "B", "C", "Z"]
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "nope", tmpConf.CNF_S_LST, ["W", "X", "Y", "Z"]
+    ) == ["W", "X", "Y", "Z"]
+
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "val_list_int", tmpConf.CNF_I_LST, [6, 7, 8, 9]
+    ) == [1, 2, 3, 9]
+    assert tmpConf._parseLine(
+        cnfParse, "Main", "nope", tmpConf.CNF_S_LST, [6, 7, 8, 9]
+    ) == [6, 7, 8, 9]
+
+    # Function _checkNone
+    assert tmpConf._checkNone(None) is None
+    assert tmpConf._checkNone("None") is None
+    assert tmpConf._checkNone("stuff") == "stuff"
+
+    # Function _checkOptionalPackages
+    # (Assumes enchant package exists ans is importable)
+    tmpConf._checkOptionalPackages()
+    assert tmpConf.hasEnchant is True
+
+    monkeypatch.setitem(sys.modules, "enchant", None)
+    tmpConf._checkOptionalPackages()
+    assert tmpConf.hasEnchant is False
+    monkeypatch.undo()
+
+    monkeypatch.setattr("shutil.which", lambda *args: "dummy")
+    tmpConf._checkOptionalPackages()
+    assert tmpConf.hasAssistant is True
+    monkeypatch.undo()
+
+    monkeypatch.setattr("shutil.which", lambda *args: None)
+    tmpConf._checkOptionalPackages()
+    assert tmpConf.hasAssistant is False
+    monkeypatch.undo()
+
+# END Test testBaseConfig_Internal
diff --git a/tests/test_base_error.py b/tests/test_base_error.py
new file mode 100644
index 00000000..472faaa2
--- /dev/null
+++ b/tests/test_base_error.py
@@ -0,0 +1,97 @@
+# -*- coding: utf-8 -*-
+"""novelWriter Error Tester
+"""
+
+import nw
+import pytest
+
+from PyQt5.QtWidgets import qApp
+
+from dummy import causeException
+
+from nw.error import NWErrorMessage, exceptionHandler
+
+@pytest.mark.base
+def testBaseError_Dialog(qtbot, monkeypatch, fncDir, tmpDir):
+    """Test the error dialog.
+    """
+    qApp.closeAllWindows()
+    nwGUI = nw.main(["--testmode", "--config=%s" % fncDir, "--data=%s" % tmpDir])
+    qtbot.addWidget(nwGUI)
+    nwGUI.show()
+    qtbot.waitForWindowShown(nwGUI)
+
+    nwErr = NWErrorMessage(nwGUI)
+    qtbot.addWidget(nwErr)
+    nwErr.show()
+
+    # Invalid Error Message
+    nwErr.setMessage(Exception, "Faulty Error", 123)
+    assert nwErr.msgBody.toPlainText() == "Failed to generate error report ..."
+
+    # Valid Error Message
+    monkeypatch.setattr("PyQt5.QtCore.QSysInfo.kernelVersion", lambda: "1.2.3")
+    nwErr.setMessage(Exception, "Fine Error", None)
+    theMessage = nwErr.msgBody.toPlainText()
+    assert theMessage
+    assert "Fine Error" in theMessage
+    assert "Exception" in theMessage
+    assert "(1.2.3)" in theMessage
+    monkeypatch.undo()
+
+    # No kernel version retrieved
+    monkeypatch.setattr("PyQt5.QtCore.QSysInfo.kernelVersion", causeException)
+    nwErr.setMessage(Exception, "Almost Fine Error", None)
+    theMessage = nwErr.msgBody.toPlainText()
+    assert theMessage
+    assert "(Unknown)" in theMessage
+    monkeypatch.undo()
+
+    nwErr._doClose()
+    nwErr.close()
+    nwGUI.closeMain()
+
+# END Test testBaseError_Dialog
+
+@pytest.mark.base
+def testBaseError_Handler(qtbot, monkeypatch, fncDir, tmpDir):
+    """Test the error handler. This test doesn'thave any asserts, but it
+    checks that the error handler handles potential exceptions. The test
+    will fail if excpetions are not handled.
+    """
+    qApp.closeAllWindows()
+    nwGUI = nw.main(["--testmode", "--config=%s" % fncDir, "--data=%s" % tmpDir])
+    qtbot.addWidget(nwGUI)
+    nwGUI.show()
+    qtbot.waitForWindowShown(nwGUI)
+
+    # Normal shutdown
+    monkeypatch.setattr(NWErrorMessage, "exec_", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.qApp.exit", lambda *args: None)
+    exceptionHandler(Exception, "Error Message", None)
+    monkeypatch.undo()
+
+    # Should not crash when no GUI is found
+    monkeypatch.setattr(NWErrorMessage, "exec_", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.qApp.exit", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.qApp.topLevelWidgets", lambda: [])
+    exceptionHandler(Exception, "Error Message", None)
+    monkeypatch.undo()
+
+    # Should handle qApp failing
+    monkeypatch.setattr(NWErrorMessage, "exec_", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.qApp.exit", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.qApp.topLevelWidgets", causeException)
+    exceptionHandler(Exception, "Error Message", None)
+    monkeypatch.undo()
+
+    # Should handle failing to close main GUI
+    monkeypatch.setattr(NWErrorMessage, "exec_", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.qApp.exit", lambda *args: None)
+    monkeypatch.setattr(nwGUI, "closeMain", causeException)
+    exceptionHandler(Exception, "Error Message", None)
+    monkeypatch.undo()
+
+    nwGUI.closeMain()
+
+# END Test testBaseError_Handler
diff --git a/tests/test_base_init.py b/tests/test_base_init.py
new file mode 100644
index 00000000..b691bfa1
--- /dev/null
+++ b/tests/test_base_init.py
@@ -0,0 +1,163 @@
+# -*- coding: utf-8 -*-
+"""novelWriter Main Init Tester
+"""
+
+import nw
+import pytest
+import logging
+import sys
+
+from dummy import DummyMain
+
+@pytest.mark.base
+def testBaseInit_Launch(caplog, monkeypatch, tmpDir):
+    """Check launching the main GUI.
+    """
+    monkeypatch.setattr("nw.guimain.GuiMain", DummyMain)
+
+    # Testmode launch
+    nwGUI = nw.main(
+        ["--testmode", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+    )
+    assert isinstance(nwGUI, DummyMain)
+
+    # Darwin launch
+    monkeypatch.setitem(sys.modules, "Foundation", None)
+    osDarwin = nw.CONFIG.osDarwin
+    nw.CONFIG.osDarwin = True
+    nwGUI = nw.main(
+        ["--testmode", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+    )
+    assert isinstance(nwGUI, DummyMain)
+    assert "Foundation" in caplog.messages[1]
+    nw.CONFIG.osDarwin = osDarwin
+
+    # Normal launch
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.__init__", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.setApplicationName", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.setApplicationVersion", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.setWindowIcon", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.setOrganizationDomain", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.exec_", lambda *args: 0)
+    with pytest.raises(SystemExit) as ex:
+        nw.main(["--config=%s" % tmpDir, "--data=%s" % tmpDir])
+
+    assert ex.value.code == 0
+
+    monkeypatch.undo()
+
+# END Test testBaseInit_Launch
+
+@pytest.mark.base
+def testBaseInit_Options(monkeypatch, tmpDir):
+    """Test command line options for logging level.
+    """
+    monkeypatch.setattr("nw.guimain.GuiMain", DummyMain)
+    monkeypatch.setattr(sys, "argv", [
+        "novelWriter.py", "--testmode", "--config=%s" % tmpDir, "--data=%s" % tmpDir
+    ])
+
+    # Defaults w/None Args
+    nwGUI = nw.main()
+    assert nw.logger.getEffectiveLevel() == logging.WARNING
+    assert nw.CONFIG.debugInfo is False
+    assert nw.CONFIG.showGUI is False
+    assert nwGUI.closeMain() == "closeMain"
+
+    # Defaults
+    nwGUI = nw.main(
+        ["--testmode", "--config=%s" % tmpDir, "--data=%s" % tmpDir, "--style=Fusion"]
+    )
+    assert nw.logger.getEffectiveLevel() == logging.WARNING
+    assert nw.CONFIG.debugInfo is False
+    assert nwGUI.closeMain() == "closeMain"
+
+    # Log Levels
+    nwGUI = nw.main(
+        ["--testmode", "--info", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+    )
+    assert nw.logger.getEffectiveLevel() == logging.INFO
+    assert nw.CONFIG.debugInfo is False
+    assert nwGUI.closeMain() == "closeMain"
+
+    nwGUI = nw.main(
+        ["--testmode", "--debug", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+    )
+    assert nw.logger.getEffectiveLevel() == logging.DEBUG
+    assert nw.CONFIG.debugInfo is True
+    assert nwGUI.closeMain() == "closeMain"
+
+    nwGUI = nw.main(
+        ["--testmode", "--verbose", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+    )
+    assert nw.logger.getEffectiveLevel() == 5
+    assert nw.CONFIG.debugInfo is True
+    assert nwGUI.closeMain() == "closeMain"
+
+    # Help and Version
+    with pytest.raises(SystemExit) as ex:
+        nwGUI = nw.main(
+            ["--testmode", "--help", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+        )
+    assert nwGUI.closeMain() == "closeMain"
+    assert ex.value.code == 0
+
+    with pytest.raises(SystemExit) as ex:
+        nwGUI = nw.main(
+            ["--testmode", "--version", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+        )
+    assert nwGUI.closeMain() == "closeMain"
+    assert ex.value.code == 0
+
+    # Invalid options
+    with pytest.raises(SystemExit) as ex:
+        nwGUI = nw.main(
+            ["--testmode", "--invalid", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+        )
+    assert nwGUI.closeMain() == "closeMain"
+    assert ex.value.code == 2
+
+    # Project Path
+    nwGUI = nw.main(
+        ["--testmode", "--config=%s" % tmpDir, "--data=%s" % tmpDir, "sample/"]
+    )
+    assert nw.CONFIG.cmdOpen == "sample/"
+    assert nwGUI.closeMain() == "closeMain"
+
+    monkeypatch.undo()
+
+# END Test testBaseInit_Options
+
+@pytest.mark.base
+def testBaseInit_Imports(caplog, monkeypatch, tmpDir):
+    """Check import error handling.
+    """
+    monkeypatch.setattr("nw.guimain.GuiMain", DummyMain)
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.__init__", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QApplication.exec_", lambda *args: 0)
+    monkeypatch.setattr("PyQt5.QtWidgets.QErrorMessage.__init__", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QErrorMessage.resize", lambda *args: None)
+    monkeypatch.setattr("PyQt5.QtWidgets.QErrorMessage.showMessage", lambda *args: None)
+    monkeypatch.setitem(sys.modules, "lxml", None)
+    monkeypatch.setattr("sys.hexversion", 0x0)
+    monkeypatch.setattr("nw.CONFIG.verQtValue", 50000)
+    monkeypatch.setattr("nw.CONFIG.verPyQtValue", 50000)
+
+    with pytest.raises(SystemExit) as ex:
+        _ = nw.main(
+            ["--testmode", "--config=%s" % tmpDir, "--data=%s" % tmpDir]
+        )
+
+    assert ex.value.code & 4 == 4   # Python version not satisfied
+    assert ex.value.code & 8 == 8   # Qt version not satisfied
+    assert ex.value.code & 16 == 16 # PyQt version not satisfied
+    assert ex.value.code & 32 == 32 # lxml package missing
+
+    assert "At least Python" in caplog.messages[0]
+    assert "At least Qt5" in caplog.messages[1]
+    assert "At least PyQt5" in caplog.messages[2]
+    assert "lxml" in caplog.messages[3]
+
+    monkeypatch.undo()
+
+# END Test testBaseInit_Imports
diff --git a/tests/test_config.py b/tests/test_config.py
deleted file mode 100644
index 94ff5d1c..00000000
--- a/tests/test_config.py
+++ /dev/null
@@ -1,165 +0,0 @@
-# -*- coding: utf-8 -*-
-"""novelWriter Config Class Tester
-"""
-
-import pytest
-import os
-
-from tools import cmpFiles
-
-@pytest.mark.core
-def testConfigCore(tmpConf, tmpDir, refDir):
-    refConf = os.path.join(refDir, "novelwriter.conf")
-    testConf = os.path.join(tmpConf.confPath, "novelwriter.conf")
-
-    assert tmpConf.confPath == tmpDir
-    assert tmpConf.saveConfig()
-    assert cmpFiles(testConf, refConf, [2, 9])
-    assert not tmpConf.confChanged
-
-    assert tmpConf.loadConfig()
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testConfigSetConfPath(tmpConf, tmpDir):
-    assert tmpConf.setConfPath(None)
-    assert not tmpConf.setConfPath(os.path.join("somewhere", "over", "the", "rainbow"))
-    assert tmpConf.setConfPath(os.path.join(tmpDir, "novelwriter.conf"))
-    assert tmpConf.confPath == tmpDir
-    assert tmpConf.confFile == "novelwriter.conf"
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testConfigSetDataPath(tmpConf, tmpDir):
-    assert tmpConf.setDataPath(None)
-    assert not tmpConf.setDataPath(os.path.join("somewhere", "over", "the", "rainbow"))
-    assert tmpConf.setDataPath(tmpDir)
-    assert tmpConf.dataPath == tmpDir
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testConfigSetWinSize(tmpConf, tmpDir, refDir):
-    refConf = os.path.join(refDir, "novelwriter.conf")
-    testConf = os.path.join(tmpConf.confPath, "novelwriter.conf")
-    tmpConf.guiScale = 1.0
-
-    assert tmpConf.confPath == tmpDir
-    assert tmpConf.setWinSize(1205, 655)
-    assert not tmpConf.confChanged
-    assert tmpConf.setWinSize(70, 70)
-    assert tmpConf.confChanged
-    assert tmpConf.setWinSize(1200, 650)
-    assert tmpConf.saveConfig()
-
-    assert cmpFiles(testConf, refConf, [2, 9])
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testConfigSetTreeColWidths(tmpConf, tmpDir, refDir):
-    refConf = os.path.join(refDir, "novelwriter.conf")
-    testConf = os.path.join(tmpConf.confPath, "novelwriter.conf")
-
-    assert tmpConf.confPath == tmpDir
-    tmpConf.guiScale = 1.0
-
-    assert tmpConf.setTreeColWidths([10, 20, 25])
-    assert tmpConf.treeColWidth == [10, 20, 25]
-    assert tmpConf.setTreeColWidths([200, 50, 30])
-
-    assert tmpConf.setProjColWidths([10, 20, 30])
-    assert tmpConf.projColWidth == [10, 20, 30]
-    assert tmpConf.setProjColWidths([200, 60, 140])
-
-    assert tmpConf.confChanged
-    assert tmpConf.saveConfig()
-
-    assert cmpFiles(testConf, refConf, [2, 9])
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testConfigSetPanePos(tmpConf, tmpDir, refDir):
-    refConf = os.path.join(refDir, "novelwriter.conf")
-    testConf = os.path.join(tmpConf.confPath, "novelwriter.conf")
-
-    assert tmpConf.confPath == tmpDir
-
-    tmpConf.guiScale = 2.0
-    assert tmpConf.setMainPanePos([200, 700])
-    assert tmpConf.mainPanePos == [100, 350]
-    assert tmpConf.getMainPanePos() == [200, 700]
-
-    assert tmpConf.setDocPanePos([300, 300])
-    assert tmpConf.docPanePos == [150, 150]
-    assert tmpConf.getDocPanePos() == [300, 300]
-
-    assert tmpConf.setViewPanePos([400, 250])
-    assert tmpConf.viewPanePos == [200, 125]
-    assert tmpConf.getViewPanePos() == [400, 250]
-
-    assert tmpConf.setOutlinePanePos([400, 250])
-    assert tmpConf.outlnPanePos == [200, 125]
-    assert tmpConf.getOutlinePanePos() == [400, 250]
-
-    tmpConf.guiScale = 1.0
-    assert tmpConf.setMainPanePos([300, 800])
-    assert tmpConf.setDocPanePos([400, 400])
-    assert tmpConf.setViewPanePos([500, 150])
-    assert tmpConf.setOutlinePanePos([500, 150])
-
-    assert tmpConf.confChanged
-    assert tmpConf.saveConfig()
-
-    assert cmpFiles(testConf, refConf, [2, 9])
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testConfigFlags(tmpConf, tmpDir, refDir):
-    refConf = os.path.join(refDir, "novelwriter.conf")
-    testConf = os.path.join(tmpConf.confPath, "novelwriter.conf")
-
-    assert tmpConf.confPath == tmpDir
-
-    assert not tmpConf.setShowRefPanel(False)
-    assert tmpConf.setShowRefPanel(True)
-
-    assert not tmpConf.setViewComments(False)
-    assert not tmpConf.viewComments
-    assert tmpConf.setViewComments(True)
-
-    assert not tmpConf.setViewSynopsis(False)
-    assert not tmpConf.viewSynopsis
-    assert tmpConf.setViewSynopsis(True)
-
-    assert tmpConf.confChanged
-    assert tmpConf.saveConfig()
-
-    assert cmpFiles(testConf, refConf, [2, 9])
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testTextSizes(tmpConf, tmpDir, refDir):
-    assert tmpConf.confPath == tmpDir
-
-    tmpConf.guiScale = 2.0
-    assert tmpConf.getTextWidth() == 1200
-    assert tmpConf.getTextMargin() == 80
-    assert tmpConf.getTabWidth() == 80
-    assert tmpConf.getFocusWidth() == 1600
-    tmpConf.guiScale = 1.0
-
-    assert not tmpConf.confChanged
-
-@pytest.mark.core
-def testConfigErrors(tmpConf):
-    nonPath = os.path.join("somewhere", "over", "the", "rainbow")
-    assert tmpConf.initConfig(nonPath, nonPath)
-    assert tmpConf.hasError
-    assert not tmpConf.loadConfig()
-    assert not tmpConf.saveConfig()
-    assert not tmpConf.loadRecentCache()
-    assert len(tmpConf.getErrData()) > 0
-
-@pytest.mark.core
-def testConfigInternals(tmpConf):
-    assert tmpConf._checkNone(None) is None
-    assert tmpConf._checkNone("None") is None
diff --git a/tests/test_core_project.py b/tests/test_core_project.py
index fe847983..3abefbbc 100644
--- a/tests/test_core_project.py
+++ b/tests/test_core_project.py
@@ -22,8 +22,8 @@ def testCoreProject_NewMinimal(fncDir, outDir, refDir, tmpDir, dummyGUI):
     default setting, creating a Minimal project.
     """
     projFile = os.path.join(fncDir, "nwProject.nwx")
-    testFile = os.path.join(outDir, "coreProject_1_nwProject.nwx")
-    compFile = os.path.join(refDir, "coreProject_1_nwProject.nwx")
+    testFile = os.path.join(outDir, "coreProject_NewMinimal_nwProject.nwx")
+    compFile = os.path.join(refDir, "coreProject_NewMinimal_nwProject.nwx")
 
     theProject = NWProject(dummyGUI)
     theProject.projTree.setSeed(42)
@@ -70,8 +70,8 @@ def testCoreProject_NewCustomA(fncDir, outDir, refDir, dummyGUI):
     Custom type with chapters and scenes.
     """
     projFile = os.path.join(fncDir, "nwProject.nwx")
-    testFile = os.path.join(outDir, "coreProject_2_nwProject.nwx")
-    compFile = os.path.join(refDir, "coreProject_2_nwProject.nwx")
+    testFile = os.path.join(outDir, "coreProject_NewCustomA_nwProject.nwx")
+    compFile = os.path.join(refDir, "coreProject_NewCustomA_nwProject.nwx")
 
     projData = {
         "projName": "Test Custom",
@@ -111,8 +111,8 @@ def testCoreProject_NewCustomB(fncDir, outDir, refDir, dummyGUI):
     Custom type without chapters, but with scenes.
     """
     projFile = os.path.join(fncDir, "nwProject.nwx")
-    testFile = os.path.join(outDir, "coreProject_3_nwProject.nwx")
-    compFile = os.path.join(refDir, "coreProject_3_nwProject.nwx")
+    testFile = os.path.join(outDir, "coreProject_NewCustomB_nwProject.nwx")
+    compFile = os.path.join(refDir, "coreProject_NewCustomB_nwProject.nwx")
 
     projData = {
         "projName": "Test Custom",
@@ -238,8 +238,8 @@ def testCoreProject_NewRoot(fncDir, outDir, refDir, dummyGUI):
     """Check that new root folders can be added to the project.
     """
     projFile = os.path.join(fncDir, "nwProject.nwx")
-    testFile = os.path.join(outDir, "coreProject_4_nwProject.nwx")
-    compFile = os.path.join(refDir, "coreProject_4_nwProject.nwx")
+    testFile = os.path.join(outDir, "coreProject_NewRoot_nwProject.nwx")
+    compFile = os.path.join(refDir, "coreProject_NewRoot_nwProject.nwx")
 
     theProject = NWProject(dummyGUI)
     theProject.projTree.setSeed(42)
@@ -274,8 +274,8 @@ def testCoreProject_NewFile(fncDir, outDir, refDir, dummyGUI):
     """Check that new files can be added to the project.
     """
     projFile = os.path.join(fncDir, "nwProject.nwx")
-    testFile = os.path.join(outDir, "coreProject_5_nwProject.nwx")
-    compFile = os.path.join(refDir, "coreProject_5_nwProject.nwx")
+    testFile = os.path.join(outDir, "coreProject_NewFile_nwProject.nwx")
+    compFile = os.path.join(refDir, "coreProject_NewFile_nwProject.nwx")
 
     theProject = NWProject(dummyGUI)
     theProject.projTree.setSeed(42)
diff --git a/tests/test_error.py b/tests/test_error.py
deleted file mode 100644
index 192fb6cb..00000000
--- a/tests/test_error.py
+++ /dev/null
@@ -1,44 +0,0 @@
-# -*- coding: utf-8 -*-
-"""novelWriter Error Tester
-"""
-
-import nw
-import pytest
-
-from PyQt5.QtWidgets import qApp
-
-from nw.error import NWErrorMessage, exceptionHandler
-
-@pytest.mark.error
-def testErrorDialog(qtbot, fncDir, tmpDir):
-    qApp.closeAllWindows()
-    nwGUI = nw.main(["--testmode", "--config=%s" % fncDir, "--data=%s" % tmpDir])
-    qtbot.addWidget(nwGUI)
-    nwGUI.show()
-    qtbot.waitForWindowShown(nwGUI)
-
-    nwErr = NWErrorMessage(nwGUI)
-    qtbot.addWidget(nwErr)
-    nwErr.show()
-
-    # Invalid Error
-    nwErr.setMessage(Exception, "Faulty Error", 123)
-    assert nwErr.msgBody.toPlainText() == "Failed to generate error report ..."
-
-    # Valid Error
-    nwErr.setMessage(Exception, "First Error", None)
-    theMessage = nwErr.msgBody.toPlainText()
-    assert theMessage
-    assert "First Error" in theMessage
-    assert "Exception" in theMessage
-    nwErr._doClose()
-    nwErr.close()
-
-    theMessage = exceptionHandler(Exception, "Second Error", None, testMode=True)
-    assert theMessage
-    assert "Second Error" in theMessage
-    assert "Exception" in theMessage
-
-    nwGUI.closeMain()
-
-    # qtbot.stopForInteraction()
diff --git a/tests/test_gui_main.py b/tests/test_gui_main.py
index a10c0582..b56c525b 100644
--- a/tests/test_gui_main.py
+++ b/tests/test_gui_main.py
@@ -4,9 +4,7 @@
 
 import nw
 import pytest
-import logging
 import os
-import sys
 
 from shutil import copyfile
 from tools import cmpFiles
@@ -26,82 +24,6 @@ keyDelay = 2
 typeDelay = 1
 stepDelay = 20
 
-@pytest.mark.gui
-def testLaunch(qtbot, monkeypatch, fncDir, tmpDir):
-
-    # Defaults
-    nwGUI = nw.main(
-        ["--testmode", "--config=%s" % fncDir, "--data=%s" % tmpDir, "--style=Fusion"]
-    )
-    assert nw.logger.getEffectiveLevel() == logging.WARNING
-    nwGUI.closeMain()
-    nwGUI.close()
-
-    # Log Levels
-    nwGUI = nw.main(
-        ["--testmode", "--info", "--config=%s" % fncDir, "--data=%s" % tmpDir]
-    )
-    assert nw.logger.getEffectiveLevel() == logging.INFO
-    nwGUI.closeMain()
-    nwGUI.close()
-
-    nwGUI = nw.main(
-        ["--testmode", "--debug", "--config=%s" % fncDir, "--data=%s" % tmpDir]
-    )
-    assert nw.logger.getEffectiveLevel() == logging.DEBUG
-    nwGUI.closeMain()
-    nwGUI.close()
-
-    nwGUI = nw.main(
-        ["--testmode", "--verbose", "--config=%s" % fncDir, "--data=%s" % tmpDir]
-    )
-    assert nw.logger.getEffectiveLevel() == 5
-    nwGUI.closeMain()
-    nwGUI.close()
-
-    # Help and Version
-    with pytest.raises(SystemExit) as ex:
-        nwGUI = nw.main(
-            ["--testmode", "--help", "--config=%s" % fncDir, "--data=%s" % tmpDir]
-        )
-    nwGUI.closeMain()
-    nwGUI.close()
-    assert ex.value.code == 0
-
-    with pytest.raises(SystemExit) as ex:
-        nwGUI = nw.main(
-            ["--testmode", "--version", "--config=%s" % fncDir, "--data=%s" % tmpDir]
-        )
-    nwGUI.closeMain()
-    nwGUI.close()
-    assert ex.value.code == 0
-
-    # Invalid options
-    with pytest.raises(SystemExit) as ex:
-        nwGUI = nw.main(
-            ["--testmode", "--invalid", "--config=%s" % fncDir, "--data=%s" % tmpDir]
-        )
-    nwGUI.closeMain()
-    nwGUI.close()
-    assert ex.value.code == 2
-
-    # Simulate import error
-    monkeypatch.setitem(sys.modules, "lxml", None)
-    monkeypatch.setattr("sys.hexversion", 0x0)
-    monkeypatch.setattr("nw.CONFIG.verQtValue", 50000)
-    monkeypatch.setattr("nw.CONFIG.verPyQtValue", 50000)
-    with pytest.raises(SystemExit) as ex:
-        nwGUI = nw.main(
-            ["--testmode", "--config=%s" % fncDir, "--data=%s" % tmpDir]
-        )
-    nwGUI.closeMain()
-    nwGUI.close()
-    assert ex.value.code & 4 == 4   # Python version not satisfied
-    assert ex.value.code & 8 == 8   # Qt version not satisfied
-    assert ex.value.code & 16 == 16 # PyQt version not satisfied
-    assert ex.value.code & 32 == 32 # lxml package missing
-    monkeypatch.undo()
-
 @pytest.mark.gui
 def testDocEditor(qtbot, yesToAll, fncDir, nwTempGUI, refDir, tmpDir):