Unit test fixes (#10019)

* Add --keepdb option for unit test

* Reduce server launch overhead

- isGeneratingSchema was EXPENSIVE
- Running a single unit test reduced from 30s to 3s

* Option to disable check

tasks.py

@@ -1212,33 +1212,29 @@ def test_translations(c):
 
 @task(
     help={
+        'check': 'Run sanity check on the django install (default = False)',
         'disable_pty': 'Disable PTY',
         'runtest': 'Specify which tests to run, in format <module>.<file>.<class>.<method>',
         'migrations': 'Run migration unit tests',
         'report': 'Display a report of slow tests',
         'coverage': 'Run code coverage analysis (requires coverage package)',
+        'translations': 'Compile translations before running tests',
+        'keepdb': 'Keep the test database after running tests (default = False)',
     }
 )
 def test(
     c,
+    check=False,
     disable_pty=False,
     runtest='',
     migrations=False,
     report=False,
     coverage=False,
     translations=False,
+    keepdb=False,
 ):
     """Run unit-tests for InvenTree codebase.
 
-    Args:
-        c: Command line context.
-        disable_pty (bool): Disable PTY (default = False)
-        runtest (str): Specify which tests to run, in format <module>.<file>.<class>.<method> (default = '')
-        migrations (bool): Run migration unit tests (default = False)
-        report (bool): Display a report of slow tests (default = False)
-        coverage (bool): Run code coverage analysis (requires coverage package) (default = False)
-        translations (bool): Compile translations before running tests (default = False)
-
     To run only certain test, use the argument --runtest.
     This can filter all the way down to:
         <module>.<file>.<class>.<method>
@@ -1248,7 +1244,8 @@ def test(
     will run tests in the company/test_api.py file.
     """
     # Run sanity check on the django install
-    manage(c, 'check')
+    if check:
+        manage(c, 'check')
 
     if translations:
         try:
@@ -1272,6 +1269,9 @@ def test(
     if report:
         cmd += ' --slowreport'
 
+    if keepdb:
+        cmd += ' --keepdb'
+
     if migrations:
         cmd += ' --tag migration_test'
     else: