move test section to an independent document.

README.md

@@ -116,6 +116,8 @@ TDengine provides abundant developing tools for users to develop on TDengine. Fo
 - [Node.js](https://www.taosdata.com/en/documentation/connector/#Node.js-Connector)
 
 # How to run the test cases and how to add a new test case?
+  TDengine's test framework and all test cases are fully open source.
+  Please refer to [this document](https://www.github.com/taosdata/TDengine/tests/How-To-Run-Test-And-How-To-Add-New-Test-Case.md) for how to run test and develop new test case.
 
 ### Prepare development environment
 

tests/How-To-Run-Test-And-How-To-Add-New-Test-Case.md

+### How to add a new test case
+
+**1. TSIM test cases:**
+
+TSIM test cases are the testing framework has been used internally. Now it still be used to run the test cases we develop in the past as a legacy system. We are turning to use Python to develop new test case and are abandoning TSIM gradually.
+
+**2. Python test cases:**
+
+**2.1 Please refer to \<TDengine\>/tests/pytest/insert/basic.py to add a new
+test case.** The new test case must implement 3 functions, where self.init()
+and self.stop() simply copy the contents of insert/basic.py and the test
+logic is implemented in self.run(). You can refer to the code in the util
+directory for more information.
+
+**2.2 Edit smoketest.sh to add the path and filename of the new test case**
+
+Note: The Python test framework may continue to be improved in the future,
+hopefully, to provide more functionality and ease of writing test cases. The
+method of writing the test case above does not exclude that it will also be
+affected.
+
+**2.3 What test.py does in detail:**
+
+test.py is the entry program for test case execution and monitoring.
+
+test.py has the following functions.
+
+\-f --file, Specifies the test case file name to be executed
+-p --path, Specifies deployment path
+
+\-m --master, Specifies the master server IP for cluster deployment 
+-c--cluster, test cluster function
+-s--stop, terminates all running nodes
+
+\-g--valgrind, load valgrind for memory leak detection test
+
+\-h--help, display help
+
+**2.4 What util/log.py does in detail:**
+
+log.py is quite simple, the main thing is that you can print the output in
+different colors as needed. The success() should be called for successful
+test case execution and the success() will print green text. The exit() will
+print red text and exit the program, exit() should be called for test
+failure.
+
+**util/log.py**
+
+...
+
+    def info(self, info):
+
+        printf("%s %s" % (datetime.datetime.now(), info))
+
+ 
+
+    def sleep(self, sec):
+
+        printf("%s sleep %d seconds" % (datetime.datetime.now(), sec))
+
+        time.sleep(sec)
+
+ 
+
+    def debug(self, err):
+
+        printf("\\033[1;36m%s %s\\033[0m" % (datetime.datetime.now(), err))
+
+ 
+
+    def success(self, info):
+
+        printf("\\033[1;32m%s %s\\033[0m" % (datetime.datetime.now(), info))
+
+ 
+
+    def notice(self, err):
+
+        printf("\\033[1;33m%s %s\\033[0m" % (datetime.datetime.now(), err))
+
+ 
+
+    def exit(self, err):
+
+        printf("\\033[1;31m%s %s\\033[0m" % (datetime.datetime.now(), err))
+
+        sys.exit(1)
+
+ 
+
+    def printNoPrefix(self, info):
+
+        printf("\\033[1;36m%s\\033[0m" % (info)
+
+...
+
+**2.5 What util/sql.py does in detail:**
+
+SQL.py is mainly used to execute SQL statements to manipulate the database,
+and the code is extracted and commented as follows:
+
+**util/sql.py**
+
+\# prepare() is mainly used to set up the environment for testing table and
+data, and to set up the database db for testing. do not call prepare() if you
+need to test the database operation command.
+
+def prepare(self):
+
+tdLog.info("prepare database:db")
+
+self.cursor.execute('reset query cache')
+
+self.cursor.execute('drop database if exists db')
+
+self.cursor.execute('create database db')
+
+self.cursor.execute('use db')
+
+...
+
+\# query() is mainly used to execute select statements for normal syntax input
+
+def query(self, sql):
+
+...
+
+\# error() is mainly used to execute the select statement with the wrong syntax
+input, the error will be caught as a reasonable behavior, if not caught it will
+prove that the test failed
+
+def error()
+
+...
+
+\# checkRows() is used to check the number of returned lines after calling
+query(select ...) after calling the query(select ...) to check the number of
+rows of returned results.
+
+def checkRows(self, expectRows):
+
+...
+
+\# checkData() is used to check the returned result data after calling
+query(select ...) after the query(select ...) is called, failure to meet
+expectation is
+
+def checkData(self, row, col, data):
+
+...
+
+\# getData() returns the result data after calling query(select ...) to return
+the resulting data after calling query(select ...)
+
+def getData(self, row, col):
+
+...
+
+\# execute() used to execute sql and return the number of affected rows
+
+def execute(self, sql):
+
+...
+
+\# executeTimes() Multiple executions of the same sql statement
+
+def executeTimes(self, sql, times):
+
+...
+
+\# CheckAffectedRows() Check if the number of affected rows is as expected
+
+def checkAffectedRows(self, expectAffectedRows):
+
+...
+
+>   Note: Both Python2 and Python3 are currently supported by the Python test
+>   case. Since Python2 is no longer officially supported by January 1, 2020, it
+>   is recommended that subsequent test case development be guaranteed to run
+>   correctly on Python3. For Python2, please consider being compatible if
+>   appropriate without additional
+>   burden. <https://nakedsecurity.sophos.com/2020/01/03/python-is-dead-long-live-python/> 
+