class_docstr: Negative test cases of alias interface operations
class_docstr_tok: ["Negative","test","cases","of","alias","interface","operations"]
docstr: target: test collection altering to alias which is not exist
  method: 
          1.create a collection with alias
          2.collection alters to an alias name which is not exist
  expected: 
          in step 2, alter alias with a not exist name is not allowed
docstr_tok: ["target",":","test","collection","altering","to","alias","which","is","not","exist","method",":","1.create","a","collection","with","alias","2.collection","alters","to","an","alias","name","which","is","not","exist","expected",":","in","step","2",",","alter","alias","with","a","not","exist","name","is","not","allowed"]
code: def test_alias_alter_not_exist_alias(self):
      """
      target: test collection altering to alias which is not exist
      method:
              1.create a collection with alias
              2.collection alters to an alias name which is not exist
      expected:
              in step 2, alter alias with a not exist name is not allowed
      """
      self._connect()
      c_name = cf.gen_unique_str("collection")
      collection_w = self.init_collection_wrap(
          name=c_name,
          schema=default_schema,
          check_task=CheckTasks.check_collection_property,
          check_items={exp_name: c_name, exp_schema: default_schema},
      )
      alias_name = cf.gen_unique_str(prefix)
      self.utility_wrap.create_alias(collection_w.name, alias_name)
      # collection_w.create_alias(alias_name)
  
      alias_not_exist_name = cf.gen_unique_str(prefix)
      error = {
          ct.err_code: 1600,
          ct.err_msg: "Alter alias failed: alias does not exist",
      }
      self.utility_wrap.alter_alias(
          collection_w.name,
          alias_not_exist_name,
          check_task=CheckTasks.err_res,
          check_items=error,
      )
  
imports: import pytest
  import random
  from base.client_base import TestcaseBase
  from utils.util_log import test_log
  from common import common_func
  from common import common_type
  from common.common_type import CaseLabel, CheckTasks
label_desc: Use image node_id 2 for calling the TestAliasOperationInvalid obj's underlying member method code with example usage: obj.test_alias_alter_not_exist_alias() without return types