Added tests for environments handler

[Freedisch]

Proposed changes:

Added testcases for environments handler https://github.com/litmuschaos/litmus/blob/master/chaoscenter/graphql/server/pkg/environment/handler/handler.go

this follows the previous PR #4159

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• Bugfix (non-breaking change which fixes an issue)
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Special notes for your reviewer:

[S-ayanide]

LGTM

[namkyu1999]

Hey @Freedisch , proposed changes looks good to me. Just a small request,

You defined a struct called MockEnvironmentOperator, but you didn't use it. In all your test code, instead of using operator := &environments.Operator{} Please use mock operator.

[Freedisch]

@namkyu1999, I have completed the necessary changes

[namkyu1999]

Take a look at my comments, please!

[namkyu1999]

How about mocking the Mongo Operator instead of mocking the Environment Operator? This allows you to write test cases that are flexible to future changes in the Environment Operator. How do you think?

import (
  dbMocks "github.com/litmuschaos/litmus/chaoscenter/graphql/server/pkg/database/mongodb/mocks"
  dbOperationsEnvironment "github.com/litmuschaos/litmus/chaoscenter/graphql/server/pkg/database/mongodb/environments"
)

mongodbMockOperator := new(dbMocks.MongoOperator)
environmentOperator := dbOperationsEnvironment.NewEnvironmentOperator(mongodbMockOperator)

reference: https://github.com/litmuschaos/litmus/blob/master/chaoscenter/graphql/server/pkg/chaos_experiment_run/service_test.go

[Freedisch]

I think I could stick with Environment Operator since I already updated the handler to consider an environment Mockoperator

[namkyu1999]

okay, thanks

[Saranya-jena]

@namkyu1999 Could review this PR again?

[namkyu1999]

IMO, we don't need this code if we adopt below code

import (
  dbMocks "github.com/litmuschaos/litmus/chaoscenter/graphql/server/pkg/database/mongodb/mocks"
  dbOperationsEnvironment "github.com/litmuschaos/litmus/chaoscenter/graphql/server/pkg/database/mongodb/environments"
)

mongodbMockOperator := new(dbMocks.MongoOperator)
environmentOperator := dbOperationsEnvironment.NewEnvironmentOperator(mongodbMockOperator)

we don't also need MockEnvironmentOperator struct and relevant functions in chaoscenter/graphql/server/pkg/environment/handler/handler_test.go if we adopt the above.

I think reducing unnecessary code is a great way to make open source understandable to many people.

How do you think @Saranya-jena @gdsoumya @Freedisch ?

[Freedisch]

Make sense. I updated the code to reflect it

[namkyu1999]

LGTM 🚀 @Freedisch