fix(testing docs): fix testing docs typos and syntax

docs/developer-guide/unit-testing.md

@@ -58,7 +58,7 @@ For the AWS provider we have ways to test a Prowler check based on the following
     - Service test with `@mock_<service>` and `mock_make_api_call`
     - Checks tests with `@mock_<service>` and `mock_make_api_call`
 
-In the following section we are going to explain all of the above scenarios with examples based on if the [Moto](https://github.com/getmoto/moto) library covers the AWS API calls made by the service. You can check the covered API calls [here](https://github.com/getmoto/moto/blob/master/IMPLEMENTATION_COVERAGE.md).
+In the following section we are going to explain all of the above scenarios with examples. The main difference between those scenarios comes from if the [Moto](https://github.com/getmoto/moto) library covers the AWS API calls made by the service. You can check the covered API calls [here](https://github.com/getmoto/moto/blob/master/IMPLEMENTATION_COVERAGE.md).
 
 An important point for the AWS testing is that in each check we MUST have a unique `audit_info` which is the key object during the AWS execution to isolate the test execution.
 
@@ -112,7 +112,7 @@ This section is going to be divided based on the API coverage of the [Moto](http
 
 #### API calls covered
 
-If the [Moto](https://github.com/getmoto/moto) library covers the API calls we want to test we can use the `@mock_<service>` decorator which will mocked out all the API calls made to AWS keeping the state within the code decorated, in this case the test function.
+If the [Moto](https://github.com/getmoto/moto) library covers the API calls we want to test, we can use the `@mock_<service>` decorator. This will mocked out all the API calls made to AWS keeping the state within the code decorated, in this case the test function.
 
 ```python
 # We need to import the unittest.mock to allow us to patch some objects
@@ -193,7 +193,7 @@ class Test_iam_password_policy_uppercase:
 
 #### API calls not covered
 
-If the IAM service for the check's we want to test is not covered by Moto we have to inject the objects in the service client using [MagicMock](https://docs.python.org/3/library/unittest.mock.html#unittest.mock.MagicMock) because we cannot instantiate the service since it will make real calls to the AWS APIs.
+If the IAM service for the check's we want to test is not covered by Moto, we have to inject the objects in the service client using [MagicMock](https://docs.python.org/3/library/unittest.mock.html#unittest.mock.MagicMock). As we have pointed above, we cannot instantiate the service since it will make real calls to the AWS APIs.
 
 > The following example uses the IAM GetAccountPasswordPolicy which is covered by Moto but this is only for demonstration purposes.
 
@@ -236,7 +236,7 @@ class Test_iam_password_policy_uppercase:
     # between checks
     current_audit_info = self.set_mocked_audit_info()
 
-    # In this scenario we have to mock also the IAM service and the iam_client from the check to enforce that the iam_client used is the one created within this check because patch != import, and if you execute tests in parallel some objects can be already initialised hence the check won't be isolated.
+    # In this scenario we have to mock also the IAM service and the iam_client from the check to enforce    # that the iam_client used is the one created within this check because patch != import, and if you     # execute tests in parallel some objects can be already initialised hence the check won't be isolated.
     # In this case we don't use the Moto decorator, we use the mocked IAM client for both objects
     with mock.patch(
         "prowler.providers.aws.services.iam.iam_service.IAM",
@@ -269,6 +269,8 @@ class Test_iam_password_policy_uppercase:
         assert result[0].region == AWS_REGION
 ```
 
+As it can be seen in the above scenarios, the check execution should always be into the context of mocked/patched objects. This way we ensure it reviews only the objects created under the scope the test.
+
 #### API calls partially covered
 
 If the API calls we want to use in the service are partially covered by the Moto decorator we have to create our own mocked API calls to use it in combination.
@@ -363,7 +365,7 @@ from prowler.providers.<provider>.services.<service>.<service>_service import <S
 <service>_client = <SERVICE>(audit_info)
 ```
 
-Due to the above import path it's not the same to patch the following objects because if you run a bunch of tests, either in parallel or not, some clients can be already instantiated by another check, hence your test exection will be using another test's service instance:
+Due to the above import path it's not the same to patch the following objects because if you run a bunch of tests, either in parallel or not, some clients can be already instantiated by another check, hence your test execution will be using another test's service instance:
 
 - `<service>_client` imported at `<check>.py`
 - `<service>_client` initialised at `<service>_client.py`
@@ -406,7 +408,7 @@ with mock.patch(
     new=audit_info,
 ), mock.patch(
     "prowler.providers.aws.services.<service>.<SERVICE>",
-    return_value=<SERVICE>(audit_info),
+    new=<SERVICE>(audit_info),
 ) as service_client, mock.patch(
     "prowler.providers.aws.services.<service>.<service>_client.<service>_client",
     new=service_client,