test: add unit tests for connectors validation functions of microcks_client.go

[patilpratik1905]

Description

Problem :

The pkg/connectors package had no test coverage for critical validation functions:

• ensureValidOperationsList
• ensureValidOperationsHeaders
• ensureValieOAuth2Context

These functions act as gatekeepers for validating JSON inputs before sending data to Microcks APIs. Without tests, malformed inputs could go undetected.

Solution :

Added 33 table-driven unit tests in:
New file: pkg/connectors/microcks_client_test.go

TestEnsureValidOperationsList (10 tests)

• Valid array with single and multiple entries
• Valid empty array
• Invalid: plain string, object, malformed JSON, missing bracket
• Invalid: array of numbers instead of strings
• Valid: special characters in operation names

TestEnsureValidOperationsHeaders (10 tests)

• Valid: single operation, multiple operations, multiple headers per operation
• Valid: empty map, empty header array per operation
• Invalid: malformed JSON, plain string, array instead of map
• Invalid: wrong value type (string instead of array), missing closing brace

TestEnsureValidOAuth2Context (13 tests)

• Valid: all three supported grant types (PASSWORD, CLIENT_CREDENTIALS, REFRESH_TOKEN)
• Valid: optional scopes field, minimal required fields
• Invalid: unsupported grant type, empty grant type, missing grant type
• Invalid: wrong casing on grant type (case-sensitive validation)
• Invalid: malformed JSON, plain string, empty string, array instead of object

Related issue(s)

NA