Fix a number of flaky tests

[mohasarc]

Based on your comment and the follow-up comment to change src/main, I'm opening this PR to address some tests by changing src/main. If you prefer to address this differently, please let me know so I can revise the PR.

According to the test results obtained using the NonDex tool, I have confirmed several flaky tests; these tests can pass or fail non-deterministically. The main reason for this flakiness is the order of the fields returned by the getDeclatedFields() method. This method has been used internally by Jackson library's ObjectMapper; therefore, the default output of ObjectMapper is not deterministic (documentation).

typescript-generator/typescript-generator-core/src/main/java/cz/habarta/typescript/generator/parser/Jackson2Parser.java

Line 116 in 107eb2f

private final ObjectMapper objectMapper = new ObjectMapper();

To solve this, I have configured ObjectMapper to return the fields in alphabetical order.

Finally, I have changed some of the tests into an alphabetical order to fit the changes to the main code. here is a list of all the flaky tests that were fixed:

• cz.habarta.typescript.generator.EnumTest.testObjectEnum
• cz.habarta.typescript.generator.GenericsTest.testAdvancedGenerics
• cz.habarta.typescript.generator.JsonUnwrappedTest.test
• cz.habarta.typescript.generator.JsonUnwrappedTest.testPrivateField
• cz.habarta.typescript.generator.ClassesTest.testUnsortedConstructor
• cz.habarta.typescript.generator.Jackson2ParserTest.test
• cz.habarta.typescript.generator.OptionalTest.test
• cz.habarta.typescript.generator.OptionalTest.testDeclarationNullableAndUndefinableType
• cz.habarta.typescript.generator.OptionalTest.testDeclarationNullableType
• cz.habarta.typescript.generator.OptionalTest.testDeclarationQuestionMark
• cz.habarta.typescript.generator.OptionalTest.testDeclarationQuestionMarkAndNullableType
• cz.habarta.typescript.generator.OptionalTest.testDeclarationUndefinableType
• cz.habarta.typescript.generator.TaggedUnionsTest.testTaggedUnions
• cz.habarta.typescript.generator.TaggedUnionsTest.testTaggedUnionsDisabled
• cz.habarta.typescript.generator.TaggedUnionsTest.testTaggedUnionsWithExistingProperty
• cz.habarta.typescript.generator.TaggedUnionsTest.testTaggedUnionsWithInterfaces
• cz.habarta.typescript.generator.JavadocTest.testJavadoc
• cz.habarta.typescript.generator.TaggedUnionsTest.testIntermediateUnions
• cz.habarta.typescript.generator.JaxrsApplicationTest.testEnumQueryParam