Adding Lex v2 event and response

[Sordie]

Issue #, if available:
#242

Description of changes:
Adding both Lex version 2 event and response as defined here: https://docs.aws.amazon.com/lexv2/latest/dg/lambda.html

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[msailes]

Could you add a test into the serialization module?

https://github.com/aws/aws-lambda-java-libs/blob/master/aws-lambda-java-serialization/src/test/java/com/amazonaws/services/lambda/runtime/serialization/events/LambdaEventSerializersTest.java

[Sordie]

Thanks for the quick feedback, I have added the book trip example event as test case. However, for now there is a mismatch. The Json contains

"slots": {
    "ReturnDate": null,
    "PickUpDate": null,
    "DriverAge": null,
    "CarType": null,
    "PickUpCity": null
}

while the result is

"slots": {},

I'm unsure if that's the primary reason for the failing test and how to best fix this. Additionally, "nluConfidence": 1 gets parsed as "nluConfidence": 1.0 as expected but might still result in errors while testing.

As the test Json right now does not contain all possible fields, I will see if I can capture them in the next few days.

Finally, after having merge the current master the LambdaEventSerializersTests appear to have been skipped, at least on my end.

[msailes]

is this a typo?

[msailes]

Hi @Sordie,

Could this PR be change to target the V4 branch? You can use the Jackson annotations to handle the capitalisation.

[msailes]

Could you check the tests?

[Sordie]

Hi @msailes,
I have added an additional Lex event that includes the optional parts for both sentiment and Kendra. However, I’m still struggling with the tests. As already mentioned above the tests currently fail, because the slots map is empty after the deserialization and subsequent serialization. At this point I haven’t found an easy way to fix this. Could you share your opinion on how to best proceed? Maybe you already have an idea how to solve this issue?

[msailes]

The testLexV2Event seems to be failing because the test input lex_v2_event.json contains a Map with null values. In the JacksonPojoSerializer class we set mapper.setSerializationInclusion(Include.NON_NULL); which excludes null values.

          "intent": {
              "slots": {
                  "ReturnDate": null,
                  "PickUpDate": null,
                  "DriverAge": null,
                  "CarType": null,
                  "PickUpCity": null
              },

I don't know if this is bad data or possible? @Sordie do you know?

[msailes]

Same for the testLexV2KendraSentimentEvent test.

[Sordie]

@msailes thanks for pointing out where the configuration to exclude null values is, as I had not seen it before.
Regarding the possibility of bad data in the test events, both event json files contain data taken directly from the input of a TypeScript Lambda that was attached to a Lex bot. I only replaced some unique identifiers with example strings. Therefore, I would say that this data is representative of the actual input a lambda will receive from the Lex service.

[msailes]

@Sordie thank you.

I think the tests you've added should be slightly changed then to show this behavior. The actual will be different to the json from the test file because maps which include items will null values are excluded.

@andclt, @smirnoal I'm not sure how you want this implementing, maybe two files would be a suitable way?

@andclt, @smirnoal I found this a hard problem to track down since there was no specific JSON knowledge in the testing lib. I would suggest with move to JSONassert either in this PR or another seperate one. This library gave much better error messages and I was able to spot the problem straight away.

[msailes]

@Sordie, can you update your branch to pull in the new JSONAssert changes.

Then I suggest you change your tests to assert that given a json document with a map of items with null values, these are removed during serialisation.

#344

[andclt]

First of all thanks for contributing @Sordie!

I agree with @msailes' suggestion. However, if you want to keep those null values after the serialization, I think you can achieve it adding the @JsonInclude annotation (https://fasterxml.github.io/jackson-annotations/javadoc/2.9/com/fasterxml/jackson/annotation/JsonInclude.html) at the field level. This will override the global custom serialization behaviour that is currently excluding null values.

[andclt]

Hi @Sordie,

As I said in a previous message on this thread, I think we should use the @JsonInclude annotation to override our current Jackson configuration (that's excluding null values) instead of using a different json file to compare the lex event v2 serialization.

I was able to test successfully the following implementation, could you please take a look at it?

private Map<String, Slot> slots;

@JsonInclude(value=JsonInclude.Include.NON_NULL, content=JsonInclude.Include.ALWAYS)
public Map<String, Slot> getSlots() {
    return this.slots;
}

@JsonInclude(value=JsonInclude.Include.NON_NULL, content=JsonInclude.Include.ALWAYS)
public void setSlots(Map<String, Slot> slots) {
    this.slots = slots;
}

[Sordie]

Hi @andclt, thanks for providing a code snippet. I will add your suggestion next week once I have a computer in front of me again.

[Sordie]

Hi @andclt, I have applied your suggestion and removed the now unused json files.

[andclt]

Hi @Sordie, thank you! Approved!