fix: multi value header handling #1888

sdelamo · 2023-09-20T10:41:30Z

Multiple message-header fields with the same field-name MAY be
present in a message if and only if the entire field-value for that
header field is defined as a comma-separated list [i.e., #(values)].
It MUST be possible to combine the multiple header fields into one
"field-name: field-value" pair, without changing the semantics of the
message, by appending each subsequent field-value to the first, each
separated by a comma.

But there are headers which have a , without using it to designate a multi-value. E.g. Date. Thus, a mess 🤷🏼‍♂️

Close #1861

sdelamo · 2023-09-20T10:41:39Z

ping @driverpt

sdelamo · 2023-09-20T10:42:33Z

...on-aws-api-proxy/src/test/groovy/io/micronaut/function/aws/proxy/MapCollapseUtilsSpec.groovy

+import spock.lang.Specification
+
+@MicronautTest
+class MapCollapseUtilsSpec extends Specification {


The examples Foo and Key in this test are taken directly from the AWS Lambda Console. I did request and logged them to see how they are represented in the Lambda Event Objects.

timyates · 2023-09-20T12:52:01Z

function-aws-api-proxy/src/main/java/io/micronaut/function/aws/proxy/MapCollapseUtils.java

@@ -31,6 +35,8 @@
 @Internal
 public final class MapCollapseUtils {

+    private static final List<String> HEADERS_ALLOWING_COMMAS = Arrays.asList(HttpHeaders.DATE, HttpHeaders.USER_AGENT);
