The mapping expected in EmbeddableMappingTest#testEmbeddableCollection() seems wrong to me. Instead of
... "anEmbeddedCollection" : [ { "item" : "item[1]", "embeddedString" : "string[1][0]", "embeddedInteger" : 10 } { "item" : "item[0]", "anotherItem" : "secondItem[0]" } ]
it should be:
"anEmbeddedCollection": [ { "anotherItem": "secondItem[0]", "item": "item[0]" }, { "embedded": { "embeddedInteger": 10, "embeddedString": "string[1][0]" }, "item": "item[1]" } ],
I am not sure yet why, but when updating ot ORM 5 (OGM-770) the mapping is done in the second form which looks correct to me instead of the current one.