When I hit the query:
db.sample.find({ $text:

})

I get only one result:

/* 1 */
{
    "_id" : ObjectId("5ad609baac1a8b644180936b"),
    "content" : "coffee shop..."
}

Here is the data set:

/* 1 */
{
    "_id" : ObjectId("5ad609a2ac1a8b644180936a"),
    "content" : "Coffee and cakes..."
}

/* 2 */
{
    "_id" : ObjectId("5ad609baac1a8b644180936b"),
    "content" : "coffee shop..."
}

Text index was already created for content field.

As per the mongo docs here:
https://docs.mongodb.com/manual/text-search/

It says it returns all documents containing “coffee shop” OR “cakes”. So it should return both documents. It isnt happening here.