Meteor: meteor-collectionapi PUT overwrites the entire object instead of just updating the field I want - api

Question

I'm trying to use the meteor-collectionapi package to update my database. I've set up a basic collection to test out the functionality.
I'm starting with this data:
{ "name" : "Darrell David", "age" : "18", "gender" : "Male", "_id" : "8BW9Yg2oKByBGdnSa" }
{ "name" : "Julie Smith", "age" : "21", "gender" : "Female", "_id" : "fAaFwCEXLzrmejnJK" }
{ "name" : "Todd Davis", "age" : "32", "gender" : "Male", "_id" : "ixKjhkTmjrNte2DjP" }
Now, I want to update the gender of the first player to "Female" so I call this using CURL:
curl -H "X-Auth-Token: 97f0ad9e24ca5e0408a269748d7fe0a0" -X PUT -d "{\"$set\":{\"gender\":\"Female\"}}" http://localhost:3000/collectionapi/players/8BW9Yg2oKByBGdnSa
And what I wind up with is this:
{ "_id" : "8BW9Yg2oKByBGdnSa", "" : { "gender" : "Female" } }
{ "name" : "Julie Smith", "age" : "21", "gender" : "Female", "_id" : "fAaFwCEXLzrmejnJK" }
{ "name" : "Todd Davis", "age" : "32", "gender" : "Male", "_id" : "ixKjhkTmjrNte2DjP" }
The first player has been completely overwritten and the name and age fields have been lost.
What am I missing here? When I execute this command in the MongoDB console it works perfectly:
db.players.update(
{ _id: "8BW9Yg2oKByBGdnSa" },
{ $set: { gender: "Female" } }
)

Answer 1

I'm guessing that bash is replacing "$set" with an empty environment variable
eg. echo "$set" vs echo "\$set"
so update your PUT command to:
curl -H "X-Auth-Token: 97f0ad9e24ca5e0408a269748d7fe0a0" -X PUT -d "{\"\$set\":{\"gender\":\"Female\"}}" http://localhost:3000/collectionapi/players/8BW9Yg2oKByBGdnSa
By default Collection.update() will replace a document if no modifiers are present ($set, $unset, $push, $pull etc). So the command being sent to the server is to replace the document with {"":{"gender":"Female"}}