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Type: Improvement
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Resolution: Won't Fix
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Priority: Unknown
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None
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Affects Version/s: None
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Component/s: Docs
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Completed
The "fully runnable example" from the Find Multiple Documents usage example page declares the results slice that is passed to `cursor.All` as
var results []bson.M
Despite the Go driver API documentation for `cursor.All` saying that the referenced slice will be "completely overwritten", in the case of no results, `results` will remain in an uninitialized state, which will be encoded as `null` in json (and bson). In contrast, if the results slice is declared as
var results []bson.M = make([]bson.M, 0, 0) // or, equivalently results := make([]bson.M, 0, 0)
in the case of no results, `results` will be fully initialized, and will be encoded as `[]` (the empty array) in json.
I am not sure whether this difference in behavior for the empty result set is intentional or avoidable. If it is intentional, then I think we may want to update our documentation to point out this gotcha more clearly (both in driver API docs and the examples page) and/or update our example to use the fully initialized results declaration, so that users who are relying on a consistent data structure, e.g., for returning the response in json format via a REST API, aren't led into this pitfall.
- related to
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GODRIVER-2589 cursor.All code in the find API usage example leads users to a Go gotcha in the case of no results
- Closed