GODRIVER-3071 Correct uint Encoding BSON Documentation (#1500)

Co-authored-by: Matt Dale <[email protected]>

bson/doc.go

@@ -68,10 +68,9 @@
 //  2. int8, int16, and int32 marshal to a BSON int32.
 //  3. int marshals to a BSON int32 if the value is between math.MinInt32 and math.MaxInt32, inclusive, and a BSON int64
 //     otherwise.
-//  4. int64 marshals to BSON int64.
+//  4. int64 marshals to BSON int64 (unless [Encoder.IntMinSize] is set).
 //  5. uint8 and uint16 marshal to a BSON int32.
-//  6. uint, uint32, and uint64 marshal to a BSON int32 if the value is between math.MinInt32 and math.MaxInt32,
-//     inclusive, and BSON int64 otherwise.
+//  6. uint, uint32, and uint64 marshal to a BSON int64 (unless [Encoder.IntMinSize] is set).
 //  7. BSON null and undefined values will unmarshal into the zero value of a field (e.g. unmarshalling a BSON null or
 //     undefined value into a string will yield the empty string.).
 //

bson/encoder_example_test.go

@@ -251,3 +251,33 @@ func ExampleEncoder_multipleExtendedJSONDocuments() {
 	// {"x":{"$numberInt":"3"},"y":{"$numberInt":"4"}}
 	// {"x":{"$numberInt":"4"},"y":{"$numberInt":"5"}}
 }
+
+func ExampleEncoder_IntMinSize() {
+	// Create an encoder that will marshal integers as the minimum BSON int size
+	// (either 32 or 64 bits) that can represent the integer value.
+	type foo struct {
+		Bar uint32
+	}
+
+	buf := new(bytes.Buffer)
+	vw, err := bsonrw.NewBSONValueWriter(buf)
+	if err != nil {
+		panic(err)
+	}
+
+	enc, err := bson.NewEncoder(vw)
+	if err != nil {
+		panic(err)
+	}
+
+	enc.IntMinSize()
+
+	err = enc.Encode(foo{2})
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(bson.Raw(buf.Bytes()).String())
+	// Output:
+	// {"bar": {"$numberInt":"2"}}
+}