How to use jq to add a value from a variable containing spaces?

Question

bash

json="{}"
foo="Without_spaces"
bar="With spaces"
json=$(jq '.one = "Without_spaces"' <<< $json)
json=$(jq '.two = "With spaces"' <<< $json)
json=$(jq '.foo = "'$foo'"' <<< $json)
# json=$(jq '.bar = "'$bar'"' <<< $json)
jq . <<< $json

The script generates a JSON object. Key values ​​are placed in a variable, then added to an object. And now a situation arose when the variable contains a line with spaces (commented out line). jq throws an error

jq: error: syntax error, unexpected $end, expecting QQSTRING_TEXT or QQSTRING_INTERP_START or QQSTRING_END (Unix shell quoting issues?) at <top-level>, line 1:
.bar = "With        
jq: 1 compile error

If the value with a space is hardcore written in the code, then there is no error (key two)
How to overcome it?

Answer 1

json=$(jq --arg v "$bar" '.bar = $v' <<< $json)