Create one JSON from another, with extra data va JQ - json

Question

I have this file:
[
"smoke-tests",
"push-apps-manager"
]
I'd like to get this output using JQ:
{
"errands": [
{"name": "smoke-tests", "post_deploy": true},
{"name": "push-apps-manager", "post_deploy": true}
]
}
It seems so simple, yet, I have so much difficulty here...

Answer 1

It's a little tricky, since you need to embed the input into the list bound to the errands key. Start by creating the sequence of name/post_deploy objects:
% jq '.[] | {name: ., post_deploy: true}' names.json
{
"name": "smoke-tests",
"post_deploy": true
}
{
"name": "push-apps-manager",
"post_deploy": true
}
Then wrap that in the list in the outer object:
% jq '{errands: [.[] | {name: ., post_deploy: true}]}' names.json
{
"errands": [
{
"name": "smoke-tests",
"post_deploy": true
},
{
"name": "push-apps-manager",
"post_deploy": true
}
]
}
You can also use the map function (which I rarely remember how to use correctly, but it turns out is pretty simple here):
% jq '{errands: map({name:., post_deploy: true})}' names.json

Answer 2

Here is another approach. If you are new to jq it may be easiest to work towards the goal in small steps.
1) Start with the identity filter
.
which produces as expected
[
"smoke-tests",
"push-apps-manager"
]
2) next add the outer object with the "errands" key:
{ "errands": . }
which produces
{
"errands": [
"smoke-tests",
"push-apps-manager"
]
}
3) next move the data into an array
{ "errands": [ . ] }
which produces
{
"errands": [
[
"smoke-tests",
"push-apps-manager"
]
]
}
4) add the inner object with the "name" and "post_deploy" keys
{ "errands": [ { "name": ., "post_deploy": true } ] }
which produces
{
"errands": [
{
"name": [
"smoke-tests",
"push-apps-manager"
],
"post_deploy": true
}
]
}
5) Now we're really close. All we need to do is take advantage of jq's Object Construction behavior when an expression produces multiple results :
{ "errands": [ { "name": .[], "post_deploy": true } ] }
which gives us the desired result
{
"errands": [
{
"name": "smoke-tests",
"post_deploy": true
},
{
"name": "push-apps-manager",
"post_deploy": true
}
]
}