JQ, how to count depending on conditions? - json

Question

Using jq, I need to get the count within an array depending on two criterias: it MUST have status === 'skipped' && ref.includes(version)
[
{
"id": 15484,
"sha": "52606c8da57984d1243f436e5d12e275db29a6e0",
"ref": "v1.4.15",
"status": "canceled"
},
{
"id": 15483,
"sha": "52606c8da57984d1243f436e5d12e275db29a6e0",
"ref": "v1.4.15",
"status": "canceled"
},
{
"id": 15482,
"sha": "1b4ccc1dc17e9b8ddb24550c5566d2be6b03465e",
"ref": "dev",
"status": "success"
},
{
"id": 15481,
"sha": "5b6ec939739c5a1513634f3b58bf96522917571d",
"ref": "dev",
"status": "failed"
},
{
"id": 15480,
"sha": "ec18d46f491a4645c68388df91fc41455b421e71",
"ref": "dev",
"status": "failed"
},
{
"id": 15479,
"sha": "dd83a6d6e58cc5114aed8016341ab3c5b3ebb702",
"ref": "dev",
"status": "failed"
},
{
"id": 15478,
"sha": "18ccaf4bc37bf65470b2c6ddaa69e5b4018354a7",
"ref": "dev",
"status": "success"
},
{
"id": 15477,
"sha": "f90900d733bce2be3d9ba9db25f8b51296bc6f3f",
"ref": "dev",
"status": "failed"
},
{
"id": 15476,
"sha": "3cf0431a161e6c9ca90e8248af7b4ec39c54bfb1",
"ref": "dev",
"status": "failed"
},
{
"id": 15285,
"sha": "d24b46edc75d8f7308dbef37d7b27625ef70c845",
"ref": "dev",
"status": "success"
},
{
"id": 15265,
"sha": "52606c8da57984d1243f436e5d12e275db29a6e0",
"ref": "v1.4.15",
"status": "success"
},
{
"id": 15264,
"sha": "9a15f8d4c950047f88c642abda506110b9b0bbd7",
"ref": "v1.4.15-static",
"status": "skipped"
},
{
"id": 15263,
"sha": "9a15f8d4c950047f88c642abda506110b9b0bbd7",
"ref": "v1.4.15-static",
"status": "skipped"
},
{
"id": 15262,
"sha": "76451d2401001c4c51b9800d3cdf62e4cdcc86ba",
"ref": "v1.4.15-no-js",
"status": "skipped"
},
{
"id": 15261,
"sha": "76451d2401001c4c51b9800d3cdf62e4cdcc86ba",
"ref": "v1.4.15-no-js",
"status": "skipped"
},
{
"id": 15260,
"sha": "515cd1b00062e9cbce05420036f5ecc7a898a4bd",
"ref": "v1.4.15-cli",
"status": "skipped"
},
{
"id": 15259,
"sha": "515cd1b00062e9cbce05420036f5ecc7a898a4bd",
"ref": "v1.4.15-cli",
"status": "skipped"
},
{
"id": 15258,
"sha": "b67acd3082da795f022fafc304d267d3afd6b736",
"ref": "v1.4.15-node",
"status": "skipped"
},
{
"id": 15257,
"sha": "b67acd3082da795f022fafc304d267d3afd6b736",
"ref": "v1.4.15-node",
"status": "skipped"
},
{
"id": 15256,
"sha": "4da4a788a85d82527ea568fed4f03da193842a80",
"ref": "v1.4.15-bs-redux-saga-router-dom-intl",
"status": "skipped"
}
]
We also like to use environment variable for the query :
status=skipped
ref=v1.4.15
This work but without environment variable options:
cat test.json | jq '[.[] | select(.status=="skipped") | select(.ref | startswith("v1.4.15"))] | length'
How is this possible?
Answer:
status=skipped; ref=v1.4.15; cat test.json | jq --arg REF "$ref" --arg STATUS "$status" -r '[.[] | select(.status==$STATUS) | select(.ref | startswith($REF))] | length'

Answer 1

Use the length() function at the end of the filter, after putting the objects list into an array
jq '[.[] | select(.status == "skipped") | select(.ref | test("1\\.4\\.15"))] | length'
but for just returning the objects leave out the logic to get the length
jq '[.[] | select(.status == "skipped") | select(.ref | test("1\\.4\\.15"))]'
The test() is a more powerful way to match your regex with JSON strings. The startswith() or endswith() can't match strings if they are in the middle.
Using variables,
ref="1\.4\.15"
jq --arg status "$status" --arg ref "$ref" \
'[.[] | select(.status == $status) | select(.ref | test($ref))]|length' json

Answer 2

By using map(select(...) or equivalent, you could use length, but it is generally more efficient to use a generic counting function, such as:
def sigma(s): reduce s as $s (null; .+$s);
sigma(.[] | select(.status=="skipped" and (.ref | startswith("v1.4.15") )) | 1)
Using shell and environment variables
Using shell and environment variables is covered in the jq manual, but in brief, one way to pass in string values is using the command-line option --arg, e.g. along the lines of:
jq --arg status "$status" --arg ref "$ref" -f program.jq test.json

Answer 3

I know jq is popular around here, but may I suggest xidel? See http://videlibri.sourceforge.net/xidel.html.
Just like jq it's a JSON interpreter, but besides JSONiq you can also use XPath/Xquery functions to do all sorts of cool stuff.
This would list all objects with the 2 criteria:
xidel -s test.json -e '$json()[status="skipped" and starts-with(ref,"v1.4.15")]'
To count them, simply enclose the query with the count() function:
xidel -s test.json -e 'count($json()[status="skipped" and starts-with(ref,"v1.4.15")])'
This returns 9.
With variables:
status=skipped
ref=v1.4.15
xidel -s test.json -e 'count($json()[status="'$status'" and starts-with(ref,"'$ref'")])'

Answer 4

For the sake of completeness, this would be an equivalent JSONiq query:
let $a := [
(: copy-paste the entire array here in plain JSON syntax --
omitted for the sake of brevity :)
]
return count(
for $obj in $a[]
where $obj.status eq "skipped"
and
matches($obj.ref, "ˆv")
return $obj
)