jsonnetunit needle haystack lookup.

containsEnvVars

{
  // containsEnvVars checks that all needles (k8s env variable "name" and "value" objs) exist in the haystack (pod env block) object
  // i.e. asserts structs exist in array
  containsEnvVars(haystack, needles):: (
    // create an array, 1 element per needle
    local results = [
      // check the needle is valid (it contains the two required fields)
      if (std.objectHas(needle, 'name') && std.objectHas(needle, 'value')) then
        // needle is valid

        // create a sub array to contain result of every haystack item for the current needle
        local h = [
          // if the haystack name and value both match the needle, add 'true' to the sub array
          if (needle.name == haystackItem.name) && needle.value == haystackItem.value then true
          for haystackItem in haystack
        ];
        // strip out the nulls, leaving only a true for the items where the needle and haystack match
        local prunedResults = std.prune(h);

        if std.length(prunedResults) == 0 then
           error "needle: " + needle + " was not found in the haystack"
        else
          true
      else
        // needle is not value, raise an error
        error 'needle ' + needle + ': doesnt contain the fields "name" and "value"'
      // body of the loop is the above logic
      for needle in needles
    ];

    // remove the empty sub arrays, these are where a needle was not matched to a haystackItem
    // therefore indicate a needle wasn't found
    local prunedResults = std.prune(results);

    //the number of results (bool true) remaining should equal the number of needles, indicating they were all found
    if std.count(prunedResults, true) < std.length(needles) then
      false
    else
      true
  )
}

exampleUsage

# Make sure the envVars contain ADDITIONAL_ENV: ADDITIONAL_VALUE without having to compare the entire map
testAdditionalEnvVars: {
  local exampleVars: [
    { "name": "DB_HOST",        "value": "thedb.domain.com"          },
    { "name": "DB_PORT",        "value": 3306                        },
    { "name": "REDIS_HOST",     "value": "redis.anotherdomain.local" },
    { "name": "REDIS_PORT",     "value": 6379                        },
    { "name": "ADDITIONAL_ENV", "value": "ADDITIONAL_VALUE"          }
]

  actual: utils.containsEnvVars(exampleVars, [{ name: 'ADDITIONAL_ENV', value: 'ADDITIONAL_VALUE' }]),
  expect: true,
},