mingo
Version:
MongoDB query language for in-memory objects
60 lines (59 loc) • 1.96 kB
JavaScript
import { initOptions } from "../../core";
import { assert, has, isObject } from "../../util";
import { $ifNull } from "../expression/conditional/ifNull";
import { $linearFill } from "../window/linearFill";
import { $locf } from "../window/locf";
import { $addFields } from "./addFields";
import { $setWindowFields } from "./setWindowFields";
const FILL_METHODS = {
locf: "$locf",
linear: "$linearFill"
};
const $fill = (collection, expr, options) => {
assert(!expr.sortBy || isObject(expr.sortBy), "sortBy must be an object.");
assert(
!!expr.sortBy || Object.values(expr.output).every((m) => has(m, "value")),
"sortBy required if any output field specifies a 'method'."
);
assert(
!(expr.partitionBy && expr.partitionByFields),
"specify either partitionBy or partitionByFields."
);
assert(
!expr.partitionByFields || expr?.partitionByFields?.every((s) => s[0] !== "$"),
"fields in partitionByFields cannot begin with '$'."
);
options = initOptions(options);
options.context.addExpressionOps({ $ifNull });
options.context.addWindowOps({ $locf, $linearFill });
const partitionExpr = expr.partitionBy || expr?.partitionByFields?.map((s) => `$${s}`);
const valueExpr = {};
const methodExpr = {};
for (const [k, m] of Object.entries(expr.output)) {
if (has(m, "value")) {
valueExpr[k] = { $ifNull: [`$$CURRENT.${k}`, m["value"]] };
} else {
const fillOp = FILL_METHODS[m["method"]];
assert(!!fillOp, `invalid fill method '${m["method"]}'.`);
methodExpr[k] = { [fillOp]: "$" + k };
}
}
if (Object.keys(methodExpr).length > 0) {
collection = $setWindowFields(
collection,
{
sortBy: expr.sortBy || {},
partitionBy: partitionExpr,
output: methodExpr
},
options
);
}
if (Object.keys(valueExpr).length > 0) {
collection = $addFields(collection, valueExpr, options);
}
return collection;
};
export {
$fill
};