@protobuf-ts/runtime/build/es2015/reflection-merge-partial.js

Runtime library for code generated by the protoc plugin "protobuf-ts"

/**
 * Copy partial data into the target message.
 *
 * If a singular scalar or enum field is present in the source, it
 * replaces the field in the target.
 *
 * If a singular message field is present in the source, it is merged
 * with the target field by calling mergePartial() of the responsible
 * message type.
 *
 * If a repeated field is present in the source, its values replace
 * all values in the target array, removing extraneous values.
 * Repeated message fields are copied, not merged.
 *
 * If a map field is present in the source, entries are added to the
 * target map, replacing entries with the same key. Entries that only
 * exist in the target remain. Entries with message values are copied,
 * not merged.
 *
 * Note that this function differs from protobuf merge semantics,
 * which appends repeated fields.
 */
export function reflectionMergePartial(info, target, source) {
    let fieldValue, // the field value we are working with
    input = source, output; // where we want our field value to go
    for (let field of info.fields) {
        let name = field.localName;
        if (field.oneof) {
            const group = input[field.oneof]; // this is the oneof`s group in the source
            if ((group === null || group === void 0 ? void 0 : group.oneofKind) == undefined) { // the user is free to omit
                continue; // we skip this field, and all other members too
            }
            fieldValue = group[name]; // our value comes from the the oneof group of the source
            output = target[field.oneof]; // and our output is the oneof group of the target
            output.oneofKind = group.oneofKind; // always update discriminator
            if (fieldValue == undefined) {
                delete output[name]; // remove any existing value
                continue; // skip further work on field
            }
        }
        else {
            fieldValue = input[name]; // we are using the source directly
            output = target; // we want our field value to go directly into the target
            if (fieldValue == undefined) {
                continue; // skip further work on field, existing value is used as is
            }
        }
        if (field.repeat)
            output[name].length = fieldValue.length; // resize target array to match source array
        // now we just work with `fieldValue` and `output` to merge the value
        switch (field.kind) {
            case "scalar":
            case "enum":
                if (field.repeat)
                    for (let i = 0; i < fieldValue.length; i++)
                        output[name][i] = fieldValue[i]; // not a reference type
                else
                    output[name] = fieldValue; // not a reference type
                break;
            case "message":
                let T = field.T();
                if (field.repeat)
                    for (let i = 0; i < fieldValue.length; i++)
                        output[name][i] = T.create(fieldValue[i]);
                else if (output[name] === undefined)
                    output[name] = T.create(fieldValue); // nothing to merge with
                else
                    T.mergePartial(output[name], fieldValue);
                break;
            case "map":
                // Map and repeated fields are simply overwritten, not appended or merged
                switch (field.V.kind) {
                    case "scalar":
                    case "enum":
                        Object.assign(output[name], fieldValue); // elements are not reference types
                        break;
                    case "message":
                        let T = field.V.T();
                        for (let k of Object.keys(fieldValue))
                            output[name][k] = T.create(fieldValue[k]);
                        break;
                }
                break;
        }
    }
}