PostGIS ST_AsMVT JSONB properties encoding bug

index.js

const fs = require("fs");
const geobuf = require("geobuf");
const Protobuf = require("pbf");
const pgp = require("pg-promise")();
const vt = require("vector-tile");

const db = pgp(process.env.DATABASE_URL);

const tile_with_properties_as_jsonb = `WITH data (id, num1, num2, geom) AS (
	VALUES
		(1, 1.1, 0.1, ST_GeomFromEWKT('SRID=3857;POINT(1 1)')),
		(2, 2.2, 0.2, ST_GeomFromEWKT('SRID=3857;POINT(2 2)')),
		(3, 3.3, 0.3, ST_GeomFromEWKT('SRID=3857;POINT(3 3)'))
	)
SELECT
	ST_AsMVT(tile, 'data', 4096, 'geom') FROM (
		SELECT
			ST_AsMVTGeom(
				geom,
				ST_GeomFromEWKT('SRID=3857;POLYGON((-20037508.34 20037508.34,-20037508.34 -20037508.34,20037508.34 -20037508.34,20037508.34 20037508.34,-20037508.34 20037508.34))'),
				4096,
				0,
				true
			) as geom,
			jsonb_build_object(
				'id', id,
				'num1', num1,
				'num2', num2
			) as properties
		FROM data
	) as tile;`;

const tile_with_properties_as_json = `WITH data (id, num1, num2, geom) AS (VALUES
		(1, 1.1, 0.1, ST_GeomFromEWKT('SRID=3857;POINT(1 1)')),
		(2, 2.2, 0.2, ST_GeomFromEWKT('SRID=3857;POINT(2 2)')),
		(3, 3.3, 0.3, ST_GeomFromEWKT('SRID=3857;POINT(3 3)'))
	)
SELECT
	ST_AsMVT(tile, 'data', 4096, 'geom') FROM (
		SELECT
			ST_AsMVTGeom(
				geom,
				ST_GeomFromEWKT('SRID=3857;POLYGON((-20037508.34 20037508.34,-20037508.34 -20037508.34,20037508.34 -20037508.34,20037508.34 20037508.34,-20037508.34 20037508.34))'),
				4096,
				0,
				true
			) as geom,
			json_build_object(
				'id', id,
				'num1', num1,
				'num2', num2
			) as properties
		FROM data
	) as tile;`;

const tile_with_plain_properties = `WITH data (id, num1, num2, geom) AS (
	VALUES
		(1, 1.1, 0.1, ST_GeomFromEWKT('SRID=3857;POINT(1 1)')),
		(2, 2.2, 0.2, ST_GeomFromEWKT('SRID=3857;POINT(2 2)')),
		(3, 3.3, 0.3, ST_GeomFromEWKT('SRID=3857;POINT(3 3)'))
)
SELECT
	ST_AsMVT(tile, 'data', 4096, 'geom') FROM (
		SELECT
			ST_AsMVTGeom(
				geom,
				ST_GeomFromEWKT('SRID=3857;POLYGON((-20037508.34 20037508.34,-20037508.34 -20037508.34,20037508.34 -20037508.34,20037508.34 20037508.34,-20037508.34 20037508.34))'),
				4096,
				0,
				true
			) as geom,
			id,
			num1,
			num2
		FROM data
	) as tile;`;

const tile2geojson = buffer => {
  const tile = new vt.VectorTile(new Protobuf(buffer));
  const layers = Object.keys(tile.layers);

  var collection = { type: "FeatureCollection", features: [] };

  layers.forEach(function(layerID) {
    var layer = tile.layers[layerID];
    if (layer) {
      for (var i = 0; i < layer.length; i++) {
        var feature = layer.feature(i).toGeoJSON(0, 0, 0);
        if (layers.length > 1) feature.properties.vt_layer = layerID;
        collection.features.push(feature);
      }
    }
  });

  return collection;
};

Promise.all([
  db
    .one(tile_with_properties_as_json)
    .then(results => results.st_asmvt)
    .then(tile2geojson),
  db
    .one(tile_with_properties_as_jsonb)
    .then(results => results.st_asmvt)
    .then(tile2geojson),
  db
    .one(tile_with_plain_properties)
    .then(results => results.st_asmvt)
    .then(tile2geojson)
])
  .then(results => {
    const [json, jsonb, plain] = results;

    fs.writeFileSync("tile_json.geojson", JSON.stringify(json, null, 2));
    fs.writeFileSync("tile_jsonb.geojson", JSON.stringify(jsonb, null, 2));
    fs.writeFileSync("tile_plain.geojson", JSON.stringify(plain, null, 2));
  })
  .then(() => db.$pool.end());

tile_json.geojson

tile_json.sql

WITH data (id, num1, num2, geom) AS (
	VALUES
		(1, 1.1, 0.1, ST_GeomFromEWKT('SRID=3857;POINT(1 1)')),
		(2, 2.2, 0.2, ST_GeomFromEWKT('SRID=3857;POINT(2 2)')),
		(3, 3.3, 0.3, ST_GeomFromEWKT('SRID=3857;POINT(3 3)'))
)
SELECT
	ST_AsMVT(tile, 'data', 4096, 'geom') FROM (
		SELECT
			ST_AsMVTGeom(
				geom,
				ST_GeomFromEWKT('SRID=3857;POLYGON((-20037508.34 20037508.34,-20037508.34 -20037508.34,20037508.34 -20037508.34,20037508.34 20037508.34,-20037508.34 20037508.34))'),
				4096,
				0,
				true
			) as geom,
			json_build_object(
				'id', id,
				'num1', num1,
				'num2', num2
			) as properties
		FROM data
	) as tile;

tile_jsonb.geojson

tile_jsonb.sql

WITH data (id, num1, num2, geom) AS (
	VALUES
		(1, 1.1, 0.1, ST_GeomFromEWKT('SRID=3857;POINT(1 1)')),
		(2, 2.2, 0.2, ST_GeomFromEWKT('SRID=3857;POINT(2 2)')),
		(3, 3.3, 0.3, ST_GeomFromEWKT('SRID=3857;POINT(3 3)')) 
)
SELECT
	ST_AsMVT(tile, 'data', 4096, 'geom') FROM (
		SELECT
			ST_AsMVTGeom(
				geom,
				ST_GeomFromEWKT('SRID=3857;POLYGON((-20037508.34 20037508.34,-20037508.34 -20037508.34,20037508.34 -20037508.34,20037508.34 20037508.34,-20037508.34 20037508.34))'),
				4096,
				0,
				true
			) as geom,
			jsonb_build_object(
				'id', id,
				'num1', num1,
				'num2', num2
			) as properties
		FROM data
	) as tile;

tile_plain.geojson

tile_plain.sql

WITH data (id, num1, num2, geom) AS (
	VALUES
		(1, 1.1, 0.1, ST_GeomFromEWKT('SRID=3857;POINT(1 1)')),
		(2, 2.2, 0.2, ST_GeomFromEWKT('SRID=3857;POINT(2 2)')),
		(3, 3.3, 0.3, ST_GeomFromEWKT('SRID=3857;POINT(3 3)'))
)
SELECT
	ST_AsMVT(tile, 'data', 4096, 'geom') FROM (
		SELECT
			ST_AsMVTGeom(
				geom,
				ST_GeomFromEWKT('SRID=3857;POLYGON((-20037508.34 20037508.34,-20037508.34 -20037508.34,20037508.34 -20037508.34,20037508.34 20037508.34,-20037508.34 20037508.34))'),
				4096,
				0,
				true
			) as geom,
			id,
			num1,
			num2
		FROM data
	) as tile;