Explicit source options overwrite

[jingsam]

Explicit source options should taken precedence over TileJSON. See details in #8192

Launch Checklist

• briefly describe the changes in this PR
• write tests for all new functionality
• document any changes to public APIs
• post benchmark scores
• manually test the debug page
• tagged @mapbox/studio and/or @mapbox/maps-design if this PR includes style spec changes
• tagged @mapbox/gl-native if this PR includes shader changes or needs a native port

[asheemmamoowala]

Why is unknown properties support needed?

[jingsam]

I think foreign members (unknown properties) in source options should be leaved as it is. Foreign members does not affect source's functionality and add extensibility for metadata or custom sources. As we don't invalidate foreign members in geojson、image、video sources, invalidate foreign members in vector, raster, raster-dem seems inconsistent.

[asheemmamoowala]

@jingsam Sorry for the delay in getting back to this. Allowing foreign members in the TileJSON does not seem necessary as part of this PR. It is preferable to have strict validation to ensure that unnecesary or incorrect properties are not being added to such files.

[asheemmamoowala]

cc @mapbox/studio

[asheemmamoowala]

Good to go except the foreign properties test.

[jingsam]

@asheemmamoowala I have invalid foreign members in source options when url is defined. As you can see, I have enum so many possible valid members. This code is fragile as someday we may need new property in test cases or application. If we now restrict properties allowed in sources options, that may make sources options can not be extended. Actually, in mapbox-style-spec, there is no limitation on foreign properties. So limit in here is sounds unreasonable. Forregin properties are hurtless, if mapbox-gl-js does not use them, take as it is but not restrict them.

mapbox-gl-js/src/style-spec/validate/validate_source.js

Lines 32 to 38 in 58fa110

	if ('url' in value) {
	for (const prop in value) {
	if (['type', 'url', 'tiles', 'minzoom', 'maxzoom', 'attribution', 'mapbox_logo', 'bounds', 'scheme', 'tileSize', 'encoding'].indexOf(prop) < 0) {
	errors.push(new ValidationError(`${key}.${prop}`, value[prop], `a source with a "url" property may not include a "${prop}" property`));
	}
	}
	}

[asheemmamoowala]

@jingsam Thank you for sticking to your guns on this. Just rechecked the TilJSON spec. It states that

Implementations MUST treat unknown keys as if they weren't present.

LGTM!

[asheemmamoowala]

Actually - could you add a render test to ensure that the over-ride properties take effect. An example that uses constrains maxzoom or bounds would work well with a small image size.

[jingsam]

@asheemmamoowala I add a test, please check out.