Create flag for packages to detect which platform is being used.

[soapdog]

Soon there will be multiple platforms inside platforms/ each providing the same ssb.* high-level API with internals tweaked for specific SSB server implementations.

The plan is to have the following platforms:

• nodejs-ssb: which is a refactor of the current available codebase. Cue Improve platforms/nodejs-ssb #105
• go-ssb: future implementation for go-ssb based server.
• browser-ssb: future implementation based on client-side only ssb-browser-core.

Each package will declare which platforms it is compatible with, and won't be loaded when an incompatible platform is used.

The package declaration will include a new property supportedPlatforms which is an array of platform identifiers. Example:

supportedPlatforms: ["nodejs-ssb", "go-ssb"]

The running platform will be available at runtime as ssb.serverType so that code can branch.

• implement supportedPlatforms package flag.
• implement ssb.serverType runtime property.

[soapdog]

This issue is done!

There is both ssb.serverType which is a String that should match the values in pkg.supportedPlatforms which is an Array of Strings. At the moment the only serverType is nodejs-ssb, but this is necessary groundwork to allow us to run other backends soon. It also enables package develolpers to branch their code depending on the server type and thus be able to support more than one server, example:

if (ssb.serverType === "nodejs-ssb") {
 // do something that is supported only on that server.
}

---

All packages have been patched to include a supportedPlatforms property.

[soapdog]

This flag has been changed from serverType to platform to be consistent with the supportedPlatforms property in the package declaration.