AMD compatibility broken in 1.8.1.

[mbostock]

Viz.js 1.8.1 adds a new UMD block that 1.8.0 didn’t have:

if (typeof exports === 'object' && typeof module === 'object')
  module.exports = Module;
else if (typeof define === 'function' && define['amd'])
  define([], function() { return Module; });
else if (typeof exports === 'object')
  exports["Module"] = Module;

But Viz.js 1.8.1 retains the global / CommonJS export block from previous releases:

if (typeof module === "object" && module.exports) {
  module.exports = Viz;
} else {
  global.Viz = Viz;
}

As a result, in an AMD environment (such as when using d3-require inside of Observable), loading Viz.js 1.8.1 returns the Module object (created by Emscripten?) rather than the expected Viz object.

Replacing both blocks with something like this should work:

if (typeof exports === 'object' && typeof module !== 'undefined') {
  module.exports = Viz;
} else if (typeof define === 'function' && define.amd) {
  define(function() { return Viz; });
} else {
  global.Viz = Viz;
}

(I often use Rollup to generate UMD bundles from ES modules; see @observablehq/graphviz for an example.)

[mbostock]

I see you’re already using Rollup for 2.0.0, hooray! So feel free to close this if you don’t feel a need to ship a patch release for v1. 😄

[mdaines]

@mbostock I've released 1.8.2, which I think should address this.

I am using Rollup for 2.0.0, but I'm also splitting the Emscripten stuff into a separate file so it can be used as a Web Worker. That doesn't quite work in Observable yet as I just found out. I've created an issue for that here: #131

[magjac]

Thanks a lot. Here is evidence that it's working:
https://beta.observablehq.com/@magjac/d3-graphviz-fiddling-not-working
https://talk.observablehq.com/t/global-is-undefined-when-using-viz-js-through-d3-graphviz/706/16?u=magjac