Uncaught (in promise) RuntimeError: abort(CompileError: WebAssembly.instantiate(): expected magic word 00 61 73 6d...

Apologies for the vague bug report but I’m seeing this error and not finding a whole lot on google. 'Figured I’d at least file something here as a breadcrumb for others.

Context: I have a JS webapp that used to use the <script source="... style of importing d3, @hpcc/wasm, and d3-graphviz. 'Worked great. Now I’m porting it over to ES modules, using parcel for bundling, and it’s throwing the above error.

I assume this is because I’m not pulling in the @hpcc/wasm content properly, but not really sure what’s going on.

Installation: npm i parcel@nightly d3 @hpcc/wasm d3-graphviz

Usage:

import * as d3 from 'd3';
import '@hpcc/wasm';
import 'd3-graphviz';

// 'Not 100% sure these are the right incantations for importing these modules,
// but it gives d3 a 'graphviz' property so... I guess it's working?

const graphviz = d3.select('#graph')
      .graphviz() //     <--  ERROR THROWN HERE?
      .renderDot(dotMarkup);

---

There’s a few other warnings and whatnot in Chrome’s console as well. 'Not sure if they’re relevent…

[magjac]

Thanks all for sharing. The little I know about this, I’ve learnt through @hpcc-js/wasm and Gordon so I have nothing to add other than that I’ve solved something similar with symbolic links in the d3-graphviz tests and in the graphviz-visual-editor.

If you have any suggestion for how to improve d3-graphviz in this respect, please file an enhancement issue about it and I will happily implement it. Or submit a PR if you know how to do it.

[GordonSmith]

FWIW - the way I think of graphvizlib.wasm dependency is the same as any non JS resource (like an image, video or audio file) and that it needs to get copied to the public / dist folder as part of your bundle process. (If it ends up in the same folder as the bundled JS code then it should “just work”). If you do want to locate it in a different location then there are methods available to specify those. It is important that matching versions of the JS and WASM files are maintained (which as pointed out was the cause of your error above).