The only available JS implementation of COSE was designed as a Node.js (CommonJS) module. Since it makes use of some Node-specific APIs, we couldn't simply integrate it using kotlin's npm dependency mechanism. Instead, a few additional steps were needed to integrate it with our kotlin code base.
We utilise a custom build step based on browserify for turning the NodeJS module into a self-contained browser library for consumption from the kotlin side.
The current first draft of the general process follows these steps:
- Create an empty folder ("temp") with a file called "cose_node.js" and add a require call to cose-js:
const cose = require('cose-js');
- Install the cose-js library and all its dependencies in the temp folder:
npm install cose-js
-
Since the current release version of
cose-jsis not browser-compliant, we need to replace the corresponding folder in node_modules with the newest version from the master branch (https://github.com/erdtman/cose-js). -
Now bundle the cose-js lib and all its dependencies into using browserify. Make sure to export the cose-js and buffer libraries:
(in temp)
browserify -r cose-js -r buffer test.js > cose.js
-
Because kotlin-js's webpack integration defines its own require function, the one exported from cose.js (providing the cose-js and Buffer dependencies) now needs to be renamed. Simply replace all occurrences of 'require' with 'extrequire'.
-
Copy the resulting cose.js file to src/jsMain/cose.js in this project
-
Include it in the client html file that consumes the hcert-kotlin js library
-
From Kotlin code, Buffer and COSE can be accessed through js() calls or via corresponding external declarations (TODO)