I am using sqlite3.js in my clojurescript project, which by necessity involves feeding sqlite3.js into the google closure compiler.

Closure really does not like this line: whwasmutil.js:2058 .

I have guessed that what was intended was the delete method of es6 Map: xcvPart.delete(typeName) rather than the delete operator.

A very nice catch! This is now fixed in both 6576bb2f7bd4d57 and the downstream SQLite3 copy: https://sqlite.org/src/info/99917a5bb04b5

Thank you for the report.