Empty html report using version 14+ (fine with v13 and below)

Link to bug demonstration repository

https://github.com/areel/nyc-bug-demo.git

Expected Behavior

issuing

nyc report --reporter=html

should generate a full report based on content of

./nyc_out/out.json

Observed Behavior

Using versions 14.0.0 and higher an empty html report is produced, Using latest releases of 10.X, 11.X, 12.x and 13.x all work as expected

Steps to observe issue

I have edited the original out.json to have only one instrumented module and edited the reference path to allow drilling into module. Follow steps below to see issue.

• clone repo
• yarn (using version 14.0.0 of nyc)
• yarn report
• coverage/index.html (does not contain expected content)
• coverage/alert.constants.ts.html (does not exist)
• delete yarn.lock
• delete node_modules
• delete coverage
• edit package.json dev dependency to be

"devDependencies": {
           "nyc": "^13.0.0"
}

• save package.json !!
• yarn
• yarn report
• code coverage html report is correct
  • index.html has reference to alert.constants.ts.html
  • alert.constants.ts.html exists in coverage folder

Troubleshooting steps

• still occurring when I put cache: false in my nyc config
• does not occur in latest release of versions 10,11,12 and 13

Environment Information

System:
    OS: Linux 5.0 Manjaro Linux undefined
    CPU: (16) x64 AMD Ryzen 7 1700 Eight-Core Processor
    Memory: 11.33 GB / 31.40 GB
  Binaries:
    Node: 11.6.0 - ~/.asdf/shims/node
    Yarn: 1.13.0 - ~/.yarn/bin/yarn
    npm: 6.9.0 - ~/.asdf/shims/npm

[coreyfarrell]

@areel please add "extension": [".ts"] to your nyc configuration. This is required in nyc@14 otherwise .ts files will be filtered out of the report. Note that this will be fixed in nyc@15, unfortunately we could not expand the default extension list in nyc@14 due to concern that it might break something.

[areel]

Can confirm that worked, thanks to both of you for your time.