Tone.js: Error when running tests on a clean clone on the typescript branch

Bugs and feature requests only please.

For help questions, check out the forum: https://groups.google.com/forum/#!forum/tonejs

If possible, please include a link which illustrates the issue.

https://jsfiddle.net/1f60jkq4/ (tone@latest) https://jsfiddle.net/z9marxbt/ (tone@next)

Clone branch, checkout typescript, run npm run test.

0 info it worked if it ends with ok
1 verbose cli [ 'C:\\Program Files\\nodejs\\node.exe',
1 verbose cli   'C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js',
1 verbose cli   'run',
1 verbose cli   'karma' ]
2 info using npm@6.9.0
3 info using node@v10.16.0
4 verbose run-script [ 'prekarma', 'karma', 'postkarma' ]
5 info lifecycle tone@14.3.0~prekarma: tone@14.3.0
6 info lifecycle tone@14.3.0~karma: tone@14.3.0
7 verbose lifecycle tone@14.3.0~karma: unsafe-perm in lifecycle true
8 verbose lifecycle tone@14.3.0~karma: PATH: C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\node-gyp-bin;C:\Users\jeffs\projects\Tone.js\node_modules\.bin;C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\node-gyp-bin;C:\Users\jeffs\projects\Tone.js\node_modules\.bin;C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\nodejs\;C:\Users\jeffs\AppData\Local\Microsoft\WindowsApps;C:\Users\jeffs\AppData\Local\Programs\Microsoft VS Code\bin;C:\Users\jeffs\AppData\Roaming\npm;C:\Program Files\Git\mingw64\bin;
9 verbose lifecycle tone@14.3.0~karma: CWD: C:\Users\jeffs\projects\Tone.js
10 silly lifecycle tone@14.3.0~karma: Args: [ '/d /s /c',
10 silly lifecycle   'karma start scripts/karma.conf.js --single-run --file $npm_config_file --dir $npm_config_dir' ]
11 silly lifecycle tone@14.3.0~karma: Returned: code: 1  signal: null
12 info lifecycle tone@14.3.0~karma: Failed to exec karma script
13 verbose stack Error: tone@14.3.0 karma: `karma start scripts/karma.conf.js --single-run --file $npm_config_file --dir $npm_config_dir`
13 verbose stack Exit status 1
13 verbose stack     at EventEmitter.<anonymous> (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\index.js:301:16)
13 verbose stack     at EventEmitter.emit (events.js:198:13)
13 verbose stack     at ChildProcess.<anonymous> (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\lib\spawn.js:55:14)
13 verbose stack     at ChildProcess.emit (events.js:198:13)
13 verbose stack     at maybeClose (internal/child_process.js:982:16)
13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
14 verbose pkgid tone@14.3.0
15 verbose cwd C:\Users\jeffs\projects\Tone.js
16 verbose Windows_NT 10.0.18362
17 verbose argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "run" "karma"
18 verbose node v10.16.0
19 verbose npm  v6.9.0
20 error code ELIFECYCLE
21 error errno 1
22 error tone@14.3.0 karma: `karma start scripts/karma.conf.js --single-run --file $npm_config_file --dir $npm_config_dir`
22 error Exit status 1
23 error Failed at the tone@14.3.0 karma script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 1, true ]

Is there some other setup other than npm install that I need to run tests? I want to contribute but I cannot get started.