`tns plugin add` fails when tns-android key is missing in package.json of the app

Did you verify this is a real problem by searching

Yes, here.

Tell us about the problem

I do a lot of plugin development ;-) I tend to do
tns plugin add ../src or tns plugin add pluginname-1.0.0.tgz
All of these will cause nativescript to throw a error

TypeError: Cannot read property 'version' of undefined
    at PluginsService.getInstalledFrameworkVersion (/usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:261:29)
    at PluginsService.isPluginDataValidForPlatform (/usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:265:48)
    at PluginsService.<anonymous> (/usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:57:26)
    at next (native)
    at /usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:7:71
    at __awaiter (/usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:3:12)
    at action (/usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:56:83)
    at PluginsService.<anonymous> (/usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:253:27)
    at next (native)
    at /usr/local/lib/node_modules/nativescript/lib/services/plugins-service.js:7:71

The issue is inserted in the package.json: "nativescript-pluginname": "file:<path to dir>",

When you attempt to get version numbers, "file:....." doesn't match and causes the above error.

Which platform(s) does your issue occur on?

Both

Please provide the following version numbers that your issue occurs with:

At least since TNS 3.0, still happening in 3.2

Please tell us how to recreate the issue in as much detail as possible.

tns plugin add ../src from a demo folder

lib/services/plugins-service.js から始め、特に PluginsService.getInstalledFrameworkVersion と isPluginDataValidForPlatform を確認してから、デモアプリで tns plugin add ../src を実行して再現します。アプリの package.json に tns-android キーがない場合に、file: 依存関係がどのように処理されるかを追跡します。どちらのプラットフォームでも、ローカルディレクトリおよび tarball からのプラグイン追加で undefined-version エラーが発生しなくなれば完了です。