no-unused-variable rule does not appear to work

[VisionRidge]

I added "no-unused-variable": true rule to tslint.json, but rule does not appear to raise warnings
https://palantir.github.io/tslint/rules/no-unused-variable/

[rich-newman]

The no-unused-variable rule has always been problematic, and at one stage the tslint team were going to deprecate it completely. It's now a semantic rule. It thus only works if you use tsconfig.json files to define your project.

I tried myself and I did manage to get no-unused-variable to work in the TypeScript Analyzer. Follow the steps below:

• Create a new TypeScript 'Blank Node.js Console Application' project
• Change app.ts so it contains only the one line of code below:
  function test() { const a = 5; }
• Add a tsconfig.json file: the default Visual Studio one is fine (Add/New Item on the project context menu in Solution Explorer, TypeScript JSON Configuration File). Make sure it's actually called 'tsconfig.json'.
• Tools/Options/TypeScript Analyzer and make sure 'Use tsconfig.json files' is set to True.
• Tools/TypeScript Analyzer/Edit TSLint Settings (tslint.json) and add '"no-unused-variable": true,' to the tslint.json file in the rules section.
• Run the analyzer and you should get a no-unused-variable warning: 'a' is declared but never used

There's quite a lot of discussion about this rule on the tslint site, see issues 1481, 2235, 1618, 2933 and there are plenty more issues referenced from those.