bugfix: Ensure 'debug test' codelens only tests the selected test. (#…

…1561)

If you have two functions `TestFoo` and `TestFooTwo`, and select
'debug test' on `TestFoo`, both tests will be executed. This happens
because `go test -test.run` expects a regular expression, but we were
only passing it a function name. Fixed by wrapping the function name
in start/end markers.

src/goRunTestCodelens.ts

@@ -82,7 +82,7 @@ export class GoRunTestCodeLensProvider extends GoBaseCodeLensProvider {
 					arguments: [{ functionName: func.name }]
 				};
 
-				const args = ['-test.run', func.name];
+				const args = ['-test.run', '^' + func.name + '$'];
 				const program = path.dirname(document.fileName);
 				const env = Object.assign({}, this.debugConfig.env, vsConfig['testEnvVars']);
 				const envFile = vsConfig['testEnvFile'];