feat(karma-coverage): align 1.1.2 definition (#41860)

- missing properties of the reporter
- missing JSDoc
- tests updated

Thanks!

types/karma-coverage/index.d.ts

@@ -2,6 +2,7 @@
 // Project: https://github.com/karma-runner/karma-coverage
 // Definitions by: Tanguy Krotoff <https://github.com/tkrotoff>
 //                 Yaroslav Admin <https://github.com/devoto13>
+//                 Piotr Błażejewicz <https://github.com/peterblazejewicz>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 3.2
 
@@ -11,20 +12,65 @@ import * as istanbul from 'istanbul';
 declare module 'karma' {
     interface ConfigOptions {
         /**
-         * See https://github.com/karma-runner/karma-coverage/blob/master/docs/configuration.md
+         * {@link https://github.com/karma-runner/karma-coverage/blob/v1.1.2/docs/configuration.md }
          */
         coverageReporter?: KarmaCoverageReporter & { reporters?: KarmaCoverageReporter[] };
     }
 
-    interface KarmaCoverageReporter {
-        type?: string;
+    /** Reporter type */
+    export type ReporterType = 'html' |
+        'lcov' |
+        'lcovonly' |
+        'text' |
+        'text-summary' |
+        'cobertura' |
+        'teamcity' |
+        'json' |
+        'json-summary' |
+        'in-memory' |
+        'none';
+
+    interface Reporter {
+        type: ReporterType,
         dir?: string;
         subdir?: string | ((browser: string) => string);
+        file?: string;
+    }
+
+    interface KarmaCoverageReporter {
+        /** Specify a reporter type */
+        type?: ReporterType;
+        /** This will be used to output coverage reports. When you set a relative path, the directory is resolved against the basePath. */
+        dir?: string;
+        /** This will be used in complement of the coverageReporter.dir option to generate the full output directory path */
+        subdir?: string | ((browser: string) => string);
+        /** If you use one of these reporters, `cobertura`, `lcovonly`, `teamcity`, `text` or `text-summary`, you may set the file option to specify the output file */
+        file?: string;
+        /** This will be used to configure minimum threshold enforcement for coverage results */
         check?: any;
+        /** This will be used to set the coverage threshold colors */
         watermarks?: any;
+        /**
+         * You can opt to include all sources files, as indicated by the coverage preprocessor,
+         * in your code coverage data, even if there are no tests covering them
+         */
         includeAllSources?: boolean;
+        /** You can opt to specify a source store allowing for external coverage collectors access to the instrumented code. */
         sourceStore?: istanbul.Store;
+        /** You can use multiple reporters, by providing array of options */
+        reporters?: Reporter[];
+        /**
+         * Karma-coverage can infers the instrumenter regarding of the file extension.
+         * It is possible to override this behavior and point out an instrumenter
+         * for the files matching a specific pattern.
+         */
         instrumenter?: any;
+        /**
+         * If set to true, then CoffeeScript files instrumented with Ibrik will use
+         * the .js extension for the transpiled source (without this option,
+         * the JavaScript files will keep the original .coffee extension)
+         */
+        useJSExtensionForCoffeeScript?: boolean;
         [moreSettings: string]: any;
     }
 }

types/karma-coverage/karma-coverage-tests.ts

@@ -21,7 +21,13 @@ module.exports = function(config: karma.Config) {
     // optionally, configure the reporter
     coverageReporter: {
       type: 'html',
-      dir: 'coverage/'
+      dir: 'coverage/',
+      // $ExpectType (browser: string) => string
+      subdir: (browser) => {
+          return `cool-${browser}-directory`;
+      },
+      // $ExpectType string
+      file: 'index.html',
     }
   });
 };
@@ -72,6 +78,7 @@ module.exports = function(config: karma.Config) {
   config.set({
     coverageReporter: {
       dir: 'coverage',
+      // $ExpectType string
       subdir: '.'
       // Would output the results into: .'/coverage/'
     }