feat(karma-json-preprocessor): new type definition (#42738)

- type definitions
- tests

https://github.com/mjeanroy/karma-json-preprocessor#configuration

Thanks!

types/karma-json-preprocessor/index.d.ts

@@ -0,0 +1,31 @@
+// Type definitions for karma-json-preprocessor 0.3
+// Project: https://github.com/mjeanroy/karma-json-preprocessor#readme
+// Definitions by: Piotr Błażejewicz (Peter Blazejewicz) <https://github.com/peterblazejewicz>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 3.2
+
+import 'karma';
+
+declare module 'karma' {
+    interface ConfigOptions {
+        /**
+         * see {@link https://github.com/mjeanroy/karma-json-preprocessor#configuration-1}
+         */
+        jsonPreprocessor?: JsonPreprocessorOptions;
+    }
+
+    /**
+     * Default global variable name is by default `__json__`,
+     * but you can override it with your own name in karma configuration:
+     */
+    interface JsonPreprocessorOptions {
+        /**
+         * @default '__json__'
+         */
+        varName?: string;
+        /**
+         * @default ''
+         */
+        stripPrefix?: string;
+    }
+}

types/karma-json-preprocessor/karma-json-preprocessor-tests.ts

@@ -0,0 +1,20 @@
+import karma = require('karma');
+
+// Mocha reporter options tests
+const mochaReporter: karma.JsonPreprocessorOptions = {
+    varName: '$json',
+    stripPrefix: 'prefix',
+};
+
+module.exports = (config: karma.Config) => {
+    config.set({
+        preprocessors: {
+            '**/*.json': ['json'],
+        },
+        files: ['**/*.js', '**/*.json'],
+        jsonPreprocessor: {
+            varName: '$json',
+            stripPrefix: 'prefix',
+        },
+    });
+};

types/karma-json-preprocessor/tsconfig.json

@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "karma-json-preprocessor-tests.ts"
+    ]
+}

types/karma-json-preprocessor/tslint.json

@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }