Add definitions for jscodeshift/src/testUtils (#36154)

* Add defns for testUtils module

* Import unecessary here, use a reference path instead

* Add testUtils.d.ts to files array instead of reference

types/jscodeshift/index.d.ts

@@ -1,6 +1,7 @@
 // Type definitions for jscodeshift 0.6
 // Project: https://github.com/facebook/jscodeshift#readme
 // Definitions by: Brie Bunge <https://github.com/brieb>
+//                 Brian Jacobel <https://github.com/bjacobel>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.9
 

types/jscodeshift/src/testUtils.d.ts

@@ -0,0 +1,6 @@
+export function defineTest(
+  dirName: string,
+  transformName: string,
+  options: any,
+  testFilePrefix?: string
+): () => any;

types/jscodeshift/test/jscodeshift-tests.ts

@@ -1,4 +1,5 @@
 import { ASTNode, FileInfo, API, Transform, Parser } from "jscodeshift";
+import * as testUtils from "jscodeshift/src/testUtils";
 
 // Can define transform with `function`.
 function replaceWithFooTransform(fileInfo: FileInfo, api: API) {
@@ -73,3 +74,10 @@ const transformWithRecastParseOptions: Transform = (file, { j }) => {
         }
     }
 }
+
+// Can define a test
+testUtils.defineTest(
+    "directory",
+    "transformName",
+    { opt: true },
+);

types/jscodeshift/tsconfig.json

@@ -24,6 +24,7 @@
         "src/collections/Node.d.ts",
         "src/collections/VariableDeclarator.d.ts",
         "src/template.d.ts",
+        "src/testUtils.d.ts",
         "test/jscodeshift-tests.ts",
         "test/js-transforms/bind-this-to-bind-expression.ts",
         "test/js-transforms/call-expression-bind-this-to-arrow-function-expression.ts",