test: Delete some cached files in tests.

This change ensures that the precompile tests that exercise package
naming properly read package.json and index.js from disk. This makes it
so the test fails without the moduleName() fix in the prior commit.

Author: Tim Lindvall

ts/tests/commands/precompile-test.ts

@@ -1,4 +1,5 @@
 import * as fs from 'fs-extra';
+import * as path from 'path';
 import { hook } from 'capture-console';
 import ember from 'ember-cli-blueprint-test-helpers/lib/helpers/ember';
 import blueprintHelpers from 'ember-cli-blueprint-test-helpers/helpers';
@@ -109,6 +110,13 @@ describe('Acceptance: ts:precompile command', function () {
     pkg.name = '@foo/my-addon'; // addon `name` is `my-addon`
     fs.writeJSONSync('package.json', pkg);
 
+    // CAUTION! HACKY CODE AHEAD!
+    // The ember blueprint helper stays in the same node process, so require
+    // keeps any previously read files cached. We need to clear out these
+    // caches so it picks up the changes properly.
+    delete require.cache[path.join(process.cwd(), 'index.js')];
+    delete require.cache[path.join(process.cwd(), 'package.json')];
+
     return ember(['ts:precompile']).then(() => {
       const declaration = file('test-support/test-file.d.ts');
       expect(declaration).to.exist;
@@ -136,6 +144,13 @@ describe('Acceptance: ts:precompile command', function () {
     pkg.name = '@foo/my-addon'; // addon `moduleName()` is `my-addon`
     fs.writeJSONSync('package.json', pkg);
 
+    // CAUTION! HACKY CODE AHEAD!
+    // The ember blueprint helper stays in the same node process, so require
+    // keeps any previously read files cached. We need to clear out these
+    // caches so it picks up the changes properly.
+    delete require.cache[path.join(process.cwd(), 'index.js')];
+    delete require.cache[path.join(process.cwd(), 'package.json')];
+
     return ember(['ts:precompile']).then(() => {
       const componentDecl = file('components/my-component.d.ts');
       expect(componentDecl).to.exist;