Merge pull request #464 from typed-ember/isolated-modules-and-cli-version-warning

[v2] Check off a couple remaining todo items

Author: chriskrycho

blueprint-files/ember-cli-typescript/tsconfig.json

@@ -3,6 +3,7 @@
     "target": "es2017",
     "allowJs": true,
     "moduleResolution": "node",
+    "isolatedModules": true,
     "allowSyntheticDefaultImports": true,
     "noImplicitAny": true,
     "noImplicitThis": true,

ts/addon.ts

@@ -14,7 +14,7 @@ export default addon({
   included() {
     this._super.included.apply(this, arguments);
     this._checkDevelopment();
-    this._checkBabelVersion();
+    this._checkPeerVersions();
 
     // If we're a direct dependency of the host app, go ahead and start up the
     // typecheck worker so we don't wait until the end of the build to check
@@ -87,7 +87,7 @@ export default addon({
     return !['in-repo-a', 'in-repo-b'].includes(addon.name);
   },
 
-  _checkBabelVersion() {
+  _checkPeerVersions() {
     let babel = this.parent.addons.find(addon => addon.name === 'ember-cli-babel');
     let version = babel && babel.pkg.version;
     if (!babel || !(semver.gte(version!, '7.1.0') && semver.lt(version!, '8.0.0'))) {
@@ -97,6 +97,15 @@ export default addon({
           'your TypeScript files may not be transpiled correctly.'
       );
     }
+
+    let cliPackage = this.project.require('ember-cli/package.json') as { version: string };
+    if (semver.lt(cliPackage.version, '3.5.0')) {
+      this.ui.writeWarnLine(
+        'ember-cli-typescript works best with ember-cli >= 3.5, which uses the system temporary directory ' +
+          'by default rather than a project-local one, minimizing file system events the TypeScript ' +
+          'compiler needs to keep track of.'
+      );
+    }
   },
 
   _checkDevelopment() {

ts/tests/blueprints/ember-cli-typescript-test.js

@@ -72,6 +72,7 @@ describe('Acceptance: ember-cli-typescript generator', function() {
 
         expect(tsconfigJson.compilerOptions.inlineSourceMap).to.equal(true);
         expect(tsconfigJson.compilerOptions.inlineSources).to.equal(true);
+        expect(tsconfigJson.compilerOptions.isolatedModules).to.equal(true);
 
         expect(tsconfigJson.include).to.deep.equal(['app/**/*', 'tests/**/*', 'types/**/*']);