Fixed preprocessor setup. No correctly detects missing tsconfig.json and skips.

Author: simonihmig

index.js

@@ -1,26 +1,25 @@
 /* eslint-env node */
 
+const fs = require('fs');
+const path = require('path');
 const SilentError = require('silent-error');
+const TsPreprocessor = require('./lib/typescript-preprocessor');
 
-let TsPreprocessor;
-try {
-  TsPreprocessor = require('./lib/typescript-preprocessor');
-} catch (ex) {
-  // Do nothing; we just won't have the plugin available. This means that if you
-  // somehow end up in a state where it doesn't load, the preprocessor *will*
-  // fail, but this is necessary because the preprocessor depends on packages
-  // which aren't installed until the
-}
 
 module.exports = {
   name: 'ember-cli-typescript',
 
   setupPreprocessorRegistry(type, registry) {
-    if (!TsPreprocessor) {
-      this.ui.write(
-        'Note: TypeScript preprocessor not available -- some dependencies not installed. ' +
-          '(If this is during installation of the add-on, this is as expected. If it is ' +
-          'while building, serving, or testing the application, this is an error.)'
+    if (!fs.existsSync(path.join(this.project.root, 'tsconfig.json'))) {
+      // Do nothing; we just won't have the plugin available. This means that if you
+      // somehow end up in a state where it doesn't load, the preprocessor *will*
+      // fail, but this is necessary because the preprocessor depends on packages
+      // which aren't installed until the default blueprint is run
+
+      this.ui.writeInfoLine(
+        'Skipping TypeScript preprocessing as there is no tsconfig.json. ' +
+        '(If this is during installation of the add-on, this is as expected. If it is ' +
+        'while building, serving, or testing the application, this is an error.)'
       );
       return;
     }
@@ -30,7 +29,7 @@ module.exports = {
         ui: this.ui
       }));
     } catch (ex) {
-      throw new SilentError(`Missing or invalid tsconfig.json, please fix or run \`ember generate ember-cli-typescript\`.\n${ex}`);
+      throw new SilentError(`Failed to instantiate TypeScript preprocessor, probably due to an invalid tsconfig.json. Please fix or run \`ember generate ember-cli-typescript\`.\n${ex}`);
     }
   },
 };