fix(ngc): work with typescript@next

This is required due to breaking change in TS, see
microsoft/TypeScript#8841 (comment)

Author: alexeagle

scripts/ci-lite/offline_compiler_test.sh

@@ -31,11 +31,16 @@ cp -v package.json $TMP
   # TODO(alexeagle): allow this to be npm link instead
   npm install ${LINKABLE_PKGS[*]}
 
+  ./node_modules/.bin/tsc --version
   # Compile the compiler-cli integration tests
   ./node_modules/.bin/ngc
   ./node_modules/.bin/ng-xi18n
 
   ./node_modules/.bin/jasmine init
   # Run compiler-cli integration tests in node
   ./node_modules/.bin/jasmine test/*_spec.js
+
+  # Compile again with a differently named tsconfig file
+  mv tsconfig.json othername.json
+  ./node_modules/.bin/ngc -p othername.json
 )

tools/@angular/tsc-wrapped/src/tsc.ts

@@ -54,9 +54,11 @@ export class Tsc implements CompilerInterface {
     this.basePath = basePath;
 
     // Allow a directory containing tsconfig.json as the project value
+    // Note, TS@next returns an empty array, while earlier versions throw
     try {
-      this.readDirectory(project);
-      project = path.join(project, 'tsconfig.json');
+      if (this.readDirectory(project).length > 0) {
+        project = path.join(project, 'tsconfig.json');
+      }
     } catch (e) {
       // Was not a directory, continue on assuming it's a file
     }