progtest: Return empty array of test cases if none providedv2.11.1

* progtest/src/reader/YamlTestReader.js (loadCases): Handle absence of any
  test cases.
* progtest/test/reader/YamlTestReaderTest.js: New respective test.

2 files changed, 11 insertions, 1 deletions

diff --git a/progtest/src/reader/YamlTestReader.js b/progtest/src/reader/YamlTestReader.js
index a28c1f3..dc0ef3b 100644
--- a/progtest/src/reader/YamlTestReader.js
+++ b/progtest/src/reader/YamlTestReader.js
@@ -71,7 +71,7 @@ module.exports = Class( 'YamlTestReader' )
      */
     'virtual public loadCases'( yaml )
     {
-        const data = this._yamlParser.safeLoad( yaml )
+        const data = ( this._yamlParser.safeLoad( yaml ) || [] )
               .map( this._createTestCase );
 
         return data;
diff --git a/progtest/test/reader/YamlTestReaderTest.js b/progtest/test/reader/YamlTestReaderTest.js
index 9fb26fd..bddc211 100644
--- a/progtest/test/reader/YamlTestReaderTest.js
+++ b/progtest/test/reader/YamlTestReaderTest.js
@@ -52,4 +52,14 @@ describe( "YamlTestReader", () =>
         expect( Sut( mock_parser, case_ctor ).loadCases( yaml ) )
             .to.deep.equal( [ { ok: parsed[0] } ] );
     } );
+
+
+    it( "produces empty array given no tests", () =>
+    {
+        const mock_parser = { safeLoad: () => null };
+        const case_ctor   = () => null;   // unused
+
+        expect( Sut( mock_parser, case_ctor ).loadCases( "" ) )
+            .to.deep.equal( [] );
+    } );
 } );